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Vishnudutt Purohit, Jag Khalsa, and Jose Serrano.  Mechanisms of alcohol-associated cancers: Introduction and summary of the symposium.  Alcohol 35(3):155-160, April 2005.

Summary:  This article introduces an issue of the journal devoted to an international symposium on Mechanisms of Alcohol-Associated Cancers. The symposium, which was held at Bethesda, Maryland in October 2004, was sponsored by several components of the National Insitutes of Health, including the National Institute on Alcohol Abuse and Alcoholism, the Office of Dietary Supplements, the Office of Rare Diseases, the National Cancer Institute, the National Institute on Drug Abuse, and the National Institute of Diabetes and Digestive and Kidney Diseases. The following mechanisms were examined: (1) production of acetaldehyde, a weak mutagen and carcinogen; (2) induction of cytochrome P450 2E1 and associated oxidative stress and conversion of procarcinogens to carcinogens; (3) depletion of S-adenosylmethionine and, consequently, induction of global deoxyribonucleic acid hypomethylation; (4) induction of increased production of inhibitory guanine nucleotide regulatory proteins and components of extracellular signal-regulated kinase–mitogen-activated protein kinase signaling; (5) accumulation of iron and associated oxidative stress; (6) inactivation of the tumor suppressor gene BRCA1 and increased estrogen responsiveness (primarily in breast); and (7) impairment of retinoic acid metabolism. Nicotine may promote carcinogenesis through activation of extracellular signal-regulated kinase/cyclooxygenase-2/vascular endothelial growth factor signaling pathway. NIAAA Glossary Terms:  conference proceedings, cancer, AODR disorder, ethanol, enzymes, cytochrome P450 2E1, biochemical mechanism, oxidative stress, carcinogens, carcinogenesis, DNA, S-adenosylmethionine, acetaldehyde, mutation, guanine nucleotides, regulatory proteins, cell signaling, protein kinases mitogens, retinoic acid, iron, estrogens, gene, nicotine, growth factors, literature review

Linda Morris Brown.  Epidemiology of alcohol-associated cancers.  Alcohol 35(3):161-168, April 2005.

Summary: This paper was presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004. Alcohol, especially in combination with smoking, is a well-established risk factor for cancers of the oral cavity, pharynx, larynx, and esophagus, with 25% to 80% of these cancers being attributable to alcohol. Rates of these cancers in the United States have been decreasing in recent years, possibly because of reduced cigarette smoking and alcohol use. Although epidemiologic evidence has associated chronic alcohol consumption with increased risk of liver cancer, the rising rates of this cancer in the United States are most likely due to the increasing prevalence of chronic hepatitis B and C infections. Epidemiologic evidence has linked light to moderate drinking to colorectal cancers and female breast cancer, both of which are common in developed countries. Although most epidemiologic studies have provided little or no support for a causal relation between light and moderate alcohol use and risk of pancreatic cancer, a possible role of heavy alcohol consumption cannot be ruled out. Further studies of these cancers are needed to clarify the role of type of alcoholic beverage, the role of alcohol concentration, and the dose-response curve at low alcohol concentrations. Future research also should use uniform ways to report alcohol intake and uniform measures for analysis, include the investigation of alcohol-associated cancer risks in U.S. minority populations, enhance experimental work to better understand the underlying mechanisms through which alcohol promotes carcinogenesis, and develop preventive strategies. NIAAA Glossary Terms:  conference proceedings, cancer, AODR disorder, ethanol, risk factors, oral disorder, respiratory airway, larynx, pharynx, esophageal disorder, smoking, chronic AODE, liver disorder, hepatitis B, hepatitis C, epidemiological indicators, epidemiology, breast, light AOD use, moderate AOD use, pancreatic disorder, alcoholic beverage, dose-response relationship, AOD intake per occasion, AOD consumption, minority group, carcinogenesis, causal pathways, prevention strategy, research agenda, literature review

Graham R. Ogden.  Alcohol and oral cancer.  Alcohol 35(3):169-173, April 2005.

Summary: Alcohol, particularly when associated with tobacco use, has been recognized as an important risk factor for oral cancer for nearly 50 years. The combination of drinking and smoking is associated with approximately 75% of upper aerodigestive tract cancers. This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, reviews the potential role of alcohol in the development of oral cancer. The effect of alcohol on cellular structure and function is considered by reference to histologic and exfoliative cytologic studies of the oral epithelia. Alcohol may influence the proliferative cells by both intracellular (e.g., endocytosis) and intercellular (permeability) pathways. The carcinogenic exposure of the proliferating stem cells in the basal layer may be regulated through these pathways. Individual variation might help explain why oral cancer arises in some people who smoke and consume excess alcohol, but not in most. Efforts to reduce this burden on the individual and society must be directed toward patient and professional education and research on genetic susceptibility. NIAAA Glossary Terms:  conference proceedings, cancer, AODR disorder, ethanol, AOD use, alcoholic beverage, tobacco in any form, risk factors, oral disorder, carcinogenesis, cell and cell structure, cell function, histologic study, endocytosis, membrane permeability, epithelium, stem cell, smoking, heavy AOD use, individual differences, genetic trait, genetic variance, prevention through education, literature review

Yokoyama A, and Omori T.  Genetic polymorphisms of alcohol and aldehyde dehydrogenases and risk for esophageal and head and neck cancers (literature review).  Alcohol 35(3):175-185, April 2005.

(No abstract available.)

Philip J. Brooks and Jacob A. Theruvathu.  DNA adducts from acetaldehyde: Implications for alcohol-related carcinogenesis.  Alcohol 35(3):187-193, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines the role of deoxyribonucleic acid (DNA)-acetaldehyde adducts in alcohol-related carcinogenesis. Alcohol consumption is causally related to increased risk of cancer of the upper gastrointestinal tract, and the formation of acetaldehyde from ethanol metabolism seems to be the major underlying mechanism. Acetaldehyde is carcinogenic in rodents and causes sister chromatid exchanges and chromosomal aberrations in human cells. The best-studied DNA-acetaldehyde adduct is N2-ethyl-2′-deoxyguanosine, which is increased in liver DNA from ethanol-treated rodents and in white blood cells from human alcohol abusers. However, evidence of its mutagenicity in mammalian cells is lacking. Another adduct, 1,N2-propano-2′-deoxyguanosine (PdG), which is formed from acetaldehyde in the presence of histones and other basic molecules, has been shown to be responsible for the genotoxic and mutagenic effects of crotonaldehyde. This adduct can exist either as a ring-closed form or a ring-opened aldehyde form. Whereas the ring-closed form is mutagenic, the aldehyde form can participate in the formation of secondary lesions, including DNA-protein cross-links and DNA interstrand cross-links. The formation of these types of complex secondary DNA lesions resulting from PdG may explain many of the observed genotoxic effects of acetaldehyde. Repair of PdG and its associated adducts is complex, involving multiple pathways. Inherited variation in the genes encoding the proteins involved in PdG repair and its secondary adducts may contribute to susceptibility to alcohol-related carcinogenesis. NIAAA Glossary Terms:  conference proceedings, cancer, AODR disorder, carcinogenesis, adduct, DNA, proteins, acetaldehyde, ethanol metabolism, mutation, animal study, human study, laboratory rat, laboratory mice, deoxyribonucleosides, individual differences, genetic variance, biochemical mechanism, literature review

Iain H. McKillop and Laura W. Schrum.  Alcohol and liver cancer.  Alcohol 35(3):195-203, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines alcohol consumption as a risk factor for liver cancer. Hepatocellular carcinoma, the eighth most frequent cancer in the world, accounts for approximately 500,000 deaths a year. Unlike many malignancies, hepatocellular carcinoma occurs predominantly in association with known risk factors, with cirrhosis being the most common precursor to its development. The liver is the major site of ethanol metabolism, in which alcohol dehydrogenase catalyzes the formation of acetaldehyde and free radicals. These bind rapidly to numerous cellular targets, including components of cell signaling pathways and deoxyribonucleic acid (DNA). In addition to direct DNA damage, acetaldehyde depletes glutathione, an antioxidant involved in detoxification. Chronic alcohol abuse leads to induction of hepatocyte microsomal cytochrome P450 2E1, an enzyme that metabolizes ethanol to acetaldehyde, resulting in further free radical production and aberrant cell function. Cytochrome P450 2E1-dependent ethanol metabolism is also associated with activation of procarcinogens, changes in cell cycle, nutritional deficiencies, and altered immune system responses. The identification of oxidative stress in mediating many deleterious effects of ethanol in the liver has led to renewed interest in the use of dietary antioxidants, including S-adenosyl-L-methionine and plant-derived flavonoids, as therapeutic agents. NIAAA Glossary Terms:  conference proceedings, cancer, liver disorder, AODR disorder, ethanol, carcinoma, hepatocyte, risk factors, liver cirrhosis, ethanol metabolism, alcohol dehydrogenases, acetaldehyde, free radicals, cell signaling, DNA, oxidative stress, glutathione, antioxidants, detoxification, chronic AODE, inducible enzymes, cytochrome P450 2E1, S-adenosylmethionine, flavonoids, drug therapy, literature review

Vay Liang W. Go, Anna Gukovskaya, and Stephen J. Pandol.  Alcohol and pancreatic cancer.  Alcohol 35(3):205-211, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines alcohol consumption as a risk factor for pancreatic cancer. Heavy alcohol consumption is known to be a major cause of chronic pancreatitis and a risk factor for type 2 diabetes mellitus, both of which are linked to pancreatic cancer. It has been established that an extensive normal interaction exists between the exocrine and endocrine pancreas, as well as in inflammatory processes and carcinogenesis. Alcohol and its metabolites (acetaldehyde and fatty acid ethyl esters) can alter metabolic pathways involved in the inflammatory response and carcinogenesis by one or more of the following mechanisms: (1) premature activation of zymogens; (2) induction of the inflammatory response through activation of nuclear transcription factors, including nuclear factor-kappa and activation protein 1; (3) increased production of reactive oxygen species, resulting in oxidative DNA damage and altered effect of dietary antioxidants; (4) activation of pancreatic stellate cells, leading to fibrosis; (5) mutation of genes for enzymes related to cytochrome P450, glutathione S-transferase, aldehyde dehydrogenase, cationic trypsinogen, and pancreatic secretory trypsin inhibitor; (6) synergistic effects of ethanol and tobacco on metabolism of NNK (a tobacco-specific nitrosamine carcinogen); and (7) dysregulation of proliferation and apoptosis. These various metabolic effects of alcohol can lead to or interact with other risk factors (genetic, dietary, environmental, and lifestyle factors) that result in acute and chronic pancreatitis and diabetes mellitus and, ultimately, affect the multistep process toward the development of pancreatic cancer. NIAAA Glossary Terms:  conference proceedings, pancreatic disorder, cancer, AODR disorder, AOD consumption, heavy AOD use, chronic pancreatitis, endocrine pancreas, exocrine pancreas, inflammation, carcinogenesis, ethanol metabolism, acetaldehyde, fatty acid ethyl esters, enzymes, gene transcription, nuclear factor-kappa B, biological activation, oxygen radicals, antioxidants, pancreatic stellate cell, fibrosis, mutation, cytochrome P450, glutathione S-transferases, alcehyde dehydrogenases, trypsin, enzyme inhibitors, synergistic drug interaction, tobacco in any form, alcoholic beverage, nitrosamine, apoptosis, cell proliferation, risk factors, genetic variance, diet, environmental factors, lifestyle, acute AODE, chronic AODE, literature review

Ramona G. Dumitrescu and Peter G. Shields.  The etiology of alcohol-induced breast cancer.  Alcohol 35(3):213-225, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, discusses the etiology of alcohol-induced breast cancer. Most epidemiologic studies in women, as well as most experimental studies in animals, have shown that alcohol consumption is associated with increased breast cancer risk. Several possible mechanisms are examined. Alcohol-metabolizing enzymes are present in human breast tissue, and acetaldehyde, the first metabolic product of ethanol, is a known mutagen. Although acetaldehyde is only weakly mutagenic, results of some human studies implicate it in the context of genetic susceptibilities to increased ethanol metabolism. Reactive oxygen species resulting from ethanol metabolism may be involved in breast carcinogenesis by causing damage, as well as by generating adducts with DNA and proteins. Alcohol interferes with estrogen pathways in multiple ways, influencing hormone levels and effects on the estrogen receptors. Alcohol can negatively affect folate levels, and the folate perturbation affects DNA methylation and DNA synthesis, which is important in carcinogenesis. Some studies indicate that genetic variants of one-carbon metabolism genes might increase risk of alcohol-related breast cancer. For all these pathways, genetic polymorphisms might play a role in increasing further a woman's risk for breast cancer. Additional studies are needed to determine the relative importance of these pathways, as well as the modifying influence by genetic variation. NIAAA Glossary Terms:  conference proceedings, cancer, breast, AODR disorder, risk factors, female, AOD consumption, ethanol metabolism, acetaldehyde, ethanol-to-acetaldehyde metabolism, mutagenesis, genetic trait, oxygen radicals, adduct, DNA, proteins, estrogens, receptors, folates, DNA metabolism, genetic polymorphism, biochemical mechanism, literature review

Shelly C. Lu and José M. Mato.  Role of methionine adenosyltransferase and S-adenosylmethionine in alcohol-associated liver cancer.  Alcohol 35(3):227-234, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines the roles of essential enzyme methionine adenosyltransferase (MAT) and the principal methyl donor S-adenosylmethionine (SAMe) in the pathogenesis of alcohol-related liver cancer. The genes (MAT1A and MAT2A) encode for MAT, which catalyzes the biosynthesis of SAMe, is a precursor of glutathione in the liver. MAT1A is expressed mostly in the liver, whereas MAT2A is widely distributed. MAT2A is induced in the liver during periods of rapid growth and dedifferentiation. In human hepatocellular carcinoma (HCC) MAT1A is replaced by MAT2A. This has pathogenic importance because MAT2A expression is associated with lower SAMe levels and faster growth, whereas exogenous SAMe treatment inhibits growth. Rats fed ethanol intragastrically for 9 weeks also exhibit a relative switch in hepatic MAT expression, decreased SAMe levels, hypomethylation of c-myc oncogene, increased c-myc expression, and increased accumulation of DNA strand breaks. Patients with alcoholic liver disease have decreased hepatic MAT activity due to decreased MAT1A expression and inactivation of MAT1A-encoded isoenzymes, culminating in decreased SAMe biosynthesis. Consequences of chronic hepatic SAMe depletion have been examined in MAT1A knockout mice, which have increased susceptibility to liver injury; they develop spontaneous steatohepatitis by 8 months, and HCC by 18 months. There is growing evidence that, in addition to being a methyl donor, SAMe controls hepatocyte growth response and death response. Transient SAMe depletion is necessary for liver regeneration, but chronic hepatic SAMe depletion may lead to malignant transformation. Interestingly, SAMe is antiapoptotic in normal hepatocytes, but proapoptotic in liver cancer cells, which should make it useful for both chemoprevention and treatment of HCC. NIAAA Glossary Terms:  conference proceedings, alcoholic liver disorder, cancer, AODR disorder, S-adenosylmethionine, gene, gene expression, glutathione, carcinoma, hepatocyte, pathogenesis, intragastric administration, isoenzyme, oncogene, gene knockout technology, fatty liver, hepatitis, apoptosis, drug therapy, literature review

Joel B. Mason and Sang-Woon Choi.  Effects of alcohol on folate metabolism: Implications for carcinogenesis.  Alcohol 35(3):235-241, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines the carcinogenetic implications of ethanol's effects on folate metabolism. Epidemiological studies implicate excess ethanol ingestion as well as low dietary folate intake as risk factors for several cancers, and support the concept that these two factors act synergistically. The relation is biologically plausible because ethanol reduces the bioavailability of dietary folate and inhibits certaint folate-dependent biochemical reactions. For example, alcohol ingestion in animals is known to inhibit folate-mediated methionine synthesis. This may interrupt critical methylation processes mediated by S-adenosylmethionine, the activated form of methionine. Consistent with the observed inhibition of methionine synthesis is the observation that chronic alcohol ingestion in laboratory animals is known to produce hypomethylation of DNA in the colonic mucosa, a constant feature of early colorectal neoplasia. Inhibition of methionine synthase also creates a "methylfolate trap," analogous to what occurs in vitamin B12 deficiency. There is also some evidence that alcohol may redirect the utilization of folate toward serine synthesis, thereby interfering with a critical function of methylenetetrahydrofolate, namely thymidine synthesis. Although a mechanistic link between alcohol and impaired folate metabolism in carcinogenesis is still not definitively established, such a link should be pursued in future studies because of the intimate metabolic relation between alcohol and folate metabolism. NIAAA Glossary Terms:  conference proceedings, ethanol, folates, metabolism, AODR disorder, cancer, carcinogenesis, risk factors, synergistic drug interaction, bioavailability, biochemical mechanism, S-adenosylmethionine, methionine, chronic AODE, DNA metabolism, colon, intestinal mucosa, neoplasm, synthetases, vitamin B12, nutritional deficiency, literature review

Dennis R. Petersen.  Alcohol, iron-associated oxidative stress, and cancer.  Alcohol 35(3):243-249, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines the role of ethanol-induced iron accumulation, and consequent oxidative stress, in the pathogenesis of liver cancer. Oxidative stress plays an important role in the initiation and promotion events of carcinogenesis. Alcoholic liver disease is associated with significant oxidative stress as well as the hepatic accumulation of iron, a transition element that also initiates oxidative stress. The combined prooxidant potentials of ethanol and iron are at least additive and may be synergistic in the induction of hepatocellular oxidative stress and antioxidant depletion. One cellular consequence of sustained oxidative stress and redox imbalance resulting from the combined actions of alcohol and iron is lipid peroxidation, resulting in the production of aldehydic products such as 4-hydroxy-2-nonenal, which has been linked to site-specific mutations of the p53 gene. In addition, the accumulation of iron in hepatic macrophages isolated from laboratory animals chronically ingesting alcohol is associated with activation of nuclear factor-kappa B and production of tumor necrosis factor-alpha, providing a proinflammatory cellular environment also favorable for initiation and promotion of carcinogenesis. Consequently, there is persuasive evidence that the potential of ethanol and iron to induce oxidative stress may be an important pathogenic mechanism for the increased occurrence of hepatocellular carcinoma in individuals with hepatic iron overload who ingest alcohol. NIAAA Glossary Terms:  conference proceedings, cancer, carcinoma, liver, AODR disorder, carcinogenesis, iron metabolism disorder, oxidative stress, synergistic drug interaction, hepatocyte, antioxidants, peroxidation, lipids, oxidation-reduction, mutation,  biogenic aldehyde, aldehydes, macrophage, nuclear factor-kappa B, tumor necrosis factor-alpha, inflammation, pathogenesis, literature review

Xiang-Dong Wang.  Alcohol, vitamin A, and cancer.  Alcohol 35(3):251-258, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines the role of alcohol-associated vitamin A deficiency in the etiology of cancer. Chronic and excessive alcohol intake is associated with increased risk of a variety of cancers. Retinoids (vitamin A and its derivatives) exert profound effects on cellular growth, cellular differentiation, and apoptosis, thereby controlling carcinogenesis. Lower hepatic vitamin A levels in alcoholics are well documented. Research on the mechanisms by which excessive alcohol interferes with retinoid metabolism shows that (1) alcohol acts as a competitive inhibitor of vitamin A oxidation to retinoic acid, which is catalyzed by alcohol dehydrogenases and acetaldehyde dehydrogenases; (2) alcohol-induced cytochrome P450 enzymes (CYP), particularly CYP 2E1, enhance catabolism of vitamin A and retinoic acid; and (3) alcohol alters retinoid homeostasis by increasing vitamin A mobilization from liver to extrahepatic tissues. Consequently, long-term and excessive alcohol intake results in impaired status of retinoic acid, the most active vitamin A derivative and a ligand for both retinoic acid receptors and retinoid X receptors. Alcohol-impaired retinoic acid homeostasis also interferes with retinoic acid signaling (e.g., down-regulates retinoid target gene expression) and retinoic acid "cross-talk" with the mitogen-activated protein kinase (MAPK) signaling pathway. Retinoic acid supplementation restores the normal status of both retinoid and MAPK signaling, thereby maintaining normal cell proliferation and apoptosis in alcohol-fed animals. Use of retinoids for prevention of alcohol-related carcinogenesis in humans will require improved understanding of the alcohol-retinoid interaction and the molecular mechanisms involved, particularly the detrimental effects of polar metabolites of vitamin A. NIAAA Glossary Terms:  conference proceedings, cancer, etiology, AODR disorder, heavy AOD use, chronic AODE, vitamin A deficiency, retinoids, retinoic acid, cell proliferation,  cell growth and differentiation, apoptosis, alcohol dehydrogenases, cytochrome P450, cytochrome P450 2E1, inducible enzymes, enzyme induction, ligand, receptors, homeostasis, cell signaling, gene expression, mitogens, protein kinases, literature review

Vivian Y. Shin and Chi-Hin Cho.  Nicotine and gastric cancer.  Alcohol 35(3):259-264, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, examines nicotine as a risk factor for gastric cancer. About 60 cigarette smoke components are considered to be carcinogens, namely polycyclic aromatic hydrocarbons, nitrosamines, aromatic amine, trace metals, as well as nicotine. One of the active components in cigarette smoke is nicotine, which has an ambiguous association with tumorigenesis. Nonsteroidal antiinflammatory drugs are widely used as antitumor agents to treat patients with cancer by inhibiting cyclooxygenase-2 activity. Stimulation of tumor growth by nicotine involves different processes of cell proliferation and angiogenesis. Results from studies using animal xenograft models and cell cultures show that nicotine stimulates tumor growth through a cyclooxygenase-2–dependent pathway. Based on these findings, nicotine seems to be a potent mitogenic agent in modulating tumor cell proliferation, and selective cyclooxygenase-2 inhibitors are promising antitumor agents for gastric cancer in smokers. NIAAA Glossary Terms:  conference proceedings, nicotine, gastric disorder, cancer, carcinogenesis, smoking, cigarette, carcinogens, polycyclic hydrocarbons, nitrosamine, amines, aromatic hydrocarbons, inflammation, drug therapy, cyclooxygenase inhibitors, cell proliferation, angiogenesis, mitogens, enzyme inhibitors, literature review

Mia Hashibe, Kurt Straif, Donald P. Tashkin, Hal Morgenstern, Sander Greenland, and Zuo-Feng Zhang.  Epidemiologic review of marijuana use and cancer risk.  Alcohol 35(3):265-275, April 2005.

Summary: This paper, presented at a symposium on Mechanisms of Alcohol-Associated Cancers, held at Bethesda, Maryland in October 2004, reviews the epidemiology of cancer risk associated with marijuana use. Although young adults consider marijuana to be the least risky illicit drug, marijuana smoke contains several of the same carcinogens and co-carcinogens as tobacco tar, raising concerns that marijuana smoking may be a risk factor for tobacco-related cancers. The authors reviewed two cohort studies and 14 case-control studies with assessment of the association of marijuana use and cancer risk. Increased risks of lung or colorectal cancer due to marijuana smoking were not observed in the cohort studies. However, increased risks of prostate and cervical cancers among non-tobacco smokers, as well as adult-onset glioma among tobacco and non-tobacco smokers, were observed. The 14 case-control studies included 4 studies on head and neck cancers, 2 on lung cancer, 2 on non-Hodgkin's lymphoma, 1on anal cancer, 1 on penile cancer, and 4 on childhood cancers with assessment of parental exposures. Zhang et al. reported that marijuana use may increase risk of head and neck cancers in a hospital-based case-control study, with dose-response relations for both frequency and duration of use. However, Rosenblatt et al. reported no association between oral cancer and marijuana use in a population-based case-control study. An eightfold increase in lung cancer risk among marijuana users was observed in a lstudy in Tunisia, but there was no dose-response assessment, and marijuana may have been mixed with tobacco. Parental marijuana use during gestation was associated with increased risks of childhood leukemia, astrocytoma, and rhabdomyosarcoma, but dose-response relations were not assessed. In summary, not enough studies are available for adequate evaluation of marijuana impact on cancer risk. Several limitations of previous studies include possible underreporting where marijuana use is illegal, small sample sizes, and too few heavy marijuana users in the study sample. It is recommended that future studies focus on tobacco-related cancer sites; obtain detailed marijuana exposure assessment including frequency, duration, and amount of personal use as well as mode of use (cigarette, pipe, bong, or taken orally); adjust for tobacco smoking and conduct analyses on nonusers of tobacco; and use larger samples, meta-analyses, or pooled analyses to maximize statistical precision and investigate sources of differences in results. NIAAA Glossary Terms:  conference proceedings, marijuana in any form, cancer, carcinogens, carcinogenesis, AODR disorder, smoking, risk factors, risk analysis, lung disorder, head, neck, male genitals, case-control study, dose-response relationship, AOD use frequency, AOD use duration, AOD use pattern, parental AOD use, illicit drug, sample selection problems, meta-analysis, research issue, literature review

Jian-Ching Ren, Ali Banan, Ali Keshavarzian, Qianlong Zhu, Nancy LaPaglia, John McNulty, Nicholas V. Emanuele, and Mary Ann Emanuele.  Exposure to ethanol induces oxidative damage in the pituitary gland.  Alcohol 35(2):91-101, February 2005.

Summary: Chronic exposure of pubertal male rats to ethanol results in decreased serum testosterone and decreased or inappropriately normal serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, suggesting a functional defect in the pituitary. Animal studies support a role for ethanol-induced oxidative damage in the pathophysiology, but evidence in the pituitary is limited. This study examined markers of oxidative damage to lipids and proteins in pituitaries from rats consuming ethanol for 5, 10, 20, 30, and 60 days as well as markers of damage to nucleic acids in pituitaries after 60 days of ethanol consumption. There were increases in 8-oxo-deoxyguanosine immunoreactivity, a marker of oxidative damage to nucleic acids, and an overall increase in the lipid peroxidation markers malondialdehyde and 4-hydroxynonenal. Markers of protein oxidation (protein carbonylation and protein nitrotyrosination), were significantly increased after 30 and 60 days of ethanol consumption respectively. After 60 days of ethanol exposure, tranferase dUTP nick end labeling (TUNEL) assay revealed that cell death in the ethanol-treated pituitaries was not significantly different from that in the pair-fed controls at the time of examination. Serum testosterone, FSH, and LH were also measured after ethanol consumption for 5, 10, 20, 30, and 60 days. Testosterone levels were consistently lower through 5 to 60 days of ethanol exposure, whereas LH and FSH were inappropriately unchanged, suggesting pituitary malfunction. The results provide evidence for ethanol-induced oxidative damage to the pituitary, which may contribute to pituitary dysfunction. NIAAA Glossary Terms:  ethanol, testosterone, luteinizing hormone, follicle-stimulating hormone, chronic AODE, pituitary, oxidative stress, lipids, proteins, nucleic acids, peroxidation, malondialdehyde, biochemical markers, immunoassay, controlled study, comparative study, laboratory rat, animal study

Jian-Ching Ren, Qianlong Zhu, Nancy LaPaglia, Nicholas V. Emanuele, and Mary Ann Emanuele.  Ethanol-induced alterations in Rab proteins: Possible implications for pituitary dysfunction.  Alcohol 35(2):103-112, February 2005.

Summary: Pubertal male rats exposed chronically to ethanol have decreased serum testosterone; increased gonadotropins, pituitary luteinizing hormone (LH), and follicle stimulating hormone (FSH) content; and decreased or inappropriately normal serum LH and FSH levels, suggesting impaired secretion of gonadotropins. The molecular mechanisms remain undefined, but disruption of vesicle-mediated secretory processes is possible because intracellular protein trafficking pathways are involved in secretion of glycoproteins such as FSH and LH. Because small guanosine triphosphate (GTP)-binding proteins of Rab family have been implicated as key regulators of membrane and protein trafficking in mammalian cells, this study examined whether ethanol-impaired pituitary FSH and LH secretion is associated with changes in Rab proteins, particularly Rab1B, Rab3B, Rab6, and Rab11. Male laboratory rats 35 days old were pair-fed a Lieber–DeCarli diet with ethanol or without ethanol for 5 to 60 days. Serum testosterone levels were decreased after ethanol exposure, while LH and FSH were inappropriately unchanged. Immunohistochemical staining showed decreased Rab1B, Rab3B, and Rab11 protein levels in ethanol-treated pituitaries. Immunoblotting showed that ethanol induced a transient reduction in Rab6 after 5 days of ethanol exposure, whereas Rab3B decreased after 20 days, Rab11 after 30 days, and Rab1B after 60 days. Despite these changes in Rab proteins, messenger ribonucleic acid (mRNA) levels were unaffected by ethanol exposure. Thus reductions in key Rab proteins may lead to altered vesicle trafficking and may play a role in disruption of pituitary FSH and LH secretion caused by ethanol. NIAAA Glossary Terms:  ethanol, testosterone, luteinizing hormone, follicle-stimulating hormone, chronic AODE, pituitary, glycoproteins, GTP-binding protein, laboratory rat, controlled study, comparative study, mRNA, immunoassay, animal study

Mariann R. Piano, Timothy M. Carrigan, and Dorie W. Schwertz.  Sex differences in ethanol liquid diet consumption in Sprague-Dawley rats.  Alcohol 35(2):113-118, February 2005.

Summary: Sex differences in ethanol consumption between different strains of male and female rats have been reported, but these differences have not been studied in rats of the Sprague-Dawley strain. This study therefore examined body growth, ethanol consumption (ml/day and g/kg/day, and blood ethanol levels (BELs) in adult male and female (n = 6–8 per group; sham-operated and ovariectomized) Sprague-Dawley rats consuming different concentrations (3% to 9% v/v) of the Lieber-DeCarli liquid ethanol diet. Throughout the study, male rats weighed significantly more than both female groups, and ovariectomized female rats weighed more than sham female rats. Ethanol diet consumption (ml/day) was significantly greater in males than in females at higher ethanol concentrations, but when the diet consumption was expressed in grams of ethanol/kg/day, the sham-operated female group was shown to consume significantly more ethanol than the male group. Even though there were differences in ethanol intake, blood ethanol levels were similar among the groups. The data indicate that, like other strains, Sprague-Dawley rats exhibit sex differences in their pattern of body growth (weight gain) and ethanol intake, but blood ethanol levels were similar among the groups. NIAAA Glossary Terms:  ethanol, AOD consumption, gender differences, animal strains, laboratory rat, BAC, controlled study, comparative study, ovary, operative surgery, body weight, animal study

Wendy N. Strother, William J. McBrideabc, Lawrence Lumeng, and Ting-Kai Li.  Effects of acute administration of ethanol on cerebral glucose utilization in adult alcohol-preferring and alcohol-nonpreferring rats,  Alcohol 35(2):119-128, February 2005.

Summary: The [14C]-2-deoxyglucose (2-DG) technique was used to examine local cerebral glucose utilization (LCGU) rates after acute ethanol administration in selected brain regions of alcohol-preferring (P) and alcohol-nonpreferring (NP) rats. Adult male P and NP rats were injected intraperitoneally with saline, 0.25 g/kg, or 1.0 g/kg ethanol 10 minutes before an intravenous bolus of [14C]2-DG (125 μCi/kg). Timed arterial blood samples were collected over 45 minutes and assayed for plasma glucose, ethanol, and [14C]2-DG levels. Image densities were determined by quantitative autoradiography and LCGU values calculated. Data were collected from several key limbic, basal ganglionic, cortical, and subcortical structures. Low-dose ethanol (0.25 g/kg) significantly decreased LCGU rates in several brain regions including the medial prefrontal cortex, olfactory tubercles, and the CA1 subregion of the hippocampus of P rats but had no significant effects on LCGU rates in the NP rats. Moderate-dose ethanol (1.0 g/kg) also significantly lowered LCGU rates in many brain regions of P rats, including key limbic structures, such as the medial prefrontal cortex, olfactory tubercles, ventral tegmental area, basolateral nucleus of the amygdala, lateral septum, and ventral pallidum. Moderate-dose ethanol also significantly lowered LCGU rates in the medial prefrontal cortex as well as in the habenula of NP rats. All other regions were unaffected in the NP rats. The results support the suggestion that certain central nervous system regions of P rats may be more sensitive than those of NP rats to the effects of low to intermediate doses of ethanol. NIAAA Glossary Terms:  ethanol, AOD consumption, animal selectively bred for alcohol preference, laboratory rat, controlled study, comparative study, central nervous system, cerebrum, glucose metabolism, cerebral cortex, limbic system,  basal ganglia, prefrontal cortex, olfactory system, hippocampus, ventral tegmental area, amygdala, radioactive chemical elements, carbon, animal model, animal study

Helen J.K. Sable, Zachary A. Rodd, Richard L. Bell, Jonathan A. Schultz, Larry Lumeng, and William J. McBride.  Effects of ethanol drinking on central nervous system functional activity of alcohol-preferring rats.  Alcohol 35(2):129-135, February 2005.

Summary: The [14C]-2-deoxyglucose (2-DG) technique was used to assess the rates of local cerebral glucose utilization (LCGU) in key limbic, cerebral cortical, hippocampal, basal ganglionic, and subcortical regions of alcohol-preferring (P) rats following chronic 24-hour free-choice ethanol drinking. Adult male P rats were submitted to either 8 continuous weeks of two-bottle access to 15% ethanol and water (E-C group); 8 weeks of identical two-bottle access followed by 2 weeks of ethanol deprivation (E-D group); cycles of 2 weeks of two-bottle ethanol access and 2 weeks of deprivation, repeated for four cycles (E-RD group); or water only treatment (ethanol-naive [E-N] group). A single pulse of [14C]-2-DG (125 μCi/kg) was administered through a venous catheter, and timed arterial blood samples were collected over 45 minutes and later assayed for plasma glucose and [14C]-2-DG concentrations. Quantitative autoradiography was used to determine 14C densities, and LCGU values were calculated. Except for a few small differences in the hippocampus, no significant differences were found in any of the central nervous system (CNS) regions examined among the four experimental groups of P rats. Animals in the E-D group had lower LCGU rates in the anterior hippocampal CA1 subregion than animals in the E-N, E-C, and E-RD groups. In the anterior hippocampal CA3 subregion and the anterior hippocampal dentate gyrus, the E-D group had significantly lower LCGU rates than the E-RD group. Overall, the results of this study indicate that 24-hour ethanol-drinking has little effect on CNS functional neuronal activity in P rats. NIAAA Glossary Terms:  ethanol, AOD consumption, animal selectively bred for alcohol preference, laboratory rat, animal model, glucose metabolism, central nervous system, limbic system, cerebral cortex, hippocampus, basal ganglia, radioactive chemical elements, radiography, carbon, controlled study, comparative study, animal study

Julie Broadbent, Kathryn M. Kampmueller, and Sharon A. Koonse.  Role of dopamine in behavioral sensitization to ethanol in DBA/2J mice.  Alcohol 35(2):137-148, February 2005.

Summary: It has been proposed that behavioral sensitization plays an important role in addiction. Elucidation of the neural processes mediating sensitization may therefore lead to the development of new pharmacotherapeutic treatments. Numerous studies have examined sensitization to psychostimulants and morphine, but despite the prevalence of alcoholism the neural processes underlying sensitization to ethanol have not been identified. This study examined the role of different components of the dopamine system in sensitization to the locomotor stimulant effects of ethanol in DBA/2J mice. Sensitization was induced by administering ethanol (2 g/kg) intraperitoneally before locomotor activity trials. Control groups received saline (12.5 ml/kg) intraperitoneally before each activity trial. The ability of the dopamine uptake inhibitors GBR 12909 (3.33–10.0 mg/kg) and bupropion (20 and 30 mg/kg) to cross-sensitize to ethanol was then examined. In addition, the effects of the dopamine D1 receptor agonist SKF 82958 (0.1–1.0 mg/kg), the dopamine D2/D3 agonist quinpirole (0.05 and 0.1 mg/kg), and a combination of SKF 82958 and quinpirole were examined. Cross-sensitization was observed between the dopamine uptake inhibitor GBR 12909 and ethanol, but bupropion, a less selective uptake inhibitor, did not exhibit cross-sensitization. Similarly, stimulation of D1 and D2/D3 receptors did not cause cross-sensitization even when the agonists were administered together. Collectively, these data suggest that sensitization to ethanol is associated with changes in the dopaminergic system. NIAAA Glossary Terms:  ethanol, AOD sensitivity, addiction, AOD dependence, intraperitoneal administration, dopamine, dopaminergic neuron, locomotion, controlled study, comparative study, laboratory mice, neurotransmitter uptake inhibitors, agonists, animal study

C.R. Goodlet.  Transitions, aims, and initiatives for Alcohol with the new editorship (Editorial).  Alcohol 35(1):1-2, January 2005.

(No abstract available.)

David M. Umulis, Nihat M. Gürmen, Prashant Singh, and H. Scott Fogler.  A physiologically based model for ethanol and acetaldehyde metabolism in human beings.  Alcohol 35(1):3-12, January 2005.

Summary: Pharmacokinetic models for ethanol metabolism have contributed to understanding ethanol clearance in human beings, but they fail to account for ethanol's metabolite, acetaldehyde. Acetaldehyde accumulation leads to toxic signs and symptoms, such as cardiac arrhythmias, nausea, anxiety, and facial flushing. Because determining the levels of acetaldehyde in blood or other tissues is difficult due to artifactual formation and other technical issues, the authors developed a physiologically based pharmacokinetic (PBPK) model that is an excellent match for existing ethanol and acetaldehyde concentration-time data. The model consists of five compartments that exchange material: stomach, gastrointestinal tract, liver, central fluid, and muscle. All compartments except the liver are modeled as stirred reactors. The liver is modeled as a tubular flow reactor. Average enzymatic rate laws were derived for alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), kinetic parameters were determined from the literature, and best-fit parameters were found by minimizing the squared error between the profiles and the experimental data. The model's transient output correlates strongly with the experimentally observed results for healthy individuals and for those with reduced ALDH activity caused by a genetic deficiency of the primary acetaldehyde-metabolizing enzyme ALDH2. The model also shows that the reverse reaction of acetaldehyde back into ethanol is essential and keeps acetaldehyde levels about one-tenth of what they would be if the reaction were irreversible. NIAAA Glossary Terms:  ethanol metabolism, acetaldehyde, pharmacokinetics, scientific model, stomach, gastrointestinal tract, liver, body fluid, muscle, enzymes, alcohol dehydrogenases, aldehyde dehydrogenases, aldehyde dehydrogenase isoenzyme, correlation analysis, biochemical reaction property, theoretical study

Blair U. Bradford and Ivan Rusyn.  Swift increase in alcohol metabolism (SIAM): Understanding the phenomenon of hypermetabolism in liver (Review).  Alcohol 35(1):13-17, January 2005.

Summary: Continuous exposure to ethanol is known to produce adaptive changes in liver alcohol and oxygen metabolism. A considerable burst of hepatic respiration can also occur after administration of a single large dose of ethanol and results in a near doubling of ethanol metabolism, high demand for oxygen, and downstream or pericentral hypoxia. The phenomenon is called the swift increase in alcohol metabolism (SIAM).These dramatic changes in rates of ethanol metabolism and tissue concentrations of oxygen are not due to induced enzyme activity in liver. They depend on activation of mitochondrial function, increased co-factor supply for nicotinamide adenine dinucleotide (NAD)-dependent alcohol metabolism, depletion of glycogen reserves, liberation of fatty acids through activation of an adrenergic response to ethanol providing substrate for catalase, and activation of Kupffer cells, the hepatic macrophages responsible for production of cytokines and prostaglandins. Understanding the mechanisms of hypermetabolism in liver can have vital ramifications for knowledge of both alcohol-related and alcohol-unrelated liver damage because hypoxia resulting from hypermetabolism can compound effects of pharmaceuticals and environmental agents on the liver. SIAM is an excellent example of the complexity of cell-cell interactions in liver and extrahepatic regulation of biochemical and molecular events in this organ. The authors anticipate consideration of this important phenomenon in studies of liver disease and biochemistry. NIAAA Glossary Terms:  ethanol metabolism, oxygen, hypoxia, mitochondria, NAD, glycogen, fatty acids, epinephrine, catalase, Kupffer cell, macrophage, cytokines, prostaglandins, AODR disorder, liver disorder, alcoholic liver disorder, drug therapy, environmental factors, biochemical mechanism, literature review

George Fein and Bennett Landman.  Treated and treatment-naive alcoholics come from different populations.  Alcohol 35(1):19-26, January 2005.

Summary: The presumption that associations found in studies of select samples of alcoholic apply to all alcoholics (including untreated alcoholics in the general population) is an example of Berkson's fallacy (defined as a spurious correlation between two diseases or between a disease and a risk factor arising from biased sampling). This study examined whether treated and untreated alcoholics have similar early alcohol use histories by comparing abstinent alcoholics (treated and sober at least 6 months) with treatment-naive alcoholics (active drinkers). The participants were 14 pairs of women and 25 pairs of men matched on the age at which they first met criteria for heavy alcohol use (80 drinks/month for women, 100 drinks/month for men). Retrospective alcohol use information was obtained by the timeline follow-back interview method. Alcohol dose and duration of use were subsequently computed for two intervals: (1) time between the first drink and the date at which the person met criteria for heavy drinking and (2) time between meeting criteria for heavy drinking and current age of the treatment-naive person from each pair. Alcohol dose did not differ between the two groups during the period before the matching “heavy drinking” criteria were met. After heavy alcohol use criteria were met, the treated alcoholics had higher average and peak alcohol doses than the treatment-naive alcoholics. This led to rejection of the hypothesis that the treatment-naive alcoholics and the treated alcoholics have similar alcohol use trajectories over time, with the treatment-naive sample simply being observed earlier in its alcohol use histories. The authors concluded instead that the two groups come from different alcohol-using populations. In fact, the treated alcoholics had alcohol doses more than 50% higher than those of treatment-naive alcoholics in the years just after they began drinking heavily. This finding supports the suggestion that results from studies of alcoholics in treatment or after treatment (i.e., most studies of alcoholics) cannot be generalized to untreated individuals (i.e., the majority of alcoholics. NIAAA Glossary Terms:  AOD dependence, AOD use pattern, heavy AOD use, AOD intake per occasion, treatment factors, treatment outcome, help-seeking behavior, hypothesis testing,  sampling bias, interview, retrospective study, patient AODU history, comparative study, human study

Giancarlo Colombo, Carla Lobina, Paola Maccioni, M. Francesca Mascia, Alessandro Orrù, Gian Luigi Gessa, and Mauro A.M. Carai.  Suppression of acquisition of alcohol-drinking behavior by the concurrent availability of saccharin in Sardinian alcohol-preferring (sP) rats.  Alcohol 35(1):27-33, January 2005.

Summary: The effect of concurrent presentation of saccharin on the acquisition of alcohol-drinking behavior was investigated in selectively bred Sardinian alcohol-preferring (sP) rats. Alcohol-naive rats were given access to saccharin (0%, 0.01%, 0.1%, 1%, or 3% w/v in water), alcohol (10% v/v in water), and water under the home cage, three-bottle, free-choice regimen, with unlimited access for 24 hours/day for 10 consecutive days. Intake of saccharin solution resulted as an inverted-U function of saccharin concentration, reaching polydipsic-like values at the 0.1% concentration. In contrast, alcohol intake was a U function of saccharin concentration, being virtually suppressed in the groups of rats exposed to the highly accepted 0.1% and 1% concentrations of saccharin. The results indicate that (1) the concurrent presentation of highly palatable solutions of saccharin suppresses acquisition of alcohol-drinking behavior in sP rats and (2) the suppressive effect of saccharin solutions on the acquisition of alcohol-drinking behavior in sP rats was positively related to their degree of acceptability. The authors hypothesize that immediate and continuous access to the highly palatable saccharin solution may have distracted the rat, preventing it from consuming the amounts of alcohol solution needed to disclose and experience the psychopharmacologic effects of alcohol on which alcohol-drinking behavior in sP rats is based. NIAAA Glossary Terms:  saccharin, ethanol, AOD use behavior, animal selectively bred for AOD preference, laboratory rat, dose-response relationship, animal study

Giancarlo Colombo, Carla Lobina, Paola Maccioni, M. Francesca Mascia, Alessandro Orrù, Gian Luigi Gessa, and Mauro A.M. Carai.  Suppression of maintenance of alcohol-drinking behavior by the concurrent availability of saccharin in Sardinian alcohol-preferring (sP) rats.  Alcohol 35(1):35-41, January 2005.

Summary: This study investigated the effect of the concurrent presentation of saccharin on the maintenance of alcohol-drinking behavior in selectively bred Sardinian alcohol-preferring (sP) rats. Rats were initially given access to alcohol (10% v/v in water) and water under the home cage, two-bottle, free-choice regimen, with unlimited access for 24 hours/day for 8 consecutive weeks. Next, a third bottle, containing saccharin (0%, 0.01%, 0.1%, 1%, or 3% w/v in water), was concomitantly offered for an additional 10 consecutive days. Saccharin solution intake was an inverted-U function of saccharin concentration, with the 0.1% saccharin solution having the highest acceptance. Alcohol intake was a U-shaped function of saccharin concentration, being reduced by 65%–95% in the group of rats exposed to the 0.1% saccharin solution. These results indicate that (1) the concurrent presentation of highly palatable solutions of saccharin markedly reduced alcohol intake in alcohol-experienced sP rats and (2) the reducing effect of saccharin solutions on the alcohol intake in sP rats was positively related to their degree of acceptability. The authors hypothesize that saccharin solutions may have functioned as a reinforcer, partially substituting for alcohol reinforcement and rendering alcohol drinking less urgent. NIAAA Glossary Terms:  saccharin, ethanol, AOD use behavior, animal selectively bred for AOD preference, laboratory rat, dose-response relationship, animal study

Arthur Tomie, Jennifer Gittleman, Erik Dranoff, and Larissa A. Pohorecky.  Social interaction opportunity and intermittent presentations of ethanol sipper tube induce ethanol drinking in rats.  Alcohol 35(1):43-55, January 2005.

Summary: The effects of social interaction opportunity (SIO) and intermittent presentations of the ethanol sipper tube (IS) on autoshaping of ethanol drinking were evaluated in nondeprived rats. Rats were assigned to one of seven groups. Two groups experienced brief IS presentation, either paired with or randomly related to the response-independent raising of a guillotine door (D) revealing the presence of a conspecific male rat in a holding cage (SIO). Two control groups received similar training except that the D revealed an empty cage, whereas a third control group received IS but neither D nor SIO. For two additional control groups, the ethanol sipper tube was continuously available during the session, with and without SIO, with both groups receiving intermittent D. In IS conditions, procedures with SIO induced more ethanol intake than non-SIO procedures did, indicating that SIO contributed to ethanol intake, but D procedures did not differ from non-D procedures, indicating that ethanol drinking was not related to the operation of the door. Groups that received training procedures providing for both SIO and IS showed more rapid initiation of ethanol intake and more rapid escalation of ethanol intake as the concentration of ethanol in the sipper tube conditioned stimulus was increased across sessions. Theoretical explanations based on cue at response manipulandum/autoshaping, schedule-induced polydipsia, incentive sensitization, and intermittency-induced arousal are considered. NIAAA Glossary Terms:  animal behavior, social behavior, ethanol, laboratory rat, controlled study, AOD intake per occasion, AOD use behavior, cue reactivity, animal study

Rukhsana Sultana, Bhupanapadu Sunkesula Solomon Raju, Varsha Sharma, Pallu Reddanna, and Phanithi Prakash Babu.  Formation of acetaldehyde adducts of glutathione S-transferase A3 in the liver of rats administered alcohol chronically.  Alcohol 35(1):57-66, January 2005.

Summary: Hepatic tissue damage induced by chronic ethanol exposure is mediated through acetaldehyde and associated with reactive oxygen species, which impair cellular defense mechanisms. Because glutathione S-transferases (GSTs) play an important role in the detoxification of xenobiotics and reactive oxygen species, this study tested the effect of ethanol administration on structural and functional characteristics of rat liver Alpha class GSTs (rGSTs). Western blot analysis revealed an appreciable change in the expression of rGSTA3 subunit levels, whereas no change was observed in activity after chronic alcohol treatment. Reverse-phase high performance liquid chromatographic analysis of rGSTs that were affinity purified with glutathione showed a 1.07-fold increase in rGSTA3 subunit levels in rats chronically treated with ethanol. In addition, liquid chromatographic-electrospray ionization mass spectrometric analysis of GSTs that were affinity purified with glutathione showed the formation of acetaldehyde adducts to the rGSTA3 subunit. Given the abundant expression of rGSTA3 subunit and acetaldehyde adduct formation, these results support the suggestion that modification of rGSTA3 subunit, thus impairing its function, in alcohol-exposed rats may contribute to the progression of alcohol-induced liver damage. NIAAA Glossary Terms:  alcoholic liver disorder, ethanol, acetaldehyde, oxygen radicals, free radicals, oxidative stress, glutathione S-transferases, xenobiotics, detoxification, Western blotting, gene expression, chronic AODE, high pressure liquid chromatography, adduct, spectrometry, disease course, laboratory rat, animal study

Cynthia A. Dlugos.  Analyses of smooth endoplasmic reticulum of cerebellar parallel fibers in aging, ethanol-fed rats.  Alcohol 35(1):67-73, January 2005.

Summary: The smooth endoplasmic reticulum (SER), a calcium storage organelle, is essential for normal neuronal function. Dilation of the SER is pathologic, a threat to neuronal calcium homeostasis, and has been reported within the dendrites of cerebellar Purkinje neurons of aging rats after lengthy ethanol treatment. This study investigated ethanol-related alterations of parallel fiber SER, which have not been studied despite the fact that such dilation may precede and contribute transsynaptically to SER dilation and degeneration in Purkinje neuron dendrites. Male Fischer 344 rats (N = 120; 12 months old) were randomly divided into three dietary groups (40 rats per group) and fed rat chow, the AIN-93M liquid control diet, or the AIN-93M liquid ethanol diet (without water) for 5, 10, 20, or 40 weeks (30 rats per time point). Sections from posterior vermal lobules were viewed with electron microscopy, and maximum and minimum diameters of parallel fiber SER profiles were measured. Ethanol-related dilation of parallel fiber SER was not found after 5, 10, 20, or 40 weeks of treatment, but age-related dilation of parallel fiber SER profiles did occur. The results support the suggestions that (1) parallel fiber SER, unlike the SER in Purkinje neurons, is insensitive to ethanol and (2) the mechanisms by which ethanol and aging alter cerebellar function and structure are different. NIAAA Glossary Terms:  endoplasmic reticulum, ethanol, chronic AODE, calcium metabolism disorder, homeostasis, neurotransmission, neuron, Purkinje cell, dendrite, cerebellum, laboratory rat, controlled study, age differences, animal study

Judit Garriga, Joaquim Fernández-Solá, Ester Adanero, Alvaro Urbano-Márquez, and Roser Cussó.  Metabolic effects of ethanol on primary cell cultures of rat skeletal muscle.  Alcohol 35(1):75-82, January 2005.

Summary: Glycogen accumulates in the skeletal muscles of individuals who have consumed ethanol chronically. Changes in the energy balance caused by ethanol consumption might lead to alcoholic myopathy. Experimental models used in the past, such as skeletal muscle biopsy samples of alcohol-dependent individuals or animals, do not distinguish between direct and indirect effects of ethanol (i.e., alterations to the nervous or endocrine system). This study evaluated the direct effect of ethanol on skeletal muscle glycogen concentrations and related glycolytic pathways. Changes in metabolite concentrations and enzyme activities of carbohydrate metabolism were measured in primary cell cultures of rat skeletal muscle exposed to ethanol for two periods. The concentrations of glycolytic metabolites and the activities of several enzymes that regulate glucose and glycogen metabolism were measured. After a short exposure to ethanol (6 hours), glucose metabolism slowed. Glycogen accumulation was observed after 48 hours of ethanol exposure. NIAAA Glossary Terms:  chronic AODE, ethanol, glycogen, skeletal muscle, AODR myopathy, nervous system, endocrine system, glycolysis, carbohydrate metabolism disorder, enzymes, glucose, cell culture study, laboratory rat, animal study

T.R. Jerrells.  Change of Editor-in-Chief for Alcohol (Editorial).  Alcohol 34(2):99-100, October 2004.

(No abstract available.)

John J. Woodward.  Fyn kinase does not reduce ethanol inhibition of zinc-insensitive NR2A-containing N-methyl-D-aspartate receptors.  Alcohol 34(2):101-105, October 2004.

Summary: Ethanol inhibits ion flux through N-methyl-D-aspartate (NMDA) receptors at concentrations that are associated with intoxicated behavior. NMDA receptor sensitivity to ethanol is influenced by subunit composition and interactions with cytoskeletal elements. Evidence supports the suggestion that the inhibitory effect of ethanol on NMDA receptors containing the NR1/2A subunit is reduced by tyrosine phosphorylation catalyzed by Fyn kinase. However, tyrosine kinases also reduce the high-affinity zinc sensitivity of NR1/2A receptors, suggesting that kinase-dependent effects on ethanol inhibition may be secondary to relief of zinc inhibition. The present study determined the effect of Fyn kinase on the ethanol inhibition of NR1/2A receptors under conditions in which zinc sensitivity is eliminated. Human embryonic kidney 293 (HEK 293) cells were transiently transfected with wild-type or mutant NMDA subunits, and glutamate-activated currents were measured using patch-clamp electrophysiology. Inclusion of a tyrosine phosphatase inhibitor in the recording pipette eliminated the potentiation of NR1/2A currents by heavy metal chelators. Under these conditions, Fyn kinase did not reduce ethanol inhibition of wild-type receptors and also had no effect on the magnitude of ethanol inhibition of zinc-insensitive NR1/2A(H128S) receptors. These results indicate that Fyn kinase does not directly affect the ethanol sensitivity of NR1/2A receptors. NIAAA Glossary Terms:  NMDA receptors, ethanol, ion, AOD intoxication, AODR behavioral problem, cytoskeleton, tyrosine, phosphorylation, tyrosine kinase, zinc, mutation, enzyme inhibitors, structure activity relationship, cell culture study, human study

Maria Cristina Caroleo, Nicola Costa, Paola Tirassa, and Luigi Aloe.  Nerve growth factor produced by activated human monocytes/macrophages is severely affected by ethanol.  Alcohol 34(2):107-114, October 2004.

Summary: Although the precise cellular target of ethanol's impairment of immune response remains unknown, several studies have shown that ethanol acts primarily by interfering with the ability of blood monocyte-derived macrophages to produce cytokines and growth factors. This study tested the hypothesis that exposure to ethanol would affect the synthesis of nerve growth factor (NGF) as well as expression of NGF receptor trkA in monocytes/macrophages, because NGF is known to play a key role in responses mediated by this cell population. Because NGF has been reported to affect the synthesis of proinflammatory cytokines, the study also evaluated whether the production of tumor necrosis factor-alpha (TNF-α) would be affected by ethanol-mediated changes in NGF synthesis. The results showed that acute exposure of lipopolysaccharide-activated human monocyte/macrophage cultures to ethanol resulted in a sharp decrease in endogenously-produced NGF, which was associated with reduced expression of high-affinity NGF receptors on cell membranes and impaired production of TNF-α. These findings support the suggestion of a new mechanism by which ethanol can compromise the efficiency of the mononuclear phagocyte system in dealing with infection and host inflammatory response. NIAAA Glossary Terms:  immune response, ethanol, monocyte, macrophage, cytokines, nerve growth factors, receptors, inflammation, cytokines, tumor necrosis factor-alpha, lipopolysaccharide, cell culture study, phagocyte, infection, human study

Soon Ae Kim, Jong-Woo Kim, Ji-Young Song, Sunny Park, Hee Jae Lee, and Joo-Ho Chung.  Association of polymorphisms in nicotinic acetylcholine receptor α₄ subunit gene (CHRNA4), μ- µ-opioid receptor gene (OPRM1), and ethanol-metabolizing enzyme genes with alcoholism in Korean patients.  Alcohol 34(2):115-120, October 2004.

Summary: Findings from several studies indicate that ethanol enhances the activity of α4β2 neuronal nicotinic acetylcholine receptor and support the possibility that a polymorphism of the nicotinic acetylcholine receptor α4 subunit gene (CHRNA4) modulates enhancement of nicotinic receptor function by ethanol. To identify the association between the CfoI polymorphism of the CHRNA4 and alcoholism, the authors examined distribution of genotypes and allele frequencies in Korean patients diagnosed with alcoholism (n = 127) and Korean control subjects without alcoholism (n = 185) with polymerase chain reaction–restriction fragment length polymorphism methods. They detected an association between the CfoI polymorphism of the CHRNA4 and alcoholism in Korean patients (genotype p = 0.023; allele frequency p = 0.047). The genotypes and allele frequencies of known polymorphisms in other alcoholism candidate genes, such as alcohol metabolism-related genes [alcohol dehydrogenase 2 (ADH2), aldehyde dehydrogenase 2 (ALDH2), alcohol dehydrogenase 3 (ADH3), and cytochrome P450 2E1 (CYP2E1)] and μ-opioid receptor gene (OPRM1), were studied. The polymorphisms of ADH2, ALDH2, and CYP2E1 were significantly different in alcoholic patients and control subjects without alcoholism, but ADH3 and OPRM1 did not differ between the two groups. NIAAA Glossary Terms:  ethanol, nicotinic receptor, cholinergic receptors, genetic polymorphism, genotype, allele, gene frequency, genetic trait, South Korea, AOD dependence, controlled study, polymerase chain reaction, alcohol dehydrogenases, aldehyde dehydrogenases, cytochrome P450 2E1, mu-opioid receptors, human study

Alexandr Parlesak, Michael Hans-Ulrich Billinger, Christian Schäfer, Heinz-Dieter Wehner, Christiane Bode, and Johann Christian Bode.  First-pass metabolism of ethanol in human beings: Effect of intravenous infusion of fructose.  Alcohol 34(2):121-125, October 2004.

Summary: Intravenous infusion of fructose has been shown to increase ethanol metabolism by enhancing the reoxidation of reduced nicotinamide adenine dinucleotide (NADH+). The present study investigated the effect of fructose infusion on first-pass ethanol metabolism in human volunteers. First-pass ethanol metabolism was significantly higher after fructose administration compared with findings for control experiments with an equimolar dose of glucose. Fructose is metabolized predominantly in the liver and presumably has virtually no effects in the stomach. Therefore the results of this study support the assumption that the stomach is the site of only a negligible part of first-pass ethanol metabolism. NIAAA Glossary Terms:  fructose, ethanol metabolism, oxidation-reduction, glucose, intravenous administration, controlled study, liver, stomach, human study

Vanessa Jimenez, Daniel P. Cardinali, Pilar Cano, María P. Alvarez, Carlos F. Reyes Toso, and Ana I. Esquifino.  Effect of ethanol on 24-hour hormonal changes in peripubertal male rats.  Alcohol 34(2):127-132, October 2004.

Summary: The effect of chronic (4 weeks) ethanol feeding on 24-hour variation of pituitary-testicular function was analyzed in peripubertal male Wistar rats by measuring circulating concentrations of prolactin (PL), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (TS), and thyrotropin (TT). Animals were maintained under a 12-hour light,12-hour dark photoperiod and received a liquid diet for 4 weeks, starting on day 35 of life. The ethanol-fed group received a diet similar to that provided to control animals, except that maltose was replaced isocalorically with ethanol (36% of calories). Rats were killed at one of six times around the clock, beginning at zeitgeber time (ZT) 1 (ZT 0=lights on). In ethanol-fed rats PL secretion was augmented, whereas secretion of FSH, LH, TS, and TT was decreased. Significant changes in the 24-hour secretory pattern of circulating hormones occurred in ethanol-fed rats, including the appearance of two peaks (at ZT 1 and ZT 9), rather than one peak, of FSH during the inactive phase of the daily cycle, suppression of the maximum plasma LH concentration during the first part of the inactive phase, and appearance of a second peak of TS and PL during the second part of the inactive phase (at ZT 5 and ZT 9, respectively) and of a second peak of plasma TT during the first part of the active phase (at ZT 13). The significant positive correlation between TS and individual LH and PL concentrations in control animals was no longer observed after ethanol administration. Chronic ethanol administration presumably affects the endogenous clock that modulates the circadian variation of the pituitary-gonadal axis and TT release in growing male rats. NIAAA Glossary Terms:  hypothalamic-pituitary-gonadal axis, male, testicles, ethanol, chronic AODE, sex hormones, prolactin, follicle-stimulating hormone, luteinizing hormone, testosterone, thyrotropin, plasma, circadian rhythm, controlled study, laboratory rat, animal study

James M. Bjork, Daniel W. Hommer, Steven J. Grant, and Cinnamon Danube.  Impulsivity in abstinent alcohol-dependent patients: Relation to control subjects and type 1–/type 2–like traits.  Alcohol 34(2):133-150, October 2004.

Summary: Behavior control problems in childhood has been linked to risk for alcoholism, but impulsivity in alcohol-dependent adults has not been well characterized. The present study used a variety of laboratory measures of impulsivity to assess whether detoxified alcohol-dependent patients (ADP; n = 130] were more impulsive than control subjects (CS; n = 41). In comparison with CS, ADP demonstrated (1) increased rates of commission errors, but not omission errors, in a continuous performance test, (2) a more severe devaluation of delayed reward, (3) increased rates of risky responses in a new risk-taking paradigm, and (4) higher psychometric scores of impulsivity and aggression. Across all subjects, aggressiveness correlated significantly with severity of delay discounting. A post hoc analysis of data obtained for male ADP indicated, in comparison with patients with late onset of problem drinking and no problem-drinking parent, that ADP with earlier age of problem drinking onset who also reported a problem-drinking father (type 2-like alcohol dependence) demonstrated faster response latencies and more responses to non-target stimuli (commission errors) in the continuous performance test, as well as higher psychometric aggression. In contrast, these subtypes of male ADP did not differ in delay discounting and risk taking. These findings collectively indicate that, compared with CS, ADP are more impulsive in several dimensions, with elevated impulsivity in a working memory task as well as aggressivity characteristic of alcohol-dependent men with type 2–like features. NIAAA Glossary Terms:  AOD dependence, risk factors, adult, impulsive behavior,  psychological performance test, risk-taking behavior, aggressive behavior, early AODU onset, parental alcoholism, controlled study, human study

Bhupendra S. Kaphalia, Ping Cai, M. Firoze Khan, Anthony O. Okorodudu, and G.A.S. Ansari.  Fatty acid ethyl esters: Markers of alcohol abuse and alcoholism.  Alcohol 34(2):151-158, October 2004.

Summary: At this time there are no reliable biomarkers of the diseases induced by chronic alcohol abuse or of alcoholism itself. This study measured plasma concentrations of fatty acid ethyl esters (FAEEs), which are nonoxidative metabolites of ethanol, in patients with detectable blood alcohol and examined the relation of plasma FAEE concentration to blood alcohol concentration (BAC). Of the 39 patients who were studied, only 5 had a history of chronic alcohol abuse and 6 had a history of acute alcohol abuse. Patients' ages ranged from 25 to 71 years. Higher FAEE concentrations were found in plasma from patients in the 41- to 50-year age group. There were no sex-related differences in BAC or FAEE concentrations. BAC exceeded 300 mg% in 13 patients and ranged between 200 mg% and 299 mg% in 11 and between 100 mg% and 199 mg% in 12. FAEE concentrations were approximately twofold higher in patients with a BAC greater than 300 mg%, compared with patients with a BAC between 100 mg% and 200 mg%. In most patients the main FAEEs detected were ethyl palmitate and ethyl oleate. In general, FAEE concentrations increased with increasing BAC. However, compared with patients with a history of acute alcohol abuse, increase in total FAEE concentrations was greater in patients with a history of chronic alcohol abuse (4,250 ng/ml and 15,086 ng/ml respectively). Fatty acid ethyl esters were in trace amounts or undetectable in the plasma of control subjects with no known alcohol ingestion. The findings support the hypothesis that nonoxidative metabolism to FAEEs is an important pathway of ethanol disposition during chronic alcohol abuse, and that FAEE concentrations can be a more reliable biomarker of chronic alcohol abuse than a history of acute alcohol abuse. NIAAA Glossary Terms:  AODR biochemical markers, AODR biological makers, fatty acid ethyl esters, ethanol metabolism, BAC, chronic AODE, acute AODE, AOD abuse, evaluation study, comparative study, human study

Francis X. Brennan and Michael F. Stromberg.  Ethanol consumption improves avoidance learning in rats: Role of deprivation interval.  Alcohol 34(2):159-164, October 2004.

Summary Studies using voluntary oral self-administration of ethanol in rats to model ethanol consumption and abuse in human beings have yielded contradictory results. This study assessed the effect of voluntary ethanol consumption on acquisition of a lever press escape/avoidance task in rats. Male Wistar rats were exposed to ethanol in a limited-access procedure, and either 1 day or 10 days after their last ethanol exposure were given a 4-hour lever press escape/avoidance session. Control animals were not exposed to ethanol at any time. Animals in the 1-day ethanol-deprivation group performed significantly better in avoidance responding than the controls or the 10-day ethanol-deprivation group. There were no group differences in number of lever presses during a safety period, a measure of anxiety. There was a significant negative correlation between behavioral performance and change in ethanol consumption after the escape/avoidance session, as well as a significant positive correlation between baseline ethanol consumption and avoidance performance. The findings are discussed in terms of the potential neural mediators of the improved avoidance effect in animals in the 1-day ethanol-deprivation group. NIAAA Glossary Terms:  ethanol, self administration of drugs, animal behavior, laboratory rat, harm-avoidance behavior, anxiety, correlation analysis, AOD consumption, controlled study, animal study

Keith L. Shelton.  Substitution profiles of N-methyl-d-aspartate antagonists in ethanol-discriminating inbred mice.  Alcohol 34(2):165-175, October 2004.

Summary: This study examined whether C57BL/6J (B6) and DBA/2J (D2) inbred mice differ in their expression of the N-methyl-D-aspartate (NMDA) receptor-mediated component of the discriminative stimulus effects of ethanol. Mice of both strains were trained to discriminate ethanol (1.5 g/kg intraperitoneally) from saline in a two-choice, milk-reinforced operant procedure. After completion of training, substitution and response rate dose-effect curves were generated for ethanol, the uncompetitive NMDA antagonists phencyclidine and ketamine, and the competitive NMDA antagonist d-CPPene. Dose-effect curves were also generated for midazolam, cocaine, m-chlorophenylpiperazine (mCPP), morphine, and gamma-hydroxybutyric acid (GHB). B6 and D2 mice learned the ethanol-versus-saline discrimination. Nearly full substitution for ethanol was produced by phencylidine in both strains, whereas ketamine fully substituted for ethanol only in B6 mice. d-CPPene partially substituted for ethanol in both strains. Moderate doses of phencyclidine produced greater response rate-increasing effects in B6 mice than in D2 mice, and high doses of phencyclidine were more potent for suppressing response rates in D2 mice. In contrast, d-CPPene had similar response rate-increasing effects in both strains, but high doses produced more potent response rate-decreasing effects in B6 mice. Among the other drugs tested, only midazolam produced substantial substitution for ethanol. The findings in this study seem to indicate that the behavioral effects of NMDA antagonists differ between strains, but that the NMDA-mediated component of the discriminative stimulus effects of ethanol is similar in B6 and D2 mice. NIAAA Glossary Terms:  NMDA receptors, ethanol, animal strains, laboratory mice,  comparative study, discrimination learning, antagonists, phencyclidine, ketamine, midazolam, cocaine, morphine, gamma-hydroxybutyric acid, dose-response relationship, animal study

David A. Blizard, David J. Vandenbergh, Akilah L. Jefferson, Cynthia D. Chatlos, George P. Vogler, and Gerald E. McClearn.  Effects of periadolescent ethanol exposure on alcohol preference in two BALB substrains.  Alcohol 34(2):177-185, October 2004.

Summary: Individual differences in response to ethanol were explored by comparing the effects of periadolescent ethanol exposure on ethanol drinking in a mouse model. From the 6th through the 12th week of age, males and females of two BALB mouse substrains were exposed to ethanol in one of three ways -- choice (water vs. 10% v/v ethanol), forced (10% ethanol in a single bottle), or gradual (single bottle exposure, starting with 0.5% ethanol and increasing at 2-day intervals to 10% ethanol). Immediately thereafter the mice were administered two-bottle ethanol preference tests (10% ethanol vs. water) for 15 days. All three kinds of exposure increased ethanol preference in male and female BALB/cByJ mice, compared with ethanol-naive controls. Only gradual ethanol exposure increased ethanol preference in BALB/cJ mice. During extended ethanol preference testing (39 days) in the gradual exposure group, the higher ethanol preference of tBALB/cByJ males persisted, but ethanol preference of female control mice in this strain — formerly ethanol naive, but at this point having received 10% ethanol in the two-bottle paradigm for 15 days — rose to the level of ethanol preference of females in the gradual exposure group, demonstrating that both adolescent and adult ethanol exposure stimulated ethanol preference in females of this strain. Across days of testing in adulthood, ethanol preference of the gradual ethanol-exposed BALB/cJ mice decreased, resulting in a lack of effect of gradual exposure to ethanol on ethanol preference in both males and females of this strain during extended testing. These strain differences support a genetic basis for the effects of ethanol exposure on alcohol preference. Exploration of the mechanisms underlying this gene-environment interaction in a mouse model may help elucidate individual differences in the effects of ethanol exposure in humans and contribute to understanding the causes of alcoholism. NIAAA Glossary Terms:  individual differences, animal strains, laboratory mice, ethanol, controlled study, gender differences, genetic trait, causal model, animal study

Craig J. Slawecki, Jennifer D. Thomas, Edward P. Riley, and Cindy L. Ehlers.  Neurophysiologic consequences of neonatal ethanol exposure in the rat.  Alcohol 34(2):187-196, October 2004.

Summary: Many of the neurotoxic and neurobehavioral consequences of neonatal ethanol exposure in rats have been characterized, but few studies have assessed neurophysiologic function in adult rats that were exposed to ethanol during neonatal development. This study examined the effects of neonatal ethanol exposure on adult electroencephalographic (EEG) activity and auditory event-related potentials (ERPs) in male Sprague-Dawley rats that were exposed to ethanol at 6.0 g/kg/day between postnatal days 4 through 9 by using an artificial-rearing procedure. There were two control groups: suckle controls (SC) and gastrostomized controls (GC). After reaching adulthood (3.5–4 months old), recording electrodes were implanted into the brain of each rat for assessment of EEG activity and of auditory ERPs from the cortex and hippocampus. Adult rats neonatally exposed to ethanol were hyperactive. EEG assessment revealed that ethanol exposure increased peak frequency in the frontal cortical and parietal cortical 16–32 Hz frequency bands. ERP assessment revealed reduced parietal cortical N1 amplitude in ethanol-exposed rats. Furthermore, parietal cortical N1 latency was increased in the GC group. These findings demonstrate that enhanced motor activity in rats exposed to ethanol during neonatal development occurs in combination with EEG indices of enhanced cortical and hippocampal arousal. The deficiency in cortical N1 amplitude indicates possible attention deficits. Overall, the findings indicate that neonatal ethanol exposure has enduring neurobehavioral consequences. This neurobehavioral profile in the rat is consistent with clinical observations of attention deficits and hyperactivity in children prenatally exposed to ethanol. NIAAA Glossary Terms:  ethanol, postnatal alcohol exposure, AODR neonatal disorder, electroencephalography, auditory perception, evoked potential, brain waves, cerebral cortex, hippocampus, attention deficit disorder, hyperactive behavior, attention deficit disorder with hyperactivity, child, prenatal alcohol exposure, controlled study, laboratory rat, animal study

Carmen A. Carrillo, Sarah F. Leibowitz, Olga Karatayev, and Bartley G. Hoebel.  A high-fat meal or injection of lipids stimulates ethanol intake.  Alcohol 34(2):197-202, October 2004.

Summary: Findings of earlier studies support a possible relation between dietary fat and ethanol intake, but it is unclear whether acute exposure to fat can increase ethanol consumption directly. This study examined whether daily overeating of fat, a single high-fat meal, or injection of fat can increase ethanol intake in rats. In Experiment 1, adult Sprague-Dawley rats were maintained on a high-fat diet (50% fat) for 7 days and switched subsequently to laboratory chow diet while being trained to drink 9% ethanol. Rats that had eaten the greatest amount of the high-fat diet subsequently drank the most ethanol. In Experiment 2, a 1-hour meal of the high-fat diet (50% fat) produced a significant increase in 7% ethanol consumption in comparison with the results of consuming an equicaloric, low-fat (10% fat) meal. In Experiment 3, the orosensory effect of fat was eliminated with an intraperitoneal injection of Intralipid, a fat emulsion (20% fat, 5.0 ml). Intralipid injection, in comparison with saline, increased the ingestion of 9% ethanol, in contrast to the effect injecting an equicaloric 50% glucose solution, which suppressed ethanol intake. These findings provide new evidence to support a positive relation between dietary fat and ethanol consumption. NIAAA Glossary Terms:  ethanol, AOD intake per occasion, AOD consumption, dietary fats, laboratory rat, comparative study, controlled study, animal study

Nicole M. Avena, Carmen A. Carrillo, Lance Needham, Sarah F. Leibowitz, and Bartley G. Hoebela.  Sugar-dependent rats show enhanced intake of unsweetened ethanol.  Alcohol 34(2):203-209, October 2004.

Summary: Rats show signs of dependence on sugar when it is available intermittently. The signs include binge consumption, withdrawal effects, and cross-sensitization with amphetamine. This study investigated whether sugar-dependent rats would show increased intake of unsweetened ethanol and, conversely, whether intermittent access to ethanol would augment sugar consumption. In Experiment 1, with intermittent versus ad libitum access to ethanol, Sprague-Dawley rats were given increasing concentrations of ethanol (1%, 2%, 4%, 7%, and 9%) over the course of 20 days. Rats in the intermittent ethanol access group, with 12-hour daily access, consumed more 4%, 7%, and 9% ethanol during the first hour of access, and more 9% ethanol daily, compared to rats given ad libitum access to ethanol. In Experiment 2, with ethanol as a gateway to sugar intake, the rats from Experiment 1 were switched to 10% sucrose with 12-hour daily access for 1 week. Rats in the intermittent ethanol access group consumed significantly more sugar than rats in a control group with no prior ethanol experience. In Experiment 3, with sugar as a gateway to ethanol to determine whether sugar dependence leads to increased ethanol intake, rats were maintained for 21 days in one of four groups: intermittent access to sugar and chow, ad libitum access to sugar and chow, intermittent access to chow, or ad libitum access to chow. Four days later, all groups were switched to intermittent ethanol access, as described in Experiment 1. The group with intermittent access to sugar and chow consumed the most 9% ethanol, supporting the suggestion that sugar dependence alters a rat's proclivity to drink ethanol. These results may relate to the comorbidity between binge-eating disorders and alcohol intake and the tendency of people abstaining from alcohol to consume excessive amounts of sugar. In conclusion, binge consumption of either ethanol or sugar promotes consumption of the other. NIAAA Glossary Terms:  sucrose, ethanol, cross-dependence, AOD consumption, AOD intake per occasion, binge AOD use, controlled study, laboratory rat, comorbidity, eating disorder, animal study

Thomas Hillemacher, Udo Reulbach, Kristina Bayerlein, Julia Wilhelm, Dominikus Bönsch, Wolfgang Sperling, Johannes Kornhuber, and Stefan Bleich,  Plasma homocysteine concentrations do not influence craving in alcohol withdrawal.  Alcohol 34(2):211-215, October 2004.

Summary: A number of studies have indicated that the glutamate system, especially the N-methyl-D-aspartate (NMDA) receptor, has a major function in alcoholism, including craving. Homocysteine (HCys) and other excitatory amino acids, such as glutamate and aspartate, lead to an overstimulation of NMDA receptors. Because alcoholism is associated with elevated plasma HCys concentrations, this study examined whether elevated plasma HCys concentrations influence craving in alcohol withdrawal. Two groups of patients with a diagnosis of alcohol dependence were compared. Group A (n = 50) comprised consecutively admitted patients who had been abstinent from alcohol 24-72 hours before admission for withdrawal treatment. Group B (n = 146) comprised consecutively admitted patients who were acutely intoxicated on admission. All patients were assessed with the Obsessive Compulsive Drinking Scale (OCDS) on the day of admission and after 7 days of treatment. The Mann-Whitney U test revealed that mean plasma homocysteine concentration was significantly higher in group B than in group A (27.1, SD 18.4 vs. 12.5, SD 5.3; p < 0.001). HCys concentration had no significant association with the extent of craving in either group, as shown by Spearman correlation (day 0: group A, r = −0.076, p = 0.601; group B, r = 0.120; p = 0.148) and logistic regression analysis. Although HCys is a potent modulator of glutamatergic neurotransmission, these results provide no evidence that it has pathophysiologic role in withdrawal craving. NIAAA Glossary Terms:  NMDA receptors, AOD dependence, AOD craving, AOD withdrawal syndrome, AOD abstinence, AOD intoxication, glutamate, aspartate, excitatory neurotransmitters, comparative study, psychiatric status rating scales, obsessive-compulsive disorder, correlation analysis, regression analysis, human study

Xin-Sheng Deng, Pequita Bludeau, and Richard A. Deitrich.  Formation of ethyl nitrite in vivo after ethanol administration.  Alcohol 34(2):217-223, October 2004.

Summary: The purpose was to determine whether ethyl nitrite, a new metabolite of ethanol in vivo, could be detected in vitro from the reaction of ethanol with peroxynitrite, as well as after administration of ethanol to mice. Ethyl nitrite analyte was determined by gas chromatography-mass spectrometry with headspace analysis using a solid-phase microextraction device. Peroxynitrite was allowed to react with ethanol under a variety of conditions in vitro. Ethyl nitrite was generated when peroxynitrite was allowed to react with ethanol. Male, inbred short-sleep mice were injected intraperitoneally with either ethanol (5.2 g/kg; 15.0% w/v ethanol in saline) or a 50:50 mixture of deuterium-labeled ethanol (D5-ethanol) and unlabeled ethanol. Blood samples and sections of whole brain and liver were obtained from mice 30 minutes later for determination of ethanol, D5-ethanol, ethyl nitrite, and deuterium-labeled ethyl nitrite (D5-ethyl nitrite). Time courses for the appearance of ethyl nitrite in blood samples and in whole brain and liver sections were determined. After ethanol administration, ethyl nitrite was detected and quantitated in blood, brain, and liver. A small fraction of ethyl nitrite was present. When the 50:50 mixture of labeled and unlabeled ethanol was administered, both ethyl nitrite and D5-ethyl nitrite were found in blood and brain in approximately the same ratio as that of ethanol and D5-ethanol. In liver, the level of D5-ethyl nitrite was more than twice that of ethyl nitrite, indicating a possible isotope effect in ethyl nitrite metabolism. The mechanism of ethyl nitrite formation is most likely the reaction of ethanol with peroxynitrite generated in vivo from nitric oxide. NIAAA Glossary Terms:  ethanol metabolism, nitrites, gas chromatography, spectrometry, peroxide, laboratory mice, selective breeding, deuterium, brain, liver, blood, nitric oxide, in vivo study, animal study

Masahiro Hayashi, Tsutomu Bandoh, Daiki Ushizawa, Shinya Takada, and Katsuji Hoshi.  Effects of acute and short-term administration of tryptophan plus ethanol on noradrenaline and serotonin metabolites in the locus coeruleus.  Alcohol 34(2):225-232, October 2004.

Summary: The effects of acute and short-term administration of tryptophan (TRYP) or TRYP plus ethanol on serotonin (5-hydroxytryptamine [5-HT]) and two of its metabolites, 5-hydroxyindoleacetic acid (5-HIAA) and 5-hydroxytryptophol (5-HTPL), in the locus coeruleus (LC) were investigated in rats by the microdialysis method. The acute effects of these drugs on noradrenaline and its metabolite 4-hydroxy-3-methoxymandelic acid (HMMA) were also addressed. A single intraperitoneal administration of TRYP (50 mg/kg) with ethanol (1.25 g/kg) did not change the concentrations of either noradrenaline or its metabolite in the LC. In contrast, administration of TRYP (50 mg/kg, i.p.) for 3 consecutive days caused an increase in the concentration of 5-HIAA, but not that of 5-HT, in the LC. Combined administration of TRYP plus ethanol for 3 days resulted in marked increases in 5-HIAA, but not 5-HTPL, in the LC. However, administration of ethanol (1.25 g/kg) for 3 days had no effect on the concentrations of 5-HT and its metabolites. The increased 5-HIAA concentration that resulted with combined TRYP plus ethanol administration was remarkably suppressed by disulfiram. Moreover, in comparison with TRYP-treated rats, teeth-chattering behavior was significant in rats treated with TRYP plus ethanol, but the enhancement of behavioral signs with combined treatment was markedly suppressed by disulfiram. These results seem to indicate that the stimulation of 5-HT metabolism in LC serotonergic neurons by TRYP was enhanced by the simultaneous administration of ethanol in short-term experiments, and that the increased 5-HIAA levels in the LC are responsible for behavioral activation. NIAAA Glossary Terms:  tryptophan, ethanol, serotonin, hydroxyindoleacetic acid, hydroxytryptophol, neurotransmitter metabolism, microdialysis, norepinephrine, brain, animal behavior, laboratory rat, disulfiram, animal study

Vinicius C. Carrard, Manoel Sant'Ana Filho, Pantelis V. Rados, Anna Cecília M. Chaves, and Isabel da Silva Lauxen.  Quantification of silver-staining nucleolar organizer region in epithelial cells of tongue of mice after exposure to, or intake of, alcohol.  Alcohol 34(2):233-238, October 2004.

Summary: The effect of ethanol on the proliferative activity of epithelial cells in the lingual mucosa of mice was evaluated by means of silver-staining nucleolar organizer region (AgNOR) count and area measurements. CF1 mice (N = 48) were divided into three groups. The test groups were submitted to topical exposure to, or intake of, 40% v/v ethanol. Biopsy specimens were collected from the middle third of the dorsal tongue at 0, 6, and 12 months, and samples were stained according to the AgNOR technique. Mean number and mean area of AgNOR per nucleus were calculated for 50 basal layer cells and 50 intermediate layer cells. Increases in mean number and mean area of AgNOR per nucleus in intermediate cells were observed at 12 months in the ethanol group (p < 0.05). Results showed that intake of 40% ethanol increased epithelial cell proliferation in the dorsal surface of lingual mucosa. NIAAA Glossary Terms:  ethanol,  epithelial cell, mouth, cell function, cell organelle, cell nucleus, biopsy, laboratory mice, evaluation, animal study

Anna Larsson, Elisabet Jerlhag, Lennart Svensson, Bo Söderpalm, and Jörgen A. Engel.  Is an α-conotoxin MII–sensitive mechanism involved in the neurochemical, stimulatory, and rewarding effects of ethanol?  Alcohol 34(2):239-250, October 2004.

Summary: A large body of evidence from epidemiologic and preclinical studies indicates that there is a positive correlation between intake of alcohol and nicotine. Studies from the authors' research group have demonstrated that nicotinic acetylcholine receptors, especially those located in the ventral tegmental area (VTA), are important for the stimulatory, rewarding, and dopamine-enhancing effects of ethanol. Furthermore, recent studies indicate that the α4β2∗ and the α7∗ receptor subunits of the nicotinic acetylcholine receptors do not appear to be involved in the neurochemical and behavioral effects of ethanol in rodents. The aim of the present study was to investigate further the role of different nicotinic acetylcholine receptor subunits in the stimulatory, dopamine-enhancing, and rewarding effects of ethanol in mice and rats by administering the peptide α-conotoxin MII (5 nmol), an antagonist of the α3β2∗, β3∗, and α6∗ subunits of the nicotinic acetylcholine receptor, locally into the VTA. A significant reduction of ethanol-induced accumbal dopamine overflow, measured using in vivo microdialysis, and of locomotor stimulation was observed in mice. Furthermore, α-conotoxin MII reduced voluntary ethanol intake significantly in both mice and rats. These results indicate that α-conotoxin MII-sensitive receptors may be important in mediating the stimulatory, dopamine-enhancing, and rewarding effects of ethanol, and that receptors sensitive to α-conotoxin MII may be targets for development of new adjuvant for treatment of ethanol dependence. NIAAA Glossary Terms:  ethanol, nicotine, cholinergic receptors, nicotinic receptors, ventral tegmental area, brain, dopamine, CNS stimulant, brain reward pathway, laboratory mice, laboratory rat, antagonists, peptides, locomotion, animal study

Yuri A. Blednov, Danielle Walker, Elizabeth Osterndorf-Kahanek, and R. Adron Harris.  Mice lacking metabotropic glutamate receptor 4 do not show the motor stimulatory effect of ethanol.  Alcohol 34(2):251-259, October 2004.

Summary: Group III metabotropic glutamate receptors (mGluRs), specifically receptors 4, 6, 7, and 8 (i.e., mGluR4, mGluR6, mGluR7, mGluR8), play an important role in the generation of locomotion as well as in the behavioral effects of some psychostimulants. Because the arousing or stimulant effects of ethanol seem to be relevant behavioral traits associated with its rewarding properties and genetic susceptibility to alcoholism, this study addressed the role of mGluR4 by studying behavioral actions of ethanol in mutant mice lacking mGluR4. Null mutant mice showed higher motor response to novelty than wild-type mice. Ethanol (1.0–2.5 g/kg) stimulated motor activity of wild-type mice, but not of null mutant mice. There were no significant differences between wild-type and knockout strains in ethanol consumption or preference in the two-bottle paradigm, severity of ethanol-induced acute withdrawal, or duration of loss of righting reflex. These results show that mGluR4 may play a role in locomotor activity in general and also display specificity for mediation of the motor stimulant effect of ethanol. Consistent with findings of other studies, these results confirm the lack of correlation between ethanol-induced motor stimulation and ethanol consumption measured in a self-administration paradigm in mice. NIAAA Glossary Terms:  ethanol, glutamate receptors, locomotion, psychoactive substances, CNS stimulant, AODR behavioral markers, animal behavior, laboratory mice, mutation, comparative study, controlled study, righting reflex, AOD consumption, self-administration, genetic theory of AODU, animal study

William M. Doyon, Vorani Ramachandra, Herman H. Samson, Cristine L. Czachowski, and Rueben A. Gonzales.  Accumbal dopamine concentration during operant self-administration of a sucrose or a novel sucrose with ethanol solution.  Alcohol 34(2):261-271, October 2004.

Summary: The objective was to determine the effect of operant self-administration of (1) 10% sucrose and (2) a first-time solution of 10% sucrose plus 5% or 10% ethanol, on dopamine (DA) concentration in the nucleus accumbens (NA). The operant procedure distinguished lever pressing (an appetitive behavior) from drinking for better assessment of the effect of fluid consumption on DA activity in the NA. Male Long-Evans rats were trained to bar press by using 10% sucrose reinforcement, and were required to make an escalating number of bar presses across daily sessions. Completion of the response requirement resulted in 20 minutes of access to the solution. Microdialysis samples were collected before, during, and after bar pressing and drinking, and content of ethanol and DA was determined. DA concentration in the dialysate was slightly but significantly increased in both groups during lever pressing. However, after consumption began, DA concentration increased in the sucrose group, but not in the sucrose plus ethanol group, then returned to baseline values. Ethanol consumption was low (0.27 ± 0.02 g/kg) and corresponded to low dialysate ethanol concentrations, which appeared within 5 minutes of drinking. The results show that operant self-administration of sucrose increases accumbal DA concentration during consummatory phases of behavior, but that a similar increase is not apparent when a novel, perhaps aversive, solution (sucrose plus ethanol) is presented. This difference may be due to the sensory-related stimulus properties of each solution. In addition, oral self-administration of ethanol at 0.27 ± 0.02 g/kg over 20 minutes is not sufficient for stimulation of DA activity in the NA. NIAAA Glossary Terms:  ethanol, AOD consumption, nucleus accumbens, dopamine, operant conditioning, sucrose, appetite, animal behavior, laboratory rat, microdialysis, sensory stimuli, animal study

Arturo González-Quintela, Maria-Jesus Dominguez-Santalla, Lourdes Loidi, Celsa Quinteiro, and Luis F. Perez.  Relation of tumor necrosis factor (TNF) gene polymorphisms with serum concentrations and in vitro production of TNF-alpha and interleukin-8 in heavy drinkers. Alcohol 34(2):273-277, October 2004.

Summary: Tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8) play a role in the pathogenesis of alcoholic hepatitis. This study investigated the possible relation of TNF gene polymorphisms with TNF-α and IL-8 synthesis in heavy drinkers (n = 19) and healthy control subjects (n = 14). Investigations included (1) polymorphisms in the TNF promoter region at positions -238 (G to A), -308 (G to A), -857 (C to T), and -863 (C to A), as well as a biallelic Ncol restriction fragment length polymorphism (RFLP) in the first intron of the close TNF-beta gene; (2) serum TNF-α and IL-8 concentrations; and (3) TNF-α and IL-8 production by phytohemagglutinin A-stimulated peripheral blood mononuclear cells. Compared to controls, heavy drinkers showed higher TNF-α production, higher IL-8 production, and higher serum IL-8 concentrations. Increased serum TNF-α concentrations were specifically found in heavy drinkers with the -857 (C to T) substitution (CT heterozygotes), indicating an interaction between alcohol consumption and that polymorphism on serum TNF-α concentrations. NIAAA Glossary Terms:  tumor necrosis factor-alpha, interleukin-8, cytokines, alcoholic hepatitis, pathogenesis, genetic polymorphism, gene, heavy AOD use, leukocytes, controlled study, comparative study, genetic correlation analysis, human study

Joydeep D. Chaudhuri.  Effect of a single dose of ethanol on developing skeletal muscle of chick embryos.  Alcohol 34(2):279-283, October 2004.

Summary: Many children with fetal alcohol syndrome (FAS) show retarded postnatal physical growth despite adequate nutrition. Based on findings from animal studies, it has been proposed that this is due to allometric retardation of growth of skeletal muscle, although the exact reasons for this are unknown. The present study examined the structural changes in skeletal muscle in FAS in an attempt to understand the mechanisms of growth retardation in FAS. Chick embryos were exposed to single doses of 5%, 10%, and 15% ethanol, and the effects on the general growth and development, as well as on the skeletal muscle, were studied. There was a significant retardation in crown-rump length, head circumference, and body weight in ethanol-exposed chicks when these parameters were compared with findings for control groups. These retardations were associated with significant and proportionate reductions in the weights of skeletal muscles. Microscopic examination of skeletal muscle showed areas of neutrophil infiltration and necrosis, suggestive of muscle damage, in chicks exposed to 10% and 15% ethanol. The findings demonstrate the direct toxic effects of a single dose of ethanol on developing embryos in general and skeletal muscle in particular. The pathologic changes seen in skeletal muscle could account for the failure in postnatal growth in FAS. NIAAA Glossary Terms:  ethanol, fetal alcohol syndrome, prenatal alcohol exposure, growth retardation, skeletal muscle, controlled study, microscopy, neutrophilic cell, necrosis, controlled study, animal study

Jean-Christophe Cassel, Hélène Jeltsch, Julie Koenig, and Byron C. Jones.  Locomotor and pyretic effects of MDMA–ethanol associations in rats.  Alcohol 34(2):285-289, October 2004.

Summary: Ecstasy (MDMA; 3,4-methylenedioxymethamphetamine) is a popular club drug often used in combination with ethanol. This study investigated the effects of MDMA and ethanol combinations on locomotor activity and body temperature of rats. Male Long-Evans rats were treated daily for 4 consecutive days with a 10-mg/kg dose of MDMA with or without a 1.5-g/kg dose of ethanol. MDMA increased spontaneous activity (on average +1,140%), and this increase was potentiated by ethanol on all days (on average +1,710%). Ethanol also inhibited MDMA-induced hyperthermia (on average −1.3°C) by the first day of treatment, but not on subsequent treatment days, supporting the suggestion that tolerance to this effect may develop. The findings suggest that combined ethanol-MDMA may induce effects on locomotor activity and thermoregulation that involve separate mechanisms, the first one being less sensitive to tolerance than the second one might be. Results of this study have important implications for understanding the motivation and the health risks of multiple drug abusers who combine ecstasy and ethanol. NIAAA Glossary Terms:  MDMA, amphetamines, ethanol, multiple drug use, locomotion, laboratory rat, drug interaction, hyperthermia, AOD tolerance, thermoregulation, motivation, health related behavior, risk-taking behavior, controlled study, animal study

T.R. Jerrells.  Introduction to the special issue on role of fatty liver, dietary fatty acid supplements, and obesity in the progression of alcoholic liver disease (Editorial).  Alcohol 34(1):1, August 2004.

(No abstract available.)

Vishnudutt Purohit, Denise Russo, and Paul M. Coates.  Role of fatty liver, dietary fatty acid supplements, and obesity in the progression of alcoholic liver disease: Introduction and summary of the symposium.  Alcohol 34(1):3-8, August 2004.

Summary: This article summarizes papers presented at the symposium on "Role of Fatty Liver, Dietary Fatty Acid Supplements, and Obesity in the Progression of Alcoholic Liver Disease," in Bethesda, Maryland, USA, October 2003. The symposium was sponsored by the National Institute on Alcohol Abuse and Alcoholism and the Office of Dietary Supplements. Alcoholic fatty liver is a pathologic condition that may predispose the liver to further injury (hepatitis and fibrosis) by cytochrome P450 2E1 induction, free radical generation, lipid peroxidation, nuclear factor-κ B activation, and increased transcription of proinflammatory mediators, including tumor necrosis factor-α. Increased acetaldehyde production and lipopolysaccharide-induced Kupffer cell activation may further exacerbate liver injury. Acetaldehyde may promote hepatic fat accumulation by impairing the ability of peroxisome proliferator-activated receptor α to bind deoxyribonucleic acid, and by increasing the synthesis of sterol regulatory binding protein-1. Unsaturated fatty acids  exacerbate alcoholic liver injury by increasing oxidative stress, whereas saturated fatty acids are protective. Polyenylphosphatidylcholine may prevent liver injury by down-regulating cytochrome P450 2E1 activity, attenuating oxidative stress, reducing the number of activated hepatic stellate cells, and up-regulating collagenase activity. Nonalcoholic steatohepatitis may develop through several mechanisms, such as oxidative stress, mitochondrial dysfunction, and associated impaired fat metabolism, dysregulated cytokine metabolism, insulin resistance, and altered methionine/S-adenosylmethionine/homocysteine metabolism. Obesity may contribute to the development of alcoholic liver disease by generating free radicals, increasing tumor necrosis factor-α production, inducing insulin resistance, and producing fibrogenic agents, such as angiotensin II, norepinephrine, neuropeptide Y, and leptin. Finally, alcoholic fatty liver transplant failure may be linked to oxidative stress. In vitro treatment of fatty livers with interleukin-6 may render allografts safer for clinical transplantation. NIAAA Glossary:  alcoholic fatty liver, hepatitis, fibrosis, cytochrome P450 2E1, inflammation, tumor necrosis factor-alpha, acetaldehyde, lipopolysaccharide, Kupffer cell, alcoholic liver disorder, peroxisome, DNA, unsaturated fatty acids, oxidative stress, saturated fatty acids, protective factors, hepatic stellate cell, collagen, mitochondria, fats, lipid metabolism disorder, cytokines, metabolic disorder, insulin, methionine, S-adenosylmethionine, homocysteine, obesity, free radicals, angiotensin, norepinephrine, neuropeptide Y, interleukin-6, organ transplantation

Charles S. Lieber.  Alcoholic fatty liver: Its pathogenesis and mechanism of progression to inflammation and fibrosis.  Alcohol 34(1):9-19, August 2004.

Summary: The pathogenesis of alcoholic steatosis and the mechanisms of its progression to liver inflammation and fibrosis are reviewed. Alcoholic liver disease is due both to malnutrition and to hepatotoxicity from ethanol-derived acetaldehyde (Ald) via the alcohol dehydrogenase (ADH) and cytochrome P450 2E1 (CYP2E1) pathways. ADH-mediated ethanol metabolism also generates reduced nicotinamide adenine dinucleotide (NADH), which promotes steatosis by stimulating the synthesis of fatty acids (FAs) and inhibiting their oxidation. Steatosis is also promoted by excess dietary lipids and can be attenuated by their replacement with medium-chain triglycerides. Through reduction of pyruvate, elevated NADH also increases lactate, which stimulates collagen synthesis in myofibroblasts. Furthermore, CYP2E1 activity is inducible by its substrates, which include FAs as well as ethanol. Their excess and metabolism by  this pathway generates free radicals, which cause oxidative stress, with peroxidation of lipids, membrane damage, and altered enzyme activities. Products of lipid peroxidation such as 4-hydroxynonenal stimulate collagen generation and fibrosis, which are further increased through diminished feedback inhibition of collagen synthesis because Ald forms adducts with the carboxyl-terminal propeptide of procollagen in hepatic stellate cells. Ald is also toxic to mitochondria, and it aggravates their oxidative stress by binding to reduced glutathione and promoting its leakage. Oxidative stress and associated cellular injury promote inflammation, which is aggravated by increased production of tumor necrosis factor (TNF)-α in Kupffer cells. These are activated by induction of their CYP2E1 as well as by endotoxin. The endotoxin-stimulated TNF-α release is decreased by dilinoleoylphosphatidylcholine, the active phosphatidylcholine (PC) species of polyenylphosphatidylcholine (PPC). Moreover, defense mechanisms provided by peroxisome proliferator-activated receptor α and Ω FA oxidation are readily overwhelmed, particularly in female rats as well as in women who have low hepatic induction of FA-binding protein (L-FABPc). The intracellular concentration of free FAs may then become high enough to damage membranes, thereby contributing to necrosis, inflammation, and progression to fibrosis and cirrhosis. Eventually, hepatic S-adenosylmethionine and PCs become depleted in alcoholism, with impairment of their multiple cellular functions, which can be restored by PC replenishment. Thus prevention and therapy opposing the development of steatosis and its progression to more severe injury can be achieved by multiple approaches including control of alcohol consumption, avoidance of obesity and excess dietary long-chain FAs or replacing them with medium-chain FAs, and replenishment of S-adenosylmethionine and PCs by using PPC. Progress in the understanding the pathogenesis of alcoholic fatty liver and its progression to inflammation and fibrosis has resulted in prospects for improved prevention and treatment. NIAAA Glossary:  AOD dependence, alcoholic fatty liver, inflammation, fibrosis, alcoholic liver cirrhosis, hepatotoxicity, acetaldehyde, lipids, diet, malnutrition, triglycerides, alcohol dehydrogenases, cytochrome P450 2E1, NADH oxidoreductases, fatty acids, collagen, phosphatidylcholine, adduct, Kupffer cells, AOD consumption, obesity, S-adenosylmethionine, oxidative stress, free radicals, peroxidation, necrosis, cell membrane, pathogenesis, tumor necrosis factor-alpha, ethanol metabolism, binding proteins, hepatic stellate cell, endotoxins, prevention approach, treatment method, literature review

Amin A. Nanji.  Role of different dietary fatty acids in the pathogenesis of experimental alcoholic liver disease (Literature review).  Alcohol 34(1):21-25, August 2004.

Summary: Dietary fatty acids and alcohol play an important role in the pathogenesis of alcoholic liver disease. Studies in rats show that dietary fat has a steatogenic role. A role for polyunsaturated fatty acids in alcoholic liver disease is supported by studies showing that pathologic changes occur only in rats fed ethanol with polyunsaturated fatty acids. The mechanisms by which the fatty acids promote alcoholic liver disease include enhanced oxidative stress, production of endotoxin, and increased expression of proinflammatory cytokines. NIAAA Glossary:  fatty acids, diet, ethanol, alcoholic liver disorder, pathogenesis, fatty liver, animal study, laboratory rat, unsaturated fatty acids, oxidative stress, endotoxins, inflammation, cytokines, literature review

Robert J. Pawlosky and Norman Salem Jr.  Perspectives on alcohol consumption: liver polyunsaturated fatty acids and essential fatty acid metabolism (Review).  Alcohol 34(1):27-33, August 2004.

Summary: Concentrations of several polyunsaturated fatty acids (PUFAs) are reduced in alcoholic liver disease, including 18:2n6, 18:3n6, 20:3n6, 18:3n3, 22:5n3, and 22:6n3, but not 20:4n6 and 22:4n6, nor 22:5n6, compared with patients with primary biliary cirrhosis and control subjects. Animal studies also have shown reduced liver PUFA content after prolonged alcohol consumption. The effect of ethanol on the elongation and desaturation of essential fatty acids is complex, however, as in vitro study results indicate that the direction of alcohol's effect may be related to its dose. Studies of cultured hepatocytes showed that ethanol increased Δ5 and Δ6 desaturase activities throughout a broad concentration range. In contrast, lower liver desaturase activity has been reported in animals consuming high concentrations of alcohol (36%–40% of energy intake) over several months. In vivo isotope tracer studies in animals indicate that prolonged periods of moderate alcohol consumption (mean consumption 2.6 g/kg/day for primates and 1.2 g/kg/day for felines) had no effect on the uptake of either linoleic (18:2n6) or α-linolenic (18:3n3) acids into the plasma and led to an increased incorporation of these deuterated precursors into 20:4n6 and 22:6n3. This probably reflects stimulated, rather than inhibited, production of long-chain PUFAs. Numerous studies in various species have shown that alcohol consumption can increase lipid peroxidation in tissues, and sustained periods of ethanol-induced peroxidation can deplete tissue PUFAs. The authors of this article present a hypothesis to rationalize the long-term effects of alcohol consumption on liver PUFA concentration that takes into consideration ethanol's effect on the metabolism of essential fatty acids. NIAAA Glossary: ethanol, alcoholic liver disorder, unsaturated fatty acids, AOD consumption, moderate AOD use, animal studies, linoleic acid, linolenic acid, enzymes, lipids, peroxidation, hypothesis testing, metabolism, animal study, in vivo study, hepatocyte, cell culture study, deuterium, literature review

David W. Crabb, Andrea Galli, Monika Fischer, and Min You.  Molecular mechanisms of alcoholic fatty liver: role of peroxisome proliferator-activated receptor alpha.  Alcohol 34(1):35-38, August 2004.

Summary: The regulation of hepatic fatty acid (FA) metabolism depends crucially on normal function of peroxisome proliferator-activated receptor-alpha (PPARα). FAs serve as ligands for PPARα, and when their levels increase, PPARα activation induces a battery of FA-metabolizing enzymes to restore FAs to normal levels. Although ethanol consumption increases hepatic FA levels, in vitro study has shown that ethanol metabolism inhibits the ability of PPARα to bind DNA and activate reporter genes. Ethanol feeding of C57BL/6J mice for 4 weeks also impairs FA catabolism in liver by blocking PPARα-mediated responses. Ethanol feeding reduced the level of retinoid X receptor-alpha (RXRα) as well as the ability of PPARα/RXR in liver nuclear extracts to bind its consensus sequence, and the levels of mRNAs for several PPARα-regulated genes were reduced [long-chain acyl coenzyme A (acyl-CoA) dehydrogenase and medium-chain acyl-CoA dehydrogenase] or failed to be induced (acyl-CoA dehydrogenase, liver carnitine palmitoyl-CoA transferase I, very long-chain acyl-CoA synthetase, very long-chain acyl-CoA dehydrogenase) in livers of the ethanol-fed animals. Consistent with this finding, ethanol feeding did not induce the rate of FA beta (β)-oxidation, as assayed in liver homogenates. Inclusion of the PPARα agonist WY14,643 in the diet restored the DNA-binding activity of PPARα/RXR, induced mRNA levels of several PPARα target genes, stimulated the rate of FA β-oxidation in liver homogenates, and prevented fatty liver in ethanol-fed animals. Blockade of PPARα function during ethanol consumption contributes to the development of alcoholic fatty liver, which can be overcome by WY14,643. NIAAA Glossary:  peroxisome, ethanol metabolism, AOD consumption, liver, fatty acids, metabolism, ligand, DNA, mRNA, in vitro study, gene expression, animal study, laboratory mice, retinoids, enzymes, coenzyme A, oxidoreductases, transferases, agonists, diet, oxidation, literature review

Min You and David W. Crabb.  Molecular mechanisms of alcoholic fatty liver: Role of sterol regulatory element-binding proteins (Review).  Alcohol 34(1):39-43, August 2004.

Summary: Alcoholic fatty liver is the earliest and most common response of the liver to heavy alcohol use and may be a precursor of more severe forms of liver injury. The authors and their colleagues found that in two rat hepatoma cell lines ethanol markedly induced transcription of a sterol regulatory element-binding protein (SREBP)-regulated promoter through increased levels of mature SREBP-1 protein. Ethanol's effect in the hepatoma cells was blocked by inhibition of ethanol oxidation with 4-methylpyrazole, while ethanol's effect was enhanced by the aldehyde dehydrogenase inhibitor cyanamide, indicating that the effect is probably mediated by acetaldehyde. Consistent with these in vitro findings, consumption of a low-fat diet with ethanol by mice for 4 weeks caused a significant increase of the active form of hepatic SREBP-1. Activation of SREBP-1 by ethanol feeding was associated with increased expression of lipogenic genes as well as triglyceride accumulation in the livers. Overall, these findings suggest that ethanol metabolism increased hepatic lipogenesis by activating SREBP-1 and that this effect of ethanol may contribute to the development of alcoholic steatosis. The authors and their colleagues further studied the mechanisms of ethanol activation of SREBP-1 by identifying a new target of ethanol, adenosine 5′-monophosphate-activated protein kinase (AMP-APK). The results demonstrated that ethanol's effect on SREBP-regulated promoter activation was mediated, at least partly, through inhibition of AMP-APK. Consistent with this hypothesis, chronic ethanol feeding (4 weeks) resulted in significantly reduced activity and protein level of AMP-APK and increased acetyl coenzyme A carboxylase activity in the mouse livers. NIAAA Glossary:  alcoholic fatty liver, pathogenesis, cell culture study, ethanol metabolism, enzyme inhibitors, acetaldehyde, alcohol dehydrogenases, aldehyde dehydrogenases, 4-methylpyrazole, cyanamide, in vitro study, binding proteins, gene expression, lipids, triglycerides, protein kinases, biochemical mechanism of action, chronic AODE, coenzyme A, animal study, laboratory mice

M. Raj Lakshman.  Some novel insights into the pathogenesis of alcoholic steatosis (Review).  Alcohol 34(1):45-48, August 2004.

Summary: This review summarizes new knowledge about the pathogenesis of alcoholic fatty liver, a complex process involving some or all of the following: increased fat synthesis, increased mobilization of depot fat, defective export of fat from the liver, and decreased fat breakdown. Some of the novel findings in these mechanisms involve the down-regulation of peroxisome proliferator-activated receptor alpha (α) and up-regulation of lipogenic enzymes through the induction of sterol regulatory element-binding protein. Another mechanism is the adenosine 5′-monophosphate-activated protein kinase, which, through a complex mechanism, may regulate the relative concentrations of intracellular malonyl coenzyme A and long-chain acyl-coenzyme A, the key metabolites responsible for the balance between fat synthesis and fat degradation pathways. Finally, excess dietary intake of omega 6 (Ω6) polyunsaturated fatty acids (PUFAs) may exacerbate alcohol-induced onset of hepatic steatosis and alcoholic liver disease, which may explain why supplementation with lecithin containing Ω6 PUFAs in a recent clinical trial in humans failed to show any benefits, although it was partially effective in an animal model. In contrast, dietary intake of Ω3 PUFAs in moderation may have a protective effect against steatosis and alcoholic liver disease. NIAAA Glossary:  pathogenesis, alcoholic fatty liver, metabolism, biosynthesis, fats, biochemical mechanism of action, peroxisomes, enzymes, binding proteins, sterols, protein kinases, coenzyme A, unsaturated fatty acids, alcoholic liver disorder, clinical trial, human study, protective factors

Zhi Zhong and John J. Lemasters.  Role of free radicals in failure of fatty liver grafts caused by ethanol.  Alcohol 34(1):49-58, August 2004.

Summary: Fat is an important risk factor for initial poor function and failure of human liver grafts; a major factor may be increased oxidative stress. This study examined the role of free radical stress and the efficacy of antioxidant treatments in fatty liver graft injury. Donors for orthotopic rat liver transplantation were treated with ethanol chronically (3 or more weeks) and acutely (single dose). After transplantation, necrosis and alanine aminotransferase release were three to four times higher in recipients of fatty grafts from ethanol-treated (chronically or acutely) donors compared with findings for recipients of grafts from untreated donors, and graft survival decreased from nearly 100% to less than 20%. Free radical adducts were detected in the blood and bile of rats receiving fatty grafts caused by ethanol. Markers of lipid peroxidation also increased after transplantation. Destruction of Kupffer cells with gadolinium chloride decreased free radical production and improved graft survival. Leukocyte adhesion increased beginning early after implantation, and adherent white blood cells (WBCs) obtained from transplanted fatty livers produced the same free radical species that were detected in blood. Thus Kupffer cells and adherent WBCs are important sources of free radicals. Free radicals not only damage fatty grafts directly but also lead to enhanced inflammation and disturbed microcirculation. Delivery of superoxide dismutases -1 and -2 genes, free radical-scavenging polyphenols, and antioxidant-containing Carolina Rinse solution reduced injury and improved survival of fatty grafts caused by ethanol. These findings indicate that free radicals increase in fatty grafts after transplantation and play an important role in injury of fatty grafts obtained from ethanol-exposed donors. Treatment of fatty donor livers with antioxidants and free radical scavengers may be clinically effective in preventing failure of fatty grafts. NIAAA Glossary:  alcoholic fatty liver, organ transplantation, treatment outcome, free radicals, Kupffer cell, leukocytes, adduct, inflammation, superoxide dismutases, gene, polyphenols, microcirculation, antioxidants, laboratory rat, animal study

Bin Gao.  Therapeutic potential of interleukin-6 in preventing obesity- and alcohol-associated fatty liver transplant failure (Review).  Alcohol 34(1):59-65, August 2004.

Summary: The only effective treatment for chronic end-stage liver disease and acute liver failure is orthotopic liver transplantation, an intervention that is hindered by a shortage of donor organs. A further complication is the prevalence of steatosis in 13% to 50% of donor livers obtained from obese and alcoholic individuals. These livers, when transplanted, are associated with primary nonfunction and increased risk of dysfunction. Findings by the author's group show that in vitro treatment with interleukin-6 (IL-6) dramatically reduces mortality, liver injury, and necrapoptosis in steatotic Zucker rat liver isografts. Additional studies indicate that IL-6 induces hepatoprotection of steatotic liver isografts by preventing sinusoidal endothelial cell damage, thus ameliorating hepatic microcirculation, and by protecting against hepatocyte death, which is probably mediated through activation of signal transducer and activator of transcription 3/Bcl-xL. In vitro IL-6 treatment also prevents mortality associated with alcoholic fatty liver transplants. Relative to the protective effect of IL-6 on steatotic Zucker rat liver, IL-6 is less effective in alcoholic fatty livers, which may be due to inhibitory effects of ethanol on IL-6 activation of signal transducer and activator of transcription 3 in hepatocytes and sinusoidal endothelial cells. These findings support the view that in vitro IL-6 treatment of steatotic livers may render allografts usable for clinical transplantation, thereby ameliorating the short supply of cadaver liver allografts. Higher concentrations of IL-6 may be required to protect against alcoholic fatty liver isograft injury because alcohol inhibits IL-6 signaling in the liver. NIAAA Glossary:  alcoholic fatty liver, fatty liver, AOD dependence, obesity, organ transplantation, treatment complications, liver damage, mortality, animal study, laboratory rat, interleukin-6, microcirculation, hepatocyte, endothelial cell, in vitro study, signal transduction, ethanol, treatment approach

Craig J. McClain, Sri Prakash L. Mokshagundam, Shirish S. Barve, Zhenyuan Song, Daniell B. Hill, Theresa Chen, and Ion Deaciuc.  Mechanisms of non-alcoholic steatohepatitis (Review).  Alcohol 34(1):67-79, August 2004.

Summary: The authors review the definition and clinical features of nonalcoholic steatohepatitis (NASH), potential mechanisms of NASH, and potential therapeutic interventions in NASH. The term nonalcoholic steatohepatitis was coined in 1980 to describe a new syndrome occurring in patients who usually were obese and often diabetic females who denied alcohol use but had a liver biopsy picture consistent with alcoholic hepatitis. There was no defined therapy for this syndrome and its causes were unknown. Even now this clinical syndrome is only somewhat better understood, and still there is no Food and Drug Administration-approved or even generally accepted drug therapy. Patients with primary NASH typically have the insulin resistance syndrome, which is characterized by obesity, diabetes, hyperlipidemia, hypertension, and, in some instances, other metabolic abnormalities such as polycystic ovary disease. Secondary NASH may be caused by drugs such as tamoxifen, certain industrial toxins, rapid weight loss, and other factors. The cause of NASH remains elusive, but most investigators agree that a baseline of steatosis requires a second hit capable of inducing inflammation, fibrosis, or necrosis for NASH to develop. The authors' research group has focused on the interactions of nutritional abnormalities, cytokines, oxidative stress with lipid peroxidation, and mitochondrial dysfunction in the induction of both alcoholic and nonalcoholic steatohepatitis. Research findings from other laboratories also support the role of increased cytokine activity, oxidative stress, and mitochondrial dysfunction in the pathogenesis of NASH. NIAAA Glossary:  metabolic disorder, insulin, liver disorder, fatty liver, hepatitis, diagnostic problem, biopsy, obesity, diabetes, hyperlipidemia, hypertensive disorder, ovary, drug therapy, toxic substances, inflammation, fibrosis, necrosis, nutritional deficiency, cytokines, oxidative stress, peroxidation, lipids, mitochondria, pathogenesis, liberature review

Anna Mae Diehl.  Obesity and alcoholic liver disease (literature review).  Alcohol 34(1):81-87, August 2004.

Summary: Alcohol-induced liver damage is potentiated by obesity. This article reviews the mechanisms by which adiposity and ethanol interact to produce fatty liver and steatohepatitis. Exacerbation of the proinflammatory state that induces tumor necrosis factor (TNF) activity and hepatic insulin resistance seems to be involved, but controversity remains over the precise cellular signals that culminate in hepatocyte dysfunction and death. Hepatocyte apoptosis and necrosis are both likely, but more study is needed to develop optimal hepatoprotective strategies. Whether the hepatotoxic consequences of obesity and ethanol ingestion are additive or synergistic is unclear, although such information has important prognostic implications and might be useful in forumulating guidelines for safe alcohol consumption based on body mass index. Animal studies raise questions about the relation between steatohepatitis and cirrhosis. Despite overwhelming evidence that obesity promotes alcohol-induced steatosis and steatohepatitis, most obese humans (and mice) who drink alcohol do not develop cirrhosis. Even severe steatohepatitis in mice seldom leads to cirrhosis, making it conceivable tha, steatohepatitis is a permissive factor for cirrhosis, but is neither necessary nor sufficient for cirrhosis to occur. Efforts to identify the proximal mediators of hepatic fibrosis probably should include investigating how various adipokines, neurotransmitters, and cytokines interact to regulate hepatic stellate cells. Such knowledge would allow investigators to explore further modifying actions of ethanol on these mechanisms. NIAAA Glossary:  alcoholic liver disorder, alcoholic liver cirrhosis, fatty liver, alcoholic hepatitis, human study, animal study, laboratory mice, pathogenesis, tumor necrosis factor, insulin, cytokines, hepatocyte, apopotosis, hepatotoxicity, inflammation, fibrosis, obesity, body mass index, recommendations or guidelines, adipose tissue, neurotransmitters

Jerrells TR.  A brief history of alcohol, immunity, and the Alcohol and Immunology Research Interest Group (AIRIG) (Editorial).  Alcohol 33(3):169-170, July 2004.

(No abstract available.)

Kovacs EJ and Jerrells TR.  Alcohol and immunology: Introduction to and summary of the 2003 Alcohol and Immunology Research Interest Group (AIRIG) meeting.  Alcohol 33(3):171-174, July 2004.

Summary: This article summarizes presentations of the 8th Meeting of the Alcohol and Immunology Research Interest Group (AIRIG). The meeting was held at Loyola University Medical Center, Maywood, Illinois, on November 21, 2003.  Nine speakers described their recent work on the combined effects of ethanol and injury, infection, or inflammatory challenge. Topics were (1) T-cell activation after chronic ethanol ingestion in mice, (2) effect of ethanol consumption on the severity of acute viral-mediated pancreatitis, (3) ethanol and alveolar macrophage dysfunction, (4) impaired intestinal immunity and barrier function: a cause for enhanced bacterial translocation in alcohol intoxication and burn injury, (5) immune consequences of the combined insult of acute ethanol exposure and burn injury, (6) consequences of alcohol-induced dysregulation of immediate hemodynamic and inflammatory responses to trauma/hemorrhage, (7) regulation of tumor necrosis factor-alpha production by Kupffer cells after chronic exposure to ethanol, (8) acute exposure to ethanol and suppression of cytokine responses induced through Toll-like receptors, and (9) inhibition of antigen-presenting cell functions by alcohol: implications for hepatitis C virus infection. The work described at the 8th Meeting of AIRIG is presented in the nine articles of this Special Issue of Alcohol. NIAAA Glossary Terms:  conference proceedings, T lymphocyte, ethanol, AOD intoxication, chronic AODE, acute AODE, pancreatitis, viral disease, disease severity, macrophage, lung disorder, inflammation, trauma, hemorrhage, cytokines, tumor necrosis factor-alpha, Kupffer cell, receptors, antigens, hepatitis C virus, infection

Cook RT, Zhu X, Coleman RA, Ballas ZK, Waldschmidt TJ, Ray NB, LaBrecque DR, and Cook BL.  T-cell activation after chronic ethanol ingestion in mice.  Alcohol 33(3):175-181, July 2004.

Summary: Chronic excessive ethanol consumption causes immunodeficiency in humans and in mice. Immunologic changes have been described in both species, including T-cell and innate immune system cell activation, among others. The features of chronic ethanol-induced activation have similarities in the two species, including an increased effector subset in both CD4+ and CD8+ T cells. There are also features of activation observed in the splenic macrophages of mice consuming ethanol chronically, including increased up-regulation of CD80 and CD86. Because these molecules are involved in T-cell–antigen-presenting cell interactions in vivo, it is of interest to ask whether these and other pathways of interaction are important in the T-cell activation and cytokine skewing described in chronic ethanol abuse. Preliminary findings from comparisons of wild-type, CD40 ligand knock-out, and CD28 knock-out C57BL/6 mice strongly support the suggestion of a critical role for T-cell–antigen-presenting cell interactions in the immune alterations observed in chronic ethanol abuse. NIAAA Glossary Terms:  ethanol, heavy AOD use, chronic AODE, immune system, immune response, cell-mediated immunity, T lymphocyte, macrophage, laboratory mice, animal study, receptors, cell membrane, antigens, cytokines, ligands, gene knockout technology, comparative study, conference proceedings

Clemens DL and Jerrells TR.  Ethanol consumption potentiates viral pancreatitis and may inhibit pancreas regeneration: Preliminary findings.  Alcohol 33(3):183-189, July 2004.

Summary: The pathogenesis of alcoholic pancreatitis remains poorly understood, partly because a suitable animal model to study this disease is lacking. It has been proposed that ethanol predisposes or sensitizes the pancreas to the effects of co-factors, and the combination of ethanol's effects on the pancreas and the actions of these co-factors results in alcoholic pancreatitis. A number of viruses are known to infect the pancreas, and the authors of this paper have suggested that a viral infection is one co-factor that could be involved in the development of alcoholic pancreatitis. One of the most-studied groups of viruses that infect the pancreas and cause pancreatitis in humans is the coxsackieviruses. The authors have shown that short-term (5–14 days) and subchronic (>28 days) administration of ethanol to mice increases the severity of coxsackie B3-induced pancreas damage. They hypothesize that ethanol consumption impairs pancreas regeneration after injury, similar to the effect of ethanol on liver regeneration. Preliminary data to support the hypothesis has been obtained by the authors using a murine model of coxsackie B3-mediated alcoholic pancreatitis. Specifically, consumption of ethanol by mice is associated with changes in the replication of acinar cells and their organization into acini after viral-mediated injury. The authors believe that this model will be valuable for studying the biochemical and molecular mechanisms involved in alcoholic pancreatitis. NIAAA Glossary Terms:  alcoholic pancreatitis, pathogenesis, animal model, laboratory mice, viral disease, infection, pancreas, disease factor, regeneration of body part, hypothesis testing, acinar cell, biochemical mechanism, molecular interaction, animal study, conference proceedings

Brown LAS, Harris FL, Ping XD, and Gauthier TW.  Chronic ethanol ingestion and the risk of acute lung injury: A role for glutathione availability?  Alcohol 33(3):191-197, July 2004.

Summary: A history of alcohol abuse is an independent variable in the development of acute respiratory distress syndrome. In the absence of cirrhosis, alcohol abuse decreased glutathione, the key antioxidant lining the alveolar space, by 80% and was associated with alveolar barrier leak. Neither the glutathione pool nor barrier leak was corrected by abstinence for 1 week. The authors suggest that this aberrant glutathione homeostasis may contribute to enhanced alveolar permeability, thereby increasing susceptibility to the development of acute respiratory distress syndrome. In a rat model, chronic ingestion of ethanol decreased pulmonary glutathione concentration, increased alveolar barrier permeability, and increased the risk of acute lung injury. In alveolar type II cells, chronic ingestion of ethanol altered cellular functions such as decreased surfactant processing, decreased barrier integrity, and increased sensitivity to cytotoxin-induced apoptosis in vitro and in vivo. In alveolar macrophages, chronic ingestion of ethanol decreased phagocytosis of microorganisms and decreased cell viability, events that would increase the risk of pneumonia. A central role for glutathione availability was demonstrated by the normalization of cellular function and viability of type II cells and macrophages as well as decreased sensitivity to endotoxemia-induced acute lung injury when glutathione precursors were added to the ethanol diet. These results support the suggestion that chronic ingestion of ethanol increased the risk of acute lung injury through the chronic oxidative stress resulting from ethanol-induced glutathione depletion. Because chronic oxidative stress alters cellular functions and viability, the lung becomes more susceptible when a second hit such as sepsis occurs. NIAAA Glossary Terms:   ethanol, chronic AODE, acute AODE, glutathione, antioxidants, oxidative stress,  pneumonia, respiratory disorder, lung disorder, macrophage, phagocytosis, cell function, apoptosis, infection, animal study, laboratory rat, conference proceedings

Choudhry MA, Rana SN, Kavanaugh MJ, Kovacs EJ, Gamelli RL, and Sayeed MM.  Impaired intestinal immunity and barrier function: A cause for enhanced bacterial translocation in alcohol intoxication and burn injury.  Alcohol 33(3):199-208, July 2004.

Summary: Multiple studies support the suggestion that patients who received burn injuries while under the influence of alcohol have higher infection rates and are more likely to die, compared with patients who sustained burn injuries in the absence of alcohol intoxication. Thus infection becomes the primary cause of death in burn-injured patients. Studies in experimental animals have examined whether alcohol intoxication before burn injury enhances bacterial translocation from the intestine, a major source of bacteria. These studies have shown a several-fold increase in bacterial translocation from the intestine in the group of animals receiving combined insult of alcohol intoxication and burn injury compared with findings for the groups receiving either insult alone. Alcohol intoxication and burn injury independent of each other have also been shown to cause an increase in bacterial translocation. The gastrointestinal tract normally maintains a physical mucosal and immunologic barrier that provides an effective defense in keeping bacteria within the intestinal lumen. However, in injury conditions these defense mechanisms are impaired. Intestinal bacteria consequently gain access to extraintestinal sites. Intestine-derived bacteria are implicated in causing systemic infection and in subsequent multiple organ dysfunction in both immunocompromised patients and patients with injury, such as burn and trauma. The authors of this paper discuss three potential mechanisms that are likely to contribute to the increase in bacterial translocation in alcohol intoxication and burn injury: (1) increase in bacterial growth in the intestine, (2) physical disruption of mucosal barrier of the intestine, and (3) suppression of the immune defense in the intestine. NIAAA Glossary Terms:  ethanol, AOD intoxication, injury, fire, intestinal mucosa, bacteria,  infection,  gastrointestinal tract, gastrointestinal disorder, immune disorder, immune response, animal study, conference proceedings

Kovacs EJ, Faunce DE, and Messingham KAN.  Ethanol and burn injury: Estrogen modulation of immunity.  Alcohol 33(3):209-216, July 2004.

Summary: There is abundant clinical evidence that alcohol is a causative factor in the occurrence of burn or other traumatic injury. More recent evidence shows that individuals who are injured while under the influence of alcohol have increased morbidity and mortality compared with those with comparable injuries who did not consume alcohol. Many of the complications seen in ethanol-exposed, burn-injured subjects result from depressed immune responses that render the host unable to fight off infectious organisms. Both injury and ethanol exposure independently affect cellular immune responses, including delayed-type hypersensitivity and splenocyte proliferative responses, and the combined insult of ethanol exposure and injury acts in conjunction to increase further the magnitude and duration of immunosuppression. Interestingly, these immune responses can be restored experimentally in male, but not in female, mice by administration of low, proestrous levels of estrogen. The complexity of the responses after injury in ethanol-exposed subjects is multiplied when the sex of the subjects is added to the equation. This is partly due to the effect of the combined insult of injury and ethanol on the production of gonadal steroid hormones in males and females and the direct effects of those hormones on cytokine gene expression in sensitive cell types such as the macrophage. Evidence seems to indicate that cellular immune responses after ethanol exposure and burn injury differ in kinetics and magnitude for male and female subjects.  Therefore therapeutic interventions to treat burn-injured patients should take into account both sex and ethanol exposure. NIAAA Glossary Terms:  injury, trauma, fire, AODR mortality, morbidity, immune response, infection, cell-mediated immunity, gender differences, estrogens, macrophage, sex hormones, steroid hormones, cytokines, gene expression, treatment factors, conference proceedings

Molina PE, Zambell KL, Norenberg K, Eason J, Phelan H, Zhang P, Stouwe CV, Carnal JW, and Porreta C.  Consequences of alcohol-induced early dysregulation of responses to trauma/hemorrhage.  Alcohol 33(3):217-227, July 2004.

Summary: Studies from the authors' laboratory have examined the early hemodynamic, proinflammatory, and neuroendocrine alterations in responses to hemorrhagic shock in surgically catheterized, conscious, unrestrained, male Sprague-Dawley rats during acute alcohol intoxication (1.75-g/kg bolus, followed by a constant 15-hour infusion at a rate of 250–300 mg/kg/hour). With both fixed-pressure (40 mm Hg) and fixed-volume (50%) hemorrhagic shock, followed by fluid resuscitation with Ringer's lactate, acute (15-hour) alcohol intoxication significantly impaired the immediate hemodynamic, metabolic, and inflammatory counterregulatory responses to hemorrhagic shock. Alcohol intoxication enhanced hemodynamic instability during blood loss and impaired the recovery of mean arterial blood pressure during fluid resuscitation. Activation of neuroendocrine pathways involved in restoring hemodynamic stability was significantly weakened in intoxicated hemorrhaged animals. The hemodynamic and neuroendocrine impairment is associated with enhanced expression of lung and spleen tumor necrosis factor, and it suppressed circulating neutrophil function. In addition, neuroimmune regulation of cytokine production by spleen-derived macrophages obtained from alcohol-intoxicated hemorrhaged animals was impaired when examined in vitro. The authors hypothesize that impaired neuroendocrine activation contributes to hemodynamic instability, which, in turn, prolongs tissue hypoperfusion and enhances risk for tissue injury. Specifically, they hypothesize that the early dysregulation in counterregulatory responses affects host defense mechanisms during the recovery period. They examined host response to systemic (cecal ligation and puncture) and localized (pneumonia) infectious challenge in animals recovering from hemorrhage during acute alcohol intoxication and observed increased morbidity and mortality from infection in alcohol-intoxicated hemorrhaged animals. Their results indicate that alcohol-induced alterations in early hemodynamic and neuroimmune responses to shock increase susceptibility to infection during the early recovery period. NIAAA Glossary Terms:  hemorrhage, ethanol, AOD intoxication, acute AODE, blood circulation, blood pressure, neurohormones, neuroendocrinology (field), tumor necrosis factor, neutrophilic cell, inflammation, immune system, immune response, pneumonia, infection, morbidity, mortality, AODR mortality, neuroimmune system, hypothesis testing, animal study, laboratory rat,conference proceedings

Nagy LE.  Stabilization of tumor necrosis factor-alpha mRNA in macrophages in response to chronic ethanol exposure.  Alcohol 33(3):229-233, July 2004.

Summary: Tumor necrosis factor-alpha (TNF-α) is one of a number of cytokines implicated in the progression of alcohol-induced liver disease. Activation of hepatic macrophages by lipopolysaccharide (LPS) during exposure to ethanol is thought to be an important mechanism for stimulation of TNF-α expression. Chronic exposure of macrophages to ethanol, both in vivo after ad libitum feeding of ethanol for 4 weeks and in culture for 48 hours, has an impact on specific elements within the LPS-stimulated signaling cascade, disrupting both transcriptional and posttranscriptional regulation of TNF-α biosynthesis. Stabilization of TNF-α messenger ribonucleic acid (mRNA) after chronic exposure to ethanol is one important mechanism for increased TNF-α production by hepatic macrophages. Increased LPS stimulation of p38 mitogen-activated protein kinase contributes to this stabilization of TNF-α mRNA in macrophages. Stabilization of TNF-α mRNA after chronic exposure to ethanol requires both cis-acting elements in the TNF-α mRNA and trans-acting mRNA-binding proteins. The adenosine plus uridine–rich element in the 3′ untranslated region of the TNF-α mRNA is an important regulator of TNF-α mRNA stability. Its activity is required for stabilization of TNF-α mRNA induced by chronic exposure to ethanol. Moreover, results from studies have demonstrated that at least one mRNA-binding protein, HuR, is also involved in stabilization of TNF-α mRNA stability after chronic exposure to ethanol. Taken together, the results from these studies identify the regulation of TNF-α mRNA stability as a novel mechanism by which chronic exposure to ethanol increases the expression of TNF-α. NIAAA Glossary Terms:  tumor necrosis factor-alpha, cytokines, alcoholic liver disorder, disease course, macrophage, lipopolysaccharide, ethanol, biosynthesis, mitogens, protein kinases, gene transcription, mRNA, RNA translation, gene expression, biochemical mechanism, cell culture study, conference proceedings

Pruett SB, Zheng Q, Fan R, Matthews K, and Schwab C.  Acute exposure to ethanol affects Toll-like receptor signaling and subsequent responses: An overview of recent studies.  Alcohol 33(3):235-239, July 2004.

Summary: Innate resistance to a variety of microbes is suppressed by ethanol. Studies from both the authors' laboratory and other laboratories indicate suppression of responses is mediated through two Toll-like receptors (TLRs): TLR3 and TLR4. TLR-mediated responses are important in innate immunity. In this article the authors review recent findings from their laboratory studies indicating that ethanol also suppresses responses mediated through other TLRs. This supports the possibility that suppression of these responses may constitute a major mechanism by which ethanol suppresses innate immunity. The authors also examined ethanol-induced changes in cellular signaling and in patterns of gene expression induced through TLR3 in mouse peritoneal macrophages; the results are reviewed in this article. Signaling through TLR3 was inhibited, and results of DNA microarray analysis supported the notion that inhibition of an interferon-related amplification loop might be responsible for suppression of gene expression for several effector molecules of innate immunity and inflammation not previously known to be altered by ethanol. Thus ethanol alters responses through most or all mouse TLRs, and this suppresses expression of a wide range of innate immune mediators. NIAAA Glossary Terms:  ethanol, immune response, receptors, cell signaling, immunosuppressive effect, gene expression, DNA, interferon, animal study, laboratory mice, conference proceedings

Szabo G, Dolganiuc A, Mandrekar P, and White B.  Inhibition of antigen-presenting cell functions by alcohol: Implications for hepatitis C virus infection.  Alcohol 33(3):241-249, July 2004.

Summary: The mechanisms of alcohol-induced immunosuppression include defects in innate and adaptive immune responses. Monocytes and dendritic cells (DCs) link innate and adaptive immune responses as they recognize viral antigens and induce antigen-specific T-cell activation. The authors investigated the effects of alcohol on antigen-presenting cell functions. Acute alcohol consumption by healthy volunteers (vodka, 2 ml/kg) resulted in significantly reduced antigen-presenting cell function of monocyte-derived DCs. Reduced allostimulatory capacity of DCs treated with alcohol in vitro correlated with decreased co-stimulatory molecule (B7.1 and B7.2) expression, as well as with reduced interleukin (IL)-12 and increased IL-10 concentrations, in mixed lymphocyte cultures. Dendritic cells recognize viral antigens in hepatitis C virus (HCV) infection, and HCV disease is accelerated in alcohol-dependent individuals. For patients with chronic HCV infection, we found reduced allostimulatory capacity of myeloid DCs. Furthermore, DC function was reduced by in vitro alcohol treatment of DCs obtained from HCV-infected patients, supporting the suggestion that viral factors and alcohol may interact to doubly suppress DC functions. Induction of maturation with lipopolysaccharide could not fully ameliorate the reduced DC allostimulatory capacity caused by alcohol treatment, HCV infection, or their combination. In addition, soluble factors in the supernatants obtained from mixed lymphocyte cultures containing alcohol-treated DCs or DCs obtained from HCV-infected patients could transfer inhibition of T-cell proliferation in cultures containing DCs obtained from healthy volunteers. Anti–IL-10 neutralizing antibody ameliorated the reduced mixed lymphocyte reaction containing DCs obtained from HCV-infected patients, whereas exogenous IL-12, but not anti–IL-10, treatment ameliorated the reduced T-cell proliferation induced by alcohol treatment of DCs obtained from healthy volunteers. The results support the suggestion that both acute alcohol intake and in vitro alcohol treatment inhibit DC antigen-presenting cell function and support the hypothesis that viral factors interact with alcohol to reduce DC functions in HCV infection. NIAAA Glossary Terms:  ethanol, immunosuppressive effect, immune response, monocyte, dendrite, T lymphocyte, hepatitis C, viral disease, lipopolysaccharide, cell culture study, human study, controlled study, cytokines, interleukin, hypothesis testing, in vitro study, conference proceedings

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Wilza A.F. Peres, Maria G.T. Carmo, Sérgio Zucoloto, Antonio C. Iglesias, and Valeria B. Braulio.  Ethanol intake inhibits growth of the epithelium in the intestine of pregnant rats.  Alcohol 33(2):83-89, June 2004.

Summary: This study investigated the effects of ethanol ingestion on jejunal and ileal epithelial cells in pregnant rats. Timed-pregnancy female rats were fed a liquid diet containing either ethanol or an isocaloric amount of carbohydrate (the pair-fed group) from gestational day 2 up to delivery. Daily diet ingestion, body weight, nitrogen balance, and nitrogen digestibility were assessed during the gestational period. Crypt and villus cell population, crypt cell proliferation, and crypt cell cycle time were measured in the maternal small intestine at the time animals were killed, just after delivery. Ethanol consumption resulted in ileal hypoplasia of the crypt and villus, but only the villus showed hypoplasia in the jejunum. In addition, crypt cell proliferation was markedly decreased, whereas crypt cell cycle time was longer in both the jejunum and ileum of the ethanol-fed group. Ethanol ingestion had no significant effect on body weight gain, nitrogen balance, and nitrogen digestibility. As expected, the offspring from the ethanol-fed group had significantly lower body weight. In conclusion, chronic ethanol ingestion during pregnancy inhibited the maternal intestinal epithelium growth, more extensively in the ileum. NIAAA Glossary Terms:  small intestine, pregnancy, ethanol, AOD consumption, chronic AODE, animal study, laboratory rat, body weight, nitrogen, diet, digestion, digestive system disorder, controlled study

Pedro Rada, Nicole M. Avena, Sarah F. Leibowitz, and Bartley G. Hoebel.  Ethanol intake is increased by injection of galanin in the paraventricular nucleus and reduced by a galanin antagonist.  Alcohol 33(2):91-97, June 2004.

Ethanol intake stimulates expression of galanin in the hypothalamus, including the paraventricular nucleus. Injection of galanin in the paraventricular nucleus induces eating; this study tested the hypothesis that galanin injection might also affect ethanol intake. Rats were given ad libitum access to 4% ethanol for 4 weeks and assigned to one of two groups based on ethanol consumption level: high levels (>1.5 g/ kg/day) or low levels (<1.0 g/kg/day). In Experiment 1, galanin (1.0 nmol) or Ringer's solution was injected unilaterally into the paraventricular nucleus, with food and water absent during the first 4 hours. Galanin significantly increased ethanol intake only in rats that drank high levels of ethanol. In Experiment 2, injection of galanin (0.5 and 1.0 nmol) in the paraventricular nucleus dose-dependently increased ethanol intake with food and water available. The higher dose was also effective in eliciting ethanol intake when tested with food and water absent. In Experiment 3, a test of receptor specificity was provided by injecting rats with the galanin antagonist M-40 (0.5 nmol) or Ringer's solution. Injection of M-40 in the paraventricular nucleus significantly decreased ethanol consumption. In Experiment 4, an anatomic control, with galanin injected 2 mm dorsal to the paraventricular nucleus in the same animals, caused no change in ethanol intake. In conclusion, injection of galanin in the paraventricular nucleus, at a dose known to induce feeding, acted by means of a galanin receptor to potentiate intake of 4% ethanol, even with food and water available as alternate sources of calories and fluid. Because ethanol can increase expression of galanin mRNA in the paraventricular nucleus, this could set the stage for a positive feedback loop between galanin and ethanol intake. NIAAA Glossary Terms:  hypothalamus, paraventricular nucleus, ethanol, AOD consumption, AOD intake per occasion, receptors, antagonists, hypothesis testing, dose-response relationship, mRNA, biological feedback, controlled study, animal study, laboratory rat

Cindy L. Ehlers, Evelyn Phillips, and Marc A. Schuckit.  EEG alpha variants and alpha power in Hispanic American and white non-Hispanic American young adults with a family history of alcohol dependence.  Alcohol 33(2):99-106, June 2004.

Summary: Several studies support associations among variants in electroencephalogram (EEG) alpha voltage, alcohol dependence, ethnic background, and a family history of alcohol dependence, although no studies have as yet been conducted in individuals of Hispanic ethnicity. This study categorized EEG, by using spectral analyses, into high-, medium-, and low-voltage alpha, as well as absolute EEG power in alpha and beta frequency ranges, in Hispanic American (n = 108) and white non-Hispanic American (n = 269) young adult men and women (age range, 18 to 25 years) who had a family history, but no personal history, of alcohol dependence. Eighteen percent (n = 70) of the participants had a low-voltage alpha EEG, 16% had high-voltage alpha, and 64% had medium-voltage alpha. In comparison with findings for men, women were found to have higher overall power in the low frequency alpha (7.5–9 Hz) and beta (12–20 Hz, 20–50 Hz) frequency ranges. Hispanic Americans had a lower percentage of individuals in the low-voltage alpha group (9%) and more individuals in the medium-voltage alpha group (73%) compared with findings for white non-Hispanic Americans (low-voltage alpha, 19%; medium-voltage alpha, 62%). These results confirm the presence of ethnic stratification in EEG alpha variants. NIAAA Glossary Terms:  electroencephalography, brain wave, ethnic group, Hispanic, White American, ethnic differences, AOD dependence, familial alcoholism, genetic markers, gender differences, human study

Richard L. Bell, Zachary A. Rodd, Cathleen C. Hsu, Lawrence Lumeng, Ting-Kai Li, James M. Murphy, and William J. McBride.  Effects of concurrent access to a single concentration or multiple concentrations of ethanol on ethanol intake by periadolescent high-alcohol-drinking rats.  Alcohol 33(2):107-115, June 2004.

Summary: The effects of access to different concentrations of ethanol and the sex of the animal on ethanol consumption were assessed in adolescent high-alcohol-drinking (HAD-1 and HAD-2) rats. At the beginning of adolescence (postnatal day 30), the rats were given concurrent access to either a single concentration (15% v/v) or multiple concentrations (10%, 20%, and 30% v/v) of ethanol and water. Analyses of ethanol consumption data revealed significant (P < 0.025) main effects of line, ethanol condition, and week, and a significant line by sex by ethanol condition by week interaction. For the first week, both male and female HAD-1 and HAD-2 rats consumed more ethanol under the multiple ethanol concentration condition than under the single ethanol concentration condition. However, across the second through fourth weeks, this pattern was seen primarily in male and female HAD-1 rats and to a lesser degree in female HAD-2 rats. In general, female rats consumed more fluids compared to male rats, and male rats displayed a higher preference for ethanol over water ratio than their female counterparts. In addition, in comparison with HAD-2 rats, HAD-1 rats drank more ethanol and displayed a higher preference for ethanol ratio. Overall, the results of this study indicate that, compared with access to a single concentration (which is used in most studies), concurrent access to multiple concentrations of ethanol produced significantly higher ethanol intakes in periadolescent HAD rats, supporting the suggestion that this ethanol drinking condition would have a greater impact on neuronal development. In addition, although the replicate lines were selectively bred by using the same criteria and foundation stock, the higher ethanol intakes of the HAD-1 line, compared with intakes for the HAD-2 line, seen in the current study support the suggestion that there are some differences in their genetic make-up, affecting ethanol intake, which are expressed during periadolescence. NIAAA Glossary Terms:  animal selectively bred for AOD preference, AOD preference, laboratory rat, adolescent, ethanol, AOD consumption, AOD intake per occasion, gender differences, genetic theory of AODU, genetic trait, animal study, comparative study

Marisela Hernández-González, Koral Elizabeth Rivera Sánchez, Martha Verónica Oropeza Blando, Sandra Orozco-Suarez, Marcela Arteaga Silva, Miguel Angel Guevara.  Effects of alcohol on behavioral and morphologic indices of sexual maturation in male rats.   Alcohol 33(2):117-126, June 2004.

Summary: Studies support the suggestion that alcohol treatment after weaning delays the onset of puberty and decreases weight of sex organs of male rats. The effect of alcohol on other morphologic and behavioral indices related to sexual maturation has not been evaluated. In this study, chronic consumption of alcohol (6% ethanol) in male rats, from weaning to 47 days of age, increased the occurrence of genital grooming and spontaneous penile erections and of preputial separation, but had no effect on sex organ weight or penile spine number. Findings from this study reflect that alcohol's effects on the morphologic and behavioral indices of sexual maturation are distinct and emphasize the importance of studying critical peripubertal ages after chronic exposure to alcohol. NIAAA Glossary Terms:  puberty, sexual behavior, morphology, ethanol, AOD consumption, chronic AODE, animal study, laboratory rat, male, biological maturation

Frédéric Lamarche, Nathalie Signorini-Allibe, Brigitte Gonthier, and Luc Barret.  Influence of vitamin E, sodium selenite, and astrocyte-conditioned medium on neuronal survival after chronic exposure to ethanol.  Alcohol 33(2):127-138, June 2004.

Summary: The authors investigated the ability of hydrosoluble vitamin E (trolox), sodium selenite, and astrocyte-conditioned medium to protect cultured rat neurons against ethanol-induced oxidative stress after chronic exposure to ethanol. When a 6-day exposure to ethanol (20 mM) led to a loss of cell viability, the presence of trolox (10 μM) provided significant neuroprotection. In the presence of the catalase inhibitor 3-amino-1,2,4-triazole, which created conditions that were favorable to reactive oxygen species accumulation, trolox was able to counteract the deleterious effect of the inhibitor. Moreover, flow cytometric analysis indicated that trolox can maintain the intracellular glutathione content in neurons chronically exposed to ethanol. In these conditions of exposure, the absence of sodium selenite in the culture medium significantly aggravated the exposure-induced effects, whereas sodium selenite (100 nM) offered a significant neuroprotection. Finally, the presence of 25% astrocyte-conditioned medium in the culture medium induced a neuroprotective effect in the presence of ethanol. Nevertheless, when astrocytes were previously chronically (3 days) exposed to ethanol, their culture medium did not offer a significant protection. These results provide evidence that vitamin E and astrocytes can protect neurons from ethanol-induced oxidative stress, notably by helping to maintain intracellular glutathione levels. Selenium, by means of its exogenous addition in the form of sodium selenite, also had an interesting neuroprotective effect. NIAAA Glossary Terms:  vitamin E, astrocyte, selenium, protective factors, neuron,  cell culture study, animal study, laboratory rat, ethanol, oxidative stress, chronic AODE, catalase, enzyme inhibitors, glutathione, oxygen radicals, free radicals

Theresa W. Gauthier, Martha H. Manar, and Lou Ann S. Brown.  Is maternal alcohol use a risk factor for early-onset sepsis in premature newborns?  Alcohol 33(2):139-145, June 2004.

Summary: The hypothesis that maternal alcohol use during pregnancy would increase the risk of sepsis in very low birth weight (VLBW) premature newborns was tested in a case-control study of VLBW newborns born at Grady Memorial Hospital (Atlanta, GA). Alcohol exposure, as the predictive variable, was assessed by maternal self-report. The outcome variables were early-onset and multiple late-onset sepsis. Univariate analysis with Fisher exact test and multivariate analysis with the use of binary logistic regression were performed. Early-onset sepsis was 15-fold higher in the alcohol-exposed group (n = 20) compared to the matched control group (n = 168) (alcohol-exposed group, 10%, vs. control group, 0.6%: odds ratio [OR] = 6.8; 95% confidence interval [CI], 2.7-17.1; p ≤ 0.05). Early-onset sepsis in the alcohol+cocaine-exposed group (n = 64) did not differ from findings for the control group. The prevalence of multiple late-onset sepsis did not differ among the exposure groups. Logistic regression analysis, controlling for chorioamnionitis and premature prolonged rupture of membranes, demonstrated an independent, increased risk of early-onset sepsis with alcohol exposure [OR = 16; 95% CI, 1.2-210), p ≤ 0.05]. In conclusion, alcohol exposure significantly increased the risk of early-onset sepsis in this group of VLBW newborns. The effects of maternal alcohol abuse during pregnancy on the risk of infection in the VLBW newborn require further analysis. NIAAA Glossary Terms:  prenatal alcohol exposure, AOD consumption, self-report, neonate, infection, immune response, immune disorder, developmental disorder, cocaine, multiple drug use, prevalence, early disease onset, regression analysis, risk factors, risk analysis, relative risk, case-control study, human study

Stephen B. Pruett, Qiang Zheng, Ruping Fan, Kametra Matthews, and Carlton Schwab.  Ethanol suppresses cytokine responses induced through Toll-like receptors as well as innate resistance to Escherichia coli in a mouse model for binge drinking.  Alcohol 33(2):147-155, June 2004.

Summary: Toll-like receptors (TLRs) recognize molecular patterns associated with pathogens and initiate various mechanisms that are critical in innate resistance to infection. It has been reported that acute administration of ethanol suppresses responses mediated through TLR3 and TLR4, but it is not known if this is also true for other TLRs. This study used ligands for TLR2/TLR6 (zymosan A), TLR5 (bacterial flagellin), TLR7 (R-848), and TLR9 (CpG DNA) to induce cytokine production in mice, and the effects of ethanol (6 g/kg by gavage) on this induction were determined. Because different cell types may be affected differently by ethanol, cytokines were measured in serum (as an indication of cytokines produced by a number of different cell types) and in peritoneal lavage fluid (as an indicator of cytokine production primarily by peritoneal macrophages). Ethanol significantly affected the concentration of at least one of the cytokines evaluated in serum or peritoneal lavage fluid [interleukin (IL)-6, IL-10, and IL-12 p40 subunit] induced by all TLR ligands tested. The results also supported the suggestion that serum and peritoneal cytokines were mostly derived from different cells types, which were affected differently by ethanol. To determine whether ethanol-induced changes in TLR responses were associated with suppression of innate resistance to infection, a model of experimental peritonitis with a nonpathogenic (indigenous) strain of Escherichia coli was developed. Ethanol significantly decreased host resistance to E. coli peritonitis. Thus, ethanol suppresses responses induced by TLR receptors in mice and in the same experimental system it suppresses resistance to infection. NIAAA Glossary Terms:  cytokines, receptors, ligand, receptor ligand binding, interleukin, interleukin-8, peritoneum, serum, infection, bacteria, peritonitis, abdomen, macrophage, animal study, laboratory mice

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T. Edward Orr, Jennifer L. Whitford-Stoddard, and Ralph L. Elkins.  Taste-aversion-prone (TAP) rats and taste-aversion-resistant (TAR) rats differ in ethanol self-administration, but not in ethanol clearance or general consumption.  Alcohol 33(1):1-7, May 2004.

Summary: Rats selectively bred for proneness or resistance to alcohol taste aversion (TAP and TAR rats respectively) consume widely different amounts of alcohol. Blood alcohol concentrations (BACs) in TAP and TAR rats were measured after 9 days of limited (2 hours/day) access to a simultaneous, two-bottle choice of 10% ethanol (v/v) or plain water.  Ethanol intakes and BACs were highly correlated among TAR rats. The comparison could not be made with TAP rats, because not enough them yielded measurable BACs. The same rats were then exposed to 24-hours/day access to a two-bottle choice (10% ethanol or plain water) for 8 days. Ethanol consumption during the continuous access period correlated highly with that observed during limited access. Subsequent tast-aversion conditioning with these rats yielded differences in saccharin preferences characteristic of each rat line. A separate group of TAP and TAR rats was used to determine ethanol clearance by measuring BACs at 1, 4, and 7 hours after injection of a 2.5-g/kg dose of ethanol. The two rat lines did not differ in ethanol clearance nor in food and water consumption. Thus the differences in ethanol consumption in TAP and TAR rats cannot be attributed to line differences in ethanol metabolism or in general consummatory behavior. The authors state that the results support their contention that the differences in ethanol consumption in these two rat lines are mediated by differences in mechanisms related to taste aversion. They discuss the findings with respect to genetically based differences in the subjective experience of ethanol.

Diego A. Rodriguez, Claudio Moncada, Marco T. Núñez, Sergio Lavandero, Biddanda C. Ponnappa, and Yedy Israel.  Ethanol increases tumor necrosis factor-alpha receptor-1 (TNF-R1) levels in hepatic, intestinal, and cardiac cells.  Alcohol 33(1):9-15, May 2004.

Summary: Binding of tumor necrosis factor-alpha (TNF-α) to TNF-α receptor-1 (TNF-R1) activates mechanisms that lead to necrosis and apoptosis in most tissues and also increases the expression of inflammation-promoting intercellular adhesion molecules (ICAM). This study examined whether ethanol exposure leads to increases in cellular TNF-R1. HepG2 human hepatoma cells and H4-II-E-C3 rat hepatoma cells were incubated with 25, 50, and 100 mM ethanol for various periods up to 48 hours. Human colonic adenocarcinoma cells (Caco-2 cells) and neonatal rat primary cardiomyocytes were also incubated with various concentrations of ethanol. Levels of TNF-R1 were measured either by a sandwich enzyme-linked immunosorbent assay (ELISA) or by determining the extracellular transmembrane domain of TNF-R1 by an intact-cell ELISA method. Ethanol exposure for 48 hours dose-dependently increased TNF-R1 levels in human hepatoma cells. Levels increased significantly by 164% at 50 mM and by 240% at 100 mM ethanol. Effects were time dependent and did not level off at 48 hours. Similar increases in TNF-R1 were also observed in rat hepatoma cells (90% at 50 mM and 230% at 100 mM ethanol). Under similar conditions, Caco-2 cells showed a significant 80% increase in TNF-R1 levels at 200 mM ethanol, a concentration found in intestine. Neonatal rat primary cardiomyocytes showed TNF-R1 increases of 36% at 50 mM and 44% at 100 mM ethanol. The results indicate that TNF-R1 levels are increased by exposure of different cell types to pharmacologic concentrations of ethanol. The  increase may augment TNF-α-mediated cell injury in different tissues.

Deaciuc IV, Arteel GE, Peng X, Hill DB, and McClain CJ.  Gene expression in the liver of rats fed alcohol by means of intragastric infusion.  Alcohol 33(1):17-30, May 2004.

Summary: Complementary DNA (cDNA) microarray technology was used to assess possible changes in the expression of a large number of genes in the liver of rats fed ethanol for 4 weeks by intragastric infusion, an animal model that closely resembles alcoholic liver disease in humans. Of a total of 8,740 probe sets arrayed on the microchip, 2,069 were expressed by the liver. After correction for a 10% false discovery rate, 72 genes were found to be either significantly up-regulated (n = 40) or down-regulated (n = 32). Forty-two genes were suppressed and 4 genes were induced by alcohol. These genes are involved in a wide range of cellular functions. The genes that were significantly changed were categorized into two groups: those that have been implicated in alcoholic liver disease and those that have not been tested for possible changes in expression. Large-scale gene profiling of the liver reveals changes in the expression of a number of genes that have never been implicated in alcohol-induced injury. The authors suggest that further study of such genes may cast light on mechanisms underlying alcohol-induced liver injury and help in the design of new therapeutic approaches.

Roman E, Ploj K, and Nylander I.  Maternal separation has no effect on voluntary ethanol intake in female Wistar rats.  Alcohol 33(1):31-39, May 2004.

Summary: Short and prolonged periods of maternal separation during the postnatal period have been shown to increase voluntary ethanol intake in male rats, and recent studies indicate sex differences in the effects of maternal separation. This study examined the effects of maternal separation on acquisition of voluntary ethanol intake in female Wistar rats. Rat pups were subjected to daily maternal separation for 15 minutes (MS15) or 360 minutes (MS360) during the first 3 weeks of life or reared under normal animal facility rearing (AFR) conditions. Starting at 10 weeks of age, the effects of maternal separation on acquisition of voluntary ethanol intake were investigated for 25 days. In contrast to previous results with male rats, neither MS15 nor MS360 affected acquisition of voluntary ethanol intake in female rats. A stressful situation in adulthood, restraint stress, significantly increased ethanol intake during the restraint period compared with baseline levels in the animals reared under normal AFR conditions, an effect that persisted throughout the postrestraint period. In rats subjected to MS15 or MS360, a significant increase in ethanol intake was shown during the postrestraint period compared with baseline levels. The findings in this study provide further evidence of sex differences in the consequences of maternal separation. Compared with previous findings in male rats, acquisition of ethanol intake was not affected, and restraint-induced effects were less pronounced but more prolonged, in female rats.

Smith SS, Ruderman Y, Hua Gong Q, and Gulinello M.  Effects of a low dose of ethanol in an animal model of premenstrual anxiety.  Alcohol 33(1):41-49, May 2004.

Summary: The acoustic startle response (ASR) and elevated plus-maze behavioral models were used to test the hypothesis that the anxiolytic effect of ethanol exhibits a dose-response effect after withdrawal from progesterone in a rodent model of premenstrual anxiety. Adult female rats were tested either 24 hours after removal of a progesterone-filled capsule implanted subcutaneously for 21 days (progesterone withdrawal) or on the day of diestrus, a low hormone state. Low doses of ethanol (0.2–0.4 mg/kg) produced a significant 60%-70% decrease in the ASR only in animals undergoing progesterone withdrawal. However, higher doses of ethanol (0.8–1.2 g/kg) were ineffective in these animals, resulting in an “inverted U” ethanol dose effect similar to that observed at recombinant α4β2δ subunit combinations of the GABAA receptor. Consistent with these findings, there was also a significant 70% attenuation of the ASR after progesterone withdrawal with 3 mg/kg of THIP, a GABAA receptor partial agonist with greater potency at α4βδ receptors than at other known isoforms. THIP was not anxiolytic in control animals. The results support the suggestion that ethanol in very low doses is anxiolytic in a model of premenstrual anxiety, whereas higher, potentially sedative, doses are without effect. The results may be relevant for altered ethanol sensitivity during premenstrual syndrome, when increased ethanol consumption has been reported.

Sable HJK, White SL, and Steinpreis RE.  Effects of chronic naltrexone treatment in rats on place preference and locomotor activation after acute administration of cocaethylene or ethanol plus cocaine.  Alcohol 33(1):51-61, May 2004.

Summary: Investigators have demonstrated that cocaine, ethanol, and cocaethylene (the cocaine metabolite produced when cocaine and ethanol are taken together) all produce a conditioned place preference when administered intraperitoneally. Based on moderate success with naltrexone in attenuating the rewarding effects of ethanol and cocaine administered independently, the authors of this study examined the ability of chronic naltrexone treatment (administered by subcutaneous implant across 6 days) to reduce the preference and motor-stimulating effects resulting from intraperitoneal administration of cocaethylene (Experiment 1) and the co-administration of ethanol with cocaine (Experiment 2) in outbred rats. Naltrexone modestly reduced conditioned place preference for cocaethylene but had no effect on the locomotor stimulation resulting from cocaethylene administration. Naltrexone failed to decrease the preference for the chamber paired with co-administration of ethanol and cocaine and did not change the degree of locomotor activation produced by these drugs. The results support the suggestion that naltrexone as a pharmacotherapy to treat co-abuse of ethanol and cocaine in human beings may have limited benefits.

Crews FT, Nixon K, and Wilkie ME.  Exercise reverses ethanol inhibition of neural stem cell proliferation.  Alcohol 33(1):63-71, May 2004.

Summary: Learning, an enriched environment, and exercise all increase neural stem cell proliferation in the hippocampus and improve performance on learning tests, whereas acute ethanol consumption decreases neural stem cell proliferation in the hippocampus. This study explored the interaction of exercise and ethanol consumption in C57BL/6 mice that were given access to ethanol, a running wheel, or both, and investigated neural stem cell proliferation in the hippocampal dentate gyrus, corpus callosum, and forebrain subventricular zone in each group of mice. Mice with access to ethanol consumed large amounts of it; mice given access to a running wheel ran long distances; and the combined groups' behavior was comparable to that of the ethanol access alone group and of the running wheel access alone group. Neural stem cell proliferation was assessed by treating mice with bromodeoxyuridine (12 days, 300 mg/kg/day, i.p.) and evaluating consequent immunoreactivity. Exercise increased bromodeoxyuridine immunoreactivity in dentate gyrus, but not in other brain regions studied. Self-administration of ethanol decreased bromodeoxyuridine immunoreactivity by approximately 60% (p < .01) in dentate gyrus, 70% (p < .001) in forebrain, and 80% (p < .001) in corpus callosum. Findings for exercise and ethanol consumption combined were remarkably similar to those for exercise alone. The opposing effects of ethanol consumption and exercise on neurogenesis could contribute to the central nervous system pathology and health benefits, respectively, of these two behaviors.

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