Alcoholism Clinical and Experimental Research

Published by Wiley
Online ISSN: 1530-0277
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Article
The Chinese herbal medicine, NPI-028, has been used for centuries in China to counteract alcohol intoxication. The present study used a number of different experimental conditions to determine whether NPI-028 and its derivatives might selectively influence alcohol intake in rodents that naturally exhibit high alcohol intakes. It was determined that intraperitoneal (i.p.) injections of NPI-028 (0.5, 0.75, and 1.0 g/kg) suppressed alcohol intake by up to 30% in both alcohol-preferring P and Fawn-Hooded (FH) rats during a continuous access schedule. These injections did not significantly affect food or water intakes, nor did the highest dose of NPI-028 (1 g/kg) alter blood ethanol levels after an i.p. injection of 2.5 g/kg of ethanol. In P rats, it was found that NPI-028 was orally active with the dose of 1.5 g/kg having a greater effect on ethanol intake than the 1.0 g/kg dose; once again, food and water intakes were not significantly altered. In FH rats maintained on a limited access schedule (1 hr/day), alcohol intake was completely abolished by 1.5 g/kg of NPI-028. Chronic i.p. administration of NPI-028 (0.75 g/kg) for four consecutive days in FH rats maintained on a continuous access schedule did not lead to any diminution of its alcohol-suppressant effects. Thus, NPI-028 has significant effects on alcohol intake without much effect on water and food intake, and tolerance does not readily develop to these effects. The i.p. administration of a partially purified extract (NPI-031) of NPI-028, obtained by countercurrent chromatography, also dose-dependently suppressed ethanol intake in FH rats, but the highest dose 200 mg/kg) also significantly decreased food intake. Finally, the i.p. administration of puerarin (NPI-31G), an isoflavone isolated from NPI-031 by countercurrent chromatography, significantly reduced ethanol intake in FH rats without affecting food or water intake. Therefore, NPI-028 and one of its pure components, NPI-031G, selectively reduced ethanol intake in alcohol-preferring rats.
 
Article
In a previous study, we showed that a single injection of the thyrotropin-releasing hormone analog TA-0910 dose-dependently reduced alcohol intake in alcohol-preferring (P) rats and increased their water intake over a 24-hr period. In the present study, the effects of seven consecutive, once-daily injections of TA-0910 (0.75 mg/kg, ip) on alcohol preference were determined. P rats developed tolerance to the attenuating effects of TA-0910 on alcohol intake within 3-5 days. Following the development of tolerance to TA-0910, rats were injected with the dopamine agonist bromocriptine (0.5 mg/kg, sc). In the presence of tolerance to TA-0910, the attenuating effect of bromocriptine on alcohol intake was reduced. When rats were made tolerant to the attenuating effects of bromocriptine, they exhibited tolerance to the attenuating effects of TA-0910. These findings indicate that tolerance to the effects of TA-0910 on alcohol intake occurs and suggest dopamine involvement in the mechanism of action of TA-0910 in reducing alcohol intake in P rats.
 
Article
In previous studies, we found that single injections of the thyrotropin-releasing hormone analog TA-0910 dose-dependently reduced alcohol intake and preference in alcohol-preferring (P) and Fawn-Hooded (FH) rats over a 24-hr period of continuous access to alcohol and water. However, several consecutive daily injections of TA-0910 resulted in the development of tolerance to these effects. In the present study, we found that in a 5-hr limited-access schedule in which monkeys could select an aqueous alcohol solution (7.5% v/v) or tap water, single doses of TA-0910 (0.0625, 0.125, 0.25, 0.5, and 0.75 mg/kg), similar to those found effective in P and FH rats, reduced consumption of alcohol. In this protocol, tolerance to the attenuating effects of TA-0910 on alcohol intake was not evident after five consecutive once-daily doses of 0.5 mg/kg. Furthermore, it was shown that a single dose of 0.75 mg/kg TA-0910 did not significantly influence 24-hr water intake when water was the only available fluid, but did reduce the intake of a preferred solution of saccharin. These findings suggest that activation of brain thyrotropin-releasing hormone systems reduces alcohol intake in primates and that tolerance to this effect is not evident within 5 days under a limited access schedule.
 
Article
Pharmacological experiments were conducted to determine the neuronal mechanisms involved in the suppressive effects of the thyrotropin-releasing hormone analog TA-0910 on alcohol intake in alcohol-preferring (P) rats. We previously reported that single intraperitoneal injections of TA-0910 dose-dependently reduced alcohol intake in P rats without altering fluid or total calorie intake; however, after several consecutive, once-daily injections, P rats developed tolerance to the suppressive effects of TA-0910 on alcohol intake and cross-tolerance to like effects of the dopamine D2 agonist bromocriptine, but not to like effects of the serotonin uptake inhibitor fluoxetine. In the present study, rats were injected with vehicle or different doses of the D2 antagonist s(-)-eticlopride (0.01 to 0.05 mg/kg) or the D1 antagonist R(+)-SCH23390 (0.1 to 0.5 mg/kg) and 20 min later with TA-0910 (0.75 mg/kg). Alcohol and water intakes were measured at 2, 4, 6, and 24 hr, and food was measured every 24 hr. Both s(-)-eticlopride and R(+)-SCH23390 produced modest reductions in alcohol intake alone; however, only s(-)-eticlopride antagonized the suppressive effect of TA-0910 on alcohol intake. In related experiments, it was confirmed that the dopamine D3 agonist 7-hydroxy-N,N-di-n-propyl-2-aminotetralin reduced alcohol intake in P rats, and it was found that tolerance to this effect did not develop during or after seven consecutive once-daily injections. Furthermore, this effect of 7-hydroxy-N,N-di-n-propyl-2-aminotetralin was not diminished in rats made tolerant to the effect of TA-0910 on alcohol intake. These data, those of previous studies, and recent preliminary findings support involvement of dopamine D2, but not D1 or D3 receptors in mediating the suppressive effect of TA-0910 on alcohol intake of P rats.
 
Article
Experiments were performed to characterize the acute effect of different doses of a novel thyrotropin-releasing hormone (TRH) analogue (TA-0910) on ethanol intake in rats. Selectively bred alcohol-preferring (P) rats received a single intraperitoneal injection of normal saline or 0.083, 0.25 and 0.75 mg/kg of TA-0910 at 9:30 AM, and their consumption of ethanol, water, and food was measured for 24 hr. TA-0910 dose-dependently attenuated ethanol intake and commensurately increased water consumption. Only the highest dose of TA-0910 increased the total caloric intake. TA-0910 did not affect the pharmacokinetics of ethanol. These findings indicate involvement of TRH systems in ethanol preference and suggest that centrally acting TRH analogues may be therapeutic in the treatment of alcoholism.
 
Article
The pathogenetic correlation between chronic alcohol consumption and development of colon cancer is not clear. The role of alcohol abuse in the carcinogenic action of 1,1-dimethylhydrazine (DMH), which induces tumors in the colon, was evaluated. Twenty male rats were fed liquid diets containing ethanol or carbohydrates for 39 weeks. DMH (20 mg/kg body weight, once a week) was injected subcutaneously from the 5th to the 20th week. Pair feeding was stopped at 10:00 am and DMH was administered at 02:00 pm. Ethanol was not detected in the blood at the time of injection. Liquid diets were provided again at 05:00 pm until 10:00 am next day. The animals were killed at the end of the 39th week, and the colons were removed for examination for the number of aberrant crypt foci (ACF) by methylene blue staining. Tissue sections were stained for histology and cytochrome P4502E1 (CYP2E1) expression. The number of ACF in colons obtained from ethanol-fed rats with DMH was 24 (n=5, 4.4+/-2.5/rat), which was significantly (p<0.001) more than that of the other treated rats: only 3 (n=5, 0.6+/-0.5/rat) in the pair-fed control rats with DMH, and none in the ethanol-fed or control-fed rats without DMH. Cytochrome P4502E1 staining demonstrated marked expression in the colon mucosa from ethanol-fed rats, but not in the pair-fed control rats. The increased expression of CYP2E1 induced by chronic ethanol consumption promotes the development of DMH-induced colon cancer.
 
Article
The role of brain catalase in the mediation of ethanol's effects on motor activity was investigated. Male Long-Evans rats were pretreated with i.p. injections of the catalase inhibitor, 3-amino-1,2,4-triazole (AT) (1 g/kg) or saline (S). Four hours later, animals in each group received i.p. injections of one of two doses of ethanol (ETOH) [1.0 g/kg (E1) or 2.0 g/kg (E2)] or one of two volumes of distilled water (W1 or W2). Ten minutes after the administration of these agents, animals were placed in open-field chambers and motor activity was recorded during a 10-min testing period. Results indicated that the motor depression produced by 2.0 g/kg of ETOH was significantly attenuated in AT pretreated rats (group AT-E2). AT pretreatment, however, had no effect on motor activity for subjects injected with 1.0 g/kg ethanol or water. Total brain catalase activity in AT-pretreated animals was 15% of control animals. No differences in blood ethanol levels were observed between AT- and S-pretreated animals. An interaction between ethanol and AT at the level of the central nervous system is suggested. The results of the present study suggest that brain catalase activity may be involved in ethanol's effects. They also provide further support for the notion that acetaldehyde may be produced directly in the brain via catalase and that it may be a factor mediating some of ethanol's central effects.
 
Article
The hydrolysis of membrane phosphoinositides is widely recognized as an important signal transduction pathway in brain. One of the products of phosphoinositide hydrolysis, Ins(1,4,5)P3, is thought to participate in signal transduction by mobilizing intracellular calcium and it is now clear that Ins(1,4,5)P3 metabolism is a complicated process that may be highly regulated. In addition to being dephosphorylated by the action of a 5-phosphatase, Ins(1,4,5)P3 can be phosphorylated by a 3-kinase to Ins(1,3,4,5)P4. Although the physiological significance of the higher inositol polyphosphates is not clear, recent evidence suggests that Ins(1,3,4,5)P4 may also have important second messenger function. Since ethanol is known to have potent effects on synaptic transmission, we investigated the in vitro effects of ethanol on [3H]Ins(1,3,4,5)P4 metabolism by rat whole brain homogenates. Ins(1,3,4,5)P4 was rapidly hydrolyzed to Ins(1,3,4)P3, inositol bisphosphates [Ins(3,4)P2 and Ins(1,3)P2], inositol monophosphates [Ins(1)P/Ins(3)P and Ins(4)P], and to inositol by sequential dephosphorylation. No [3H]Ins(1,4,5)P3 was detected. Ethanol (500 mM), significantly accelerated the dephosphorylation of Ins(1,4,5)P3, resulting in a more rapid formation of inositol bisphosphates, monophosphates and inositol. However, intoxicating and sedative-hypnotic concentrations of ethanol (30-100 mM) had no effect upon Ins(1,3,4)P3 dephosphorylation, suggesting that pharmacologically relevant concentrations of ethanol do not directly effect the enzymes involved in the dephosphorylation of Ins(1,3,4,5)P4 to free inositol in brain.
 
Article
We have previously demonstrated that chronic ethanol specifically decreases the hepatic level and rate of synthesis of 2,6-sialyltransferase (2,6-ST). To understand its mechanism of action, effects of 8 weeks of chronic ethanol feeding on the expression of sialyltransferase (ST) genes in rat liver and kidneys were determined by Northern-blot analysis of ST mRNAs. It was found that, compared with the pair-fed control rats, the percentage decreases in ST mRNAs in the ethanol-fed group were as follows: liver-Gal-beta-1,4GlcNAc alpha 2,6-ST (2,6-ST): 59% (p < 0.001); liver-Gal-beta-1,3GlcNAc alpha 2,3-ST (2,3-ST): 32% (p < 0.01); and kidneys-2,6-ST: 5% (NS). In contrast, glyceral-dehyde-3-phosphate dehydrogenase mRNA in both liver and kidneys was unaffected by the same ethanol treatment. Taken together, these results demonstrate that chronic ethanol downregulates the expression of 2,6-ST and 2,3-ST genes in rat liver.
 
Article
The simultaneous administration of ethanol increases the mortality rate and tissue damage observed in rats after 1,4-butanediol (1,4-BD). A related increase in tissue 1,4-BD concentration supported the hypothesis of an in vivo competition of the two substances for alcohol dehydrogenase. The clinical implications of the results, in light of the recent discovery of the presence of endogenous 1,4-BD in humans are discussed.
 
Article
The effect of oxidized and reduced glutathione on inositol 1,4,5-trisphosphate (InsP3)-induced Ca2+ release from endoplasmic reticular Ca2+ stores was studied in digitonin-permeabilized hepatocytes from chronically ethanol-fed rats and pair-fed control animals. The fractional Ca2+ release induced by a subsaturating concentration of InsP3 was significantly enhanced in cells from ethanol-fed rats in the absence of a change in maximal InsP3-releasable Ca2+ pool size, and this difference was not affected by preincubation with reduced glutathione. Incubation with oxidized glutathione (1 mM) increased the efficacy of Ca2+ release by subsaturating concentrations of InsP3 in both control preparations and in cells from ethanol-fed rats. The shift in the InsP3 dose-response curve was not significantly different between the two preparations. These findings suggest that the enhanced efficacy of InsP3-induced Ca2+ release in hepatocytes from ethanol-fed rats is not caused by the oxidation of protein-bound thiol groups on the InsP3 receptor.
 
Article
Although ethanol is known for its central depressant action, its effect on the polyphosphoinositide (poly-PI) signal transduction activity in brain has not been examined in detail. In this study, C57Bl/6J mice were injected intracerebrally with [3H]inositol, and poly-PI turnover in brain was assessed by determining the levels of labeled inositol monophosphates (IP1) accumulated after intraperitoneal injection of LiCl (6 meq/kg body weight) 4 hr before killing. Using this experimental protocol, acute ethanol administration (by gavage) resulted in time- and dose-dependent decreases in the levels of labeled IP1 in both cerebrum and cerebellum as compared with controls. The ethanol-induced decrease in labeled IP1 correlated well with the decrease in levels of inositol 1,4,5-triphosphate (as measured by the radioreceptor assay) and the increase in blood ethanol concentration. Despite a 4-fold higher accumulation of labeled IP1 in the cerebrum compared with the cerebellum, there were no major differences in the steady-state levels of inositol 1,4,5-triphosphate (based on tissue weight) in either brain region. Intraperitoneal injection of atropine (50 mg/kg) (a muscarinic cholinergic receptor antagonist) to the lithium-treated mice resulted in a 34% decrease in labeled IP1 as compared with controls. This result suggests that a substantial proportion of the signals transduced were due to activation of the muscarinic cholinergic receptor. Administration of ethanol (5 g/kg) to the atropine-treated mice resulted in a further decrease in labeled IP1 and longer sleep time as compared with those given ethanol alone.(ABSTRACT TRUNCATED AT 250 WORDS)
 
Article
The low level of response (LR) to alcohol is one of several genetically influenced characteristics that increase the risk for heavy drinking and alcohol problems. Efforts to understand how LR operates through additional life influences have been carried out primarily in modest-sized U.S.-based samples with limited statistical power, raising questions about generalizability and about the importance of components with smaller effects. This study evaluates a full LR-based model of risk in a large sample of adolescents from the United Kingdom. Cross-sectional structural equation models were used for the approximate first half of the age 17 subjects assessed by the Avon Longitudinal Study of Parents and Children, generating data on 1,905 adolescents (mean age 17.8 years, 44.2% boys). LR was measured with the Self-Rating of the Effects of Alcohol Questionnaire, outcomes were based on drinking quantities and problems, and standardized questionnaires were used to evaluate peer substance use, alcohol expectancies, and using alcohol to cope with stress. In this young and large U.K. sample, a low LR related to more adverse alcohol outcomes both directly and through partial mediation by all 3 additional key variables (peer substance use, expectancies, and coping). The models were similar in boys and girls. These results confirm key elements of the hypothesized LR-based model in a large U.K. sample, supporting some generalizability beyond U.S. groups. They also indicate that with enough statistical power, multiple elements contribute to how LR relates to alcohol outcomes and reinforce the applicability of the model to both genders.
 
Article
The subtypes of gamma-aminobutyric acid (GABA)(A) receptors mediating the discriminative stimulus effects of ethanol in nonhuman primates are not completely identified. The GABA(A) receptor positive modulator zolpidem has high, intermediate, and low activity at receptors containing alpha(1), alpha(2/3), and alpha(5) subunits, respectively, and partially generalizes from ethanol in several species. The partial inverse agonist Ro15-4513 has the greatest affinity for alpha(4/6)-containing receptors, higher affinity for alpha(5)- and lower, but equal, affinity for alpha(1)- and alpha(2/3)-, containing GABA(A) receptors, and antagonizes the discriminative stimulus effects of ethanol. This study assessed Ro15-4513 antagonism of the generalization of zolpidem from ethanol in male (n = 9) and female (n = 8) cynomolgus monkeys (Macaca fascicularis) trained to discriminate 1.0 g/kg (n = 10) or 2.0 g/kg (n = 7) ethanol (i.g.) from water with a 30-minute pretreatment interval. Zolpidem (0.017 to 5.6 mg/kg, i.m.) completely generalized from ethanol (>or=80% of total session responses on the ethanol-appropriate lever) for 6/7 monkeys trained to discriminate 2.0 g/kg and 4/10 monkeys trained to discriminate 1.0 g/kg ethanol. Zolpidem partially generalized from 1.0 or 2.0 g/kg ethanol in 6/7 remaining monkeys. Ro15-4513 (0.003 to 0.30 mg/kg, i.m., 5-minute pretreatment) shifted the zolpidem dose-response curve to the right in all monkeys showing generalization. Analysis of apparent pK(B) from antagonism tests suggested that the discriminative stimulus effects of ethanol common with zolpidem are mediated by low-affinity Ro15-4513 binding sites. Main effects of sex and training dose indicated greater potency of Ro15-4513 in males and in monkeys trained to discriminate 1.0 g/kg ethanol. Ethanol and zolpidem share similar discriminative stimulus effects most likely through GABA(A) receptors that contain alpha(1) subunits, however, antagonism by Ro15-4513 of zolpidem generalization from the lower training dose of ethanol (1.0 g/kg) may involve additional zolpidem-sensitive GABA(A) receptor subtypes (e.g., alpha(2/3) and alpha(5)).
 
Article
A preliminary investigation of immune host response was conducted in a group of fetal alcohol-exposed nonhuman primates (Macaca nemestrina) who were part of a broader ongoing study of ethanol teratogenicity. The mothers of the offspring received weekly oral doses of ethanol (1.8 g/kg) for the first 3 or 6 or the entire 24 weeks of gestation. A control group received sucrose solution weekly throughout pregnancy. Four of the 18 ethanol-exposed animals (22%) died or were euthanized after infectious disease or failure to thrive during the first year of life; none of the seven control animals died. This imbalance in survival prompted the present review of immune function in the remaining offspring. Parameters assessed included: (1) white blood cell count (WBC), (2) peripheral blood leucocyte subsets (CD4+, CD8+, CD20+, and CD11c+), (3) T-cell proliferation after activation with phytohemagglutinin (PHA), staphylococcus enterotoxin B (SEB), and tetanus toxoid (TT), (4) phagocytic activity of monocytes, and (5) serum immunoglobulin levels and serum antibody titers after TT vaccination. Mean T-cell proliferation to TT was significantly decreased (p = 0.01) in all ethanol-exposed animals relative to controls, with near-significant decreases (p = 0.06) in response to SEB in the ethanol-exposed animals. Lymphocyte proliferation in response to PHA was not altered. Ethanol-exposed animals had significantly lower TT titers than controls after initial vaccination and booster. WBC, leukocyte subsets, serum immunoglobulins, and monocyte phagocytic activity were not significantly different from control values. These preliminary observations suggest that T-cell proliferation and antigen-specific memory responses may be altered in offspring exposed to weekly doses of ethanol in utero and warrant further evaluation for confirmation.
 
Article
We found previously that alcohol-preferring (P) rats have fewer serotonin (5-HT) neurons and fibers in key brain regions than alcohol-nonpreferring (NP) rats. Because 5-HT uptake blockers increase synaptic 5-HT content and 5-HT1A receptor antagonists increase 5-HT release by disinhibiting 5-HT autoinnervation, in the present study, our intent was to determine whether increased synaptic 5-HT content and/or 5-HT release in P rats would effectively reduce alcohol consumption. In experiment 1, the 5-HT antagonist WAY 100635 (WAY) was tested on adult female P rats maintained on 24-hr free-choice access to ethanol (10% v/v) and water. Twice daily doses of WAY (0.05, 0.1, 0.5, and 1.0 mg/kg, subcutaneously) were administered to each rat in a counterbalanced order. Baseline ethanol intake, derived from the mean ethanol intakes of the three previous non-drug days, was approximately 8 g/kg/day. Results indicated that 0.05, 0.1, and 0.5 mg/kg doses of WAY reduced 24-hr ethanol drinking by 25-30% (p < 0.01) without affecting 24-hr water intake or body weight. In the second experiment, the effects of WAY (0.5 mg/kg), fluoxetine (1.0 mg/kg), or a combination of both were tested in another group of female P rats. WAY and fluoxetine, each alone, reduced ethanol drinking by around 20% and, when combined, decreased ethanol intake by 50%, whereas the body weight and the total fluid intake were not significantly affected. Taken together, these results indicate that both fluoxetine and WAY preferentially reduce ethanol drinking in the P line of rats and, when administered together, reduce ethanol intake in an additive manner. It is proposed that coadministration of these two compounds with distinct mechanisms of action may be a new strategy for reducing alcohol intake.
 
Article
Prior research indicates risk for alcoholism is increased among individuals who begin to drink at an early age. We replicate and extend these findings, addressing causal and noncausal explanations for this association. Structured psychiatric interviews, including assessment of lifetime DSM-IV alcohol abuse and alcohol dependence (AD), were conducted with 8746 adult twins ascertained through a population-based twin registry. We found strong evidence for an association between early drinking onset and risk for AD, but less evidence for an association with alcohol abuse. The results of twin-pair analyses suggest that all of the association between early drinking and later AD is due to familial sources, which probably reflect both shared environmental and genetic factors. These results suggest the association between drinking onset and diagnosis is noncausal, and attempts to prevent the development of AD by delaying drinking onset are unlikely to be successful.
 
The Effect of DOV 102,677 on the Volitional Consumption of Ethanol by Male mHEP Rat
The Effect of DOV 102,677 on Food Consumption and Body Weight of Male mHEP Rat
Article
Background: Inhibitors of monoamine neurotransmitter transporters are well established as antidepressants. However, the evidence that single (serotonin) or dual (serotonin-norepinephrine) neurotransmitter uptake inhibitors can treat ethanol abuse, either as a comorbidity with depression or as a separate entity, is inconsistent. Drugs that have, in addition, the ability to inhibit dopamine uptake may have an advantage in the treatment of alcohol abuse. Therefore, the inhibitor of norepinephrine, serotonin and dopamine uptake, DOV 102,677, was tested for its effects on the volitional consumption of ethanol by an ethanol-preferring rat strain. Methods: Myers' high ethanol-preferring rats were screened by a 10-day, 3 to 30% step-up test and then given free access to the preferred concentration of ethanol in a 3-bottle choice task. Consumption of ethanol (g/kg), water, food, and body weight were measured daily during a 3-day predrug treatment period, a 3-day treatment period, and a 3-day posttreatment period. Additional Sprague-Dawley rats were observed for 24 hours for the behavioral effects of 2.0 mg/kg s.c. reserpine after a 30-minute pretreatment with different doses of DOV 102,677. Results: The triple monoamine uptake inhibitor DOV 102,677 dose-dependently decreased the volitional consumption of ethanol by as much as 71.2% (20 mg/kg i.p., b.i.d.) over 3 days of administration. This effect carried over into the posttreatment period. Similarly, the proportion of ethanol to total fluids consumed declined by 66.2% (20 mg/kg s.c., b.i.d.), while food consumption and body weight were unaltered. In contrast, amperozide (2 mg/kg i.p., b.i.d.) suppressed the amount of ethanol consumed by 56%, while naltrexone (5 mg/kg i.p., b.i.d.) was without effect. DOV 102,677 (40 mg/kg s.c.) inhibited reserpine-induced akinesia and ptosis, but not hypothermia in Sprague-Dawley rats, consistent with its transient inhibition of serotonin transport, and more long-lived inhibition of norepinephrine and dopamine uptake. Conclusions: DOV 102,677 significantly decreased the volitional consumption of ethanol with minimal alterations in the intake of food or on body weight in an ethanol-preferring rat strain, suggesting that triple reuptake inhibitors may find utility in treating alcohol abuse.
 
Article
  Concurrent inhibitors of dopamine, norepinephrine, and serotonin uptake have been proposed as novel antidepressants. Given the high comorbidity between alcoholism and depression, we evaluated the activity of DOV 102,677 (DOV) on alcohol-maintained responding and performance in the forced swim test (FST), a model of antidepressant (AD) activity, using alcohol-preferring (P) rats.   Following training to lever press for either alcohol (10% v/v) or sucrose (3, 2%, w/v) on a fixed-ratio 4 (FR4) schedule, DOV (1.56 to 50 mg/kg; PO) was given 25 minutes or 24 hours prior to evaluation. The effects of DOV (12.5 to 50 mg/kg; PO) in the FST were evaluated 25 minutes posttreatment.   DOV (6.25 to 50 mg/kg) dose-dependently reduced alcohol-maintained responding by 59 to 88% at 25 minutes posttreatment, without significantly altering sucrose responding. The reduction in alcohol responding (44% at 50 mg/kg) was sustained for up to 120 hours after a single dose. Administration of a single dose of DOV (25, 50 mg/kg) 24 hours before testing suppressed alcohol responding for 48 hours by 59 to 62%. DOV (12.5 to 50 mg/kg) also dose-dependently reduced immobility of P rats in the FST.   DOV produces both prolonged and selective reductions of alcohol-motivated behaviors in P rats. The elimination kinetics of DOV suggests that its long duration of action may be due to an active metabolite. DOV also produced robust AD-like effects in P rats. We propose that DOV may be useful in treating comorbid alcoholism and depression in humans.
 
Article
A review of the many attempts to establish an association between occupations and alcoholism reveals that most do not deal with data about clinically defined alcoholism but instead use data about cirrhosis mortality, self-reported alcohol problems, and frequent and heavy drinking. The present study establishes an association between occupations and diagnoses of Alcohol Dependence Disorder and Alcohol Abuse Disorder, using data from a large population-based household interview study. Statistical adjustment using logistic methods reveals that apparent associations between occupations and alcohol-related disorders previously reported in the literature are due to characteristics of those employed in various occupations. The prevalence of alcohol dependence and abuse in two high risk industries, construction and transportation, is confirmed. More than one in four construction laborers and one in five skilled construction trades workers received a DIS/DSM-III diagnosis related to alcohol abuse. In the transportation industry one in six heavy truck drivers and material movers received an alcohol diagnosis. Analyses of the data from individuals currently employed and not employed in their occupation reveals reduction in risk for those who leave some occupations and increased risk for those who leave other occupations. Evidence is presented that employment in some occupations may be protective for Alcohol Dependence. The findings support the view that occupation may be associated with Alcohol Dependence and Alcohol Abuse independent of demographic variations. Previously proposed explanatory models for associations between occupations and alcohol problems are called into question because they do not take into account the demographic characteristics and employment status of workers.
 
Article
Background: Alcohol (EtOH [ethanol]) is an antinociceptive agent, working in part, by reducing sensitivity to painful stimuli. The transcription factor Kruppel-like factor 11 (KLF11), a human diabetes-causing gene that also regulates the neurotransmitter metabolic enzymes monoamine oxidase (MAO), has recently been identified as an EtOH-inducible gene. However, its role in antinociception remains unknown. Consequently, we investigated the function of KLF11 in chronic EtOH-induced antinociception using a genetically engineered knockout mouse model. Methods: Wild-type (Klf11(+/+) ) and KLF11 knockout (Klf11(-/-) ) mice were fed a liquid diet containing EtOH for 28 days with increasing amounts of EtOH from 0% up to a final concentration of 6.4%, representing a final diet containing 36% of calories primarily from EtOH. Control mice from both genotypes were fed liquid diet without EtOH for 28 days. The EtOH-induced antinociceptive effect was determined using the tail-flick test before and after EtOH exposure (on day 29). In addition, the enzyme activity and mRNA levels of MAO A and MAO B were measured by real-time RT-PCR and enzyme assays, respectively. Results: EtOH produced an antinociceptive response to thermal pain in Klf11(+/+) mice, as expected. In contrast, deletion of KLF11 in the Klf11(-/-) mice abolished the EtOH-induced antinociceptive effect. The mRNA and protein levels of KLF11 were significantly increased in the brain prefrontal cortex of Klf11(+/+) mice exposed to EtOH compared with control Klf11(+/+) mice. Furthermore, MAO enzyme activities were affected differently in Klf11 wild-type versus Klf11 knockout mice exposed to chronic EtOH. Chronic EtOH intake significantly increased MAO B activity in Klf11(+/+) mice. Conclusions: The data show KLF11 modulation of EtOH-induced antinociception. The KLF11-targeted MAO B enzyme may contribute more significantly to EtOH-induced antinociception. Thus, this study revealed a new role for the KLF11 gene in the mechanisms underlying the antinociceptive effects of chronic EtOH exposure.
 
Article
Expression of the class I alcohol dehydrogenase (ADH) gene in the rat hepatoma microcell hybrid cell line, 11-3, was examined. The steady-state level of ADH mRNA in 11-3 was approximately 2-fold higher than that or rat liver and Fao, the parental cell line of 11-3. Removal of steroid hormones by activated charcoal from the serum in which 11-3 cells were maintained resulted in a significant decrease in the level of ADH transcript. Dexamethasone at a concentration of 1 muM increased the ADH mRNA content in 11-3 in a time-dependent fashion, up to 48 hr after its addition to cells that had first been deprived of steroid hormones. In addition, levels of ADH transcript in cells treated with dexamethasone increased in a dose-dependent manner, and the concentration of dexamethasone required to achieve half-maximal activation was 5 nM. By using the techniques of reverse transcription and polymerase chain reaction, and by taking advantage of a restriction polymorphism present between the rat and mouse ADH cDNA, we found that 11-3 contained both the rat and mouse class I ADH transcripts, although the rat sequence accounted for the great majority. Moreover, levels of both rat and mouse class I ADH transcripts increased in a similarly time-dependent manner in cells treated with dexamethasone. These results indicate that expression of class I ADH gene in 11-3 is high and is regulated by glucocorticoids, making the cell line an excellent model for the in vitro study of ADH expression.
 
Article
Binge, as well as chronic, alcohol consumption affects global histone acetylation leading to changes in gene expression. It is becoming increasingly evident that these histone-associated epigenetic modifications play an important role in the development of alcohol-mediated hepatic injury. C57BL/6 mice were gavaged 3 times (12-hour intervals) with ethanol (EtOH; 4.5 g/kg). Hepatic histone deacetylase (Hdac) mRNAs were assessed by qRT-PCR. Total HDAC activity was estimated by a colorimetric HDAC activity/inhibition assay. Histone acetylation levels were evaluated by Western blot. Liver steatosis and injury were evaluated by histopathology, plasma aminotransferase (ALT) activity, and liver triglyceride accumulation. Expression of fatty acid synthase (Fas) and carnitine palmitoyl transferase 1a (Cpt1a) was also examined. HDAC 9 association with Fas promoter was analyzed. Binge alcohol exposure resulted in alterations of hepatic Hdac mRNA levels. Down-regulation of HDAC Class I (Hdac 1), Class II (Hdac 7, 9, 10), and Class IV (Hdac 11) and up-regulation of HDAC Class I (Hdac 3) gene expression were observed. Correspondent to the decrease in HDAC activity, an increase in hepatic histone acetylation was observed. These molecular events were associated with microvesicular hepatic steatosis and injury characterized by increased hepatic triglycerides (48.02 ± 3.83 vs. 19.90 ± 3.48 mg/g liver, p < 0.05) and elevated plasma ALT activity (51.98 ± 6.91 vs. 20.8 ± 0.62 U/l, p < 0.05). Hepatic steatosis was associated with an increase in FAS and a decrease in CPT1a mRNA and protein expression. Fas promoter analysis revealed that binge EtOH treatment decreased HDAC 9 occupancy at the Fas promoter resulting in its transcriptional activation. Deregulation of hepatic Hdac expression likely plays a major role in the binge alcohol-induced hepatic steatosis and liver injury by affecting lipogenesis and fatty acid β-oxidation.
 
Article
Alcohol dependence is a complex disease, and although linkage and candidate gene studies have identified several genes associated with the risk for alcoholism, these explain only a portion of the risk. We carried out a genome-wide association study (GWAS) on a case-control sample drawn from the families in the Collaborative Study on the Genetics of Alcoholism. The cases all met diagnostic criteria for alcohol dependence according to the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition; controls all consumed alcohol but were not dependent on alcohol or illicit drugs. To prioritize among the strongest candidates, we genotyped most of the top 199 single nucleotide polymorphisms (SNPs) (p < or = 2.1 x 10(-4)) in a sample of alcohol-dependent families and performed pedigree-based association analysis. We also examined whether the genes harboring the top SNPs were expressed in human brain or were differentially expressed in the presence of ethanol in lymphoblastoid cells. Although no single SNP met genome-wide criteria for significance, there were several clusters of SNPs that provided mutual support. Combining evidence from the case-control study, the follow-up in families, and gene expression provided strongest support for the association of a cluster of genes on chromosome 11 (SLC22A18, PHLDA2, NAP1L4, SNORA54, CARS, and OSBPL5) with alcohol dependence. Several SNPs nominated as candidates in earlier GWAS studies replicated in ours, including CPE, DNASE2B, SLC10A2, ARL6IP5, ID4, GATA4, SYNE1, and ADCY3. We have identified several promising associations that warrant further examination in independent samples.
 
Article
Magnetic resonance imaging was used to quantify the volume of the hippocampus in 47 men with chronic alcoholism and 72 healthy male control subjects. The subjects ranged in age from 21 to 70 years, thus permitting a test of whether older alcoholics suffer greater brain tissue volume reduction than do younger ones. Comparison brain regions included temporal lobe gray matter, white matter, and cerebrospinal fluid, as well as measures of the lateral ventricles, third ventricle, and temporal horns. The results of this cross-sectional study showed that the anterior, but not the posterior, portions of the hippocampus in both hemispheres were significantly smaller in the alcoholic than the healthy control group. Furthermore, the bilateral anterior hippocampal volume loss was greater in older than younger alcoholics. Despite the hippocampal volume deficit, these alcoholics did not demonstrate an explicit memory impairment; furthermore, memory test scores did not correlate significantly with hippocampal volumes. In the alcoholics, the age-related volume loss, which was over and above that expected in normal aging, was also evident in the temporal cortex and white matter. Likewise, alcoholic ventricular enlargement was age-related. Analysis of covariance revealed that the anterior hippocampal deficit persisted after accounting for the temporal lobe gray matter volume deficit. Multiple regression analysis revealed that the age-related brain volume abnormalities observed in the alcoholics could not be attributed to duration of alcoholism or total lifetime consumption of alcohol.
 
Article
Acute and chronic ethanol exposure produces profound impairments in motor functioning. Individuals with lower sensitivity to the acute motor impairing effects of ethanol have an increased risk of developing alcohol dependence and abuse, and infants with subtle delays in motor coordination development may have an increased risk for subsequently developing alcoholism. Thus, understanding the mechanism by which ethanol disrupts motor functioning is very important. Parasagittal slices of the cerebellar vermis (250 microM thick) were prepared from P17 to 20 Sprague-Dawley rats. Whole-cell recordings of Purkinje cells were obtained with an Axopatch 200B amplifier. Parallel fiber-Purkinje cell synaptic currents were sampled at 1 kHz and digitized at 10 kHz, and synaptic long-term depression (LTD) was observed in either external or internal application of ethanol for comparison. We determined whether ethanol acutely affects parallel fiber LTD using whole-cell patch-clamp recordings from Purkinje cells. Application of ethanol both externally (50 mM) and internally (17 and 10 mM) significantly suppressed mGluR-mediate slow currents. Short-term external ethanol exposure (50 but not 17 mM) during tetanus blocked mGluR-dependent parallel fiber LTD. Furthermore, internal 17 and 10 mM ethanol completely inhibited this LTD. The results of the current study demonstrate that ethanol acutely suppresses parallel fiber LTD and may influence the mGluR-mediated slow current intracellularly. This study, plus previous evidence by Carta and colleagues (2006) and Belmeguenai and colleagues (2008), suggests significant actions of ethanol on mGluR-mediated currents and its dependent plasticity in brain.
 
Article
As only a minority of alcoholics develop cirrhosis, polymorphic genes, whose products are involved in fibrosis development were suggested to confer individual susceptibility. We tested whether a functional promoter polymorphism in the gene encoding matrix metalloproteinase-3 (MMP-3; 1171 5A/6A) was associated liver cirrhosis in alcoholics. Independent cohorts from the UK and Germany were studied. (i) UK cohort: 320 alcoholic cirrhotics and 183 heavy drinkers without liver damage and (ii) German cohort: 149 alcoholic cirrhotics, 220 alcoholic cirrhotics who underwent liver transplantation and 151 alcoholics without liver disease. Patients were genotyped for MMP-3 variants by restriction fragment length polymorphism, single strand confirmation polymorphism, and direct sequencing. In addition, MMP-3 transcript levels were correlated with MMP-3 genotype in normal liver tissues. Matrix metalloproteinase-3 genotype and allele distribution in all 1023 alcoholic patients were in Hardy-Weinberg equilibrium. No significant differences in MMP-3 genotype and allele frequencies were observed either between alcoholics with or without cirrhosis. There were no differences in hepatic mRNA transcription levels according to MMP-3 genotype. Matrix metalloproteinase-3 1171 promoter polymorphism plays no role in the genetic predisposition for liver cirrhosis in alcoholics. Stringently designed candidate gene association studies are required to exclude chance observations.
 
Sample Characteristics of Alcohol-Dependent Individuals Across Recruitment Centers and Controls
Association Between Alcoholism-Related Phenotypes and OPRM Alleles and Genotypes (rs1799971 A118G)
Article
Several lines of evidence from previous research indicate that opioid receptors play an important role in ethanol reinforcement and alcohol dependence (AD) risk. Conflicting results were reported on the role of the mu-opioid receptor (OPRM1) polymorphism A118G (Asn40Asp, rs1799971) in the development of alcoholism. We investigated a total number of 1,845 alcohol-dependent subjects recruited from inpatient facilities in Germany and 1,863 controls for the mu-opioid receptor (OPRM1) polymorphism using chi-square statistics. An association between the OPRM variant and AD was detected (p = 0.022), in recessive (AA vs. GA/GG) and co-dominant (AA vs. GA) models of inheritance. An association between the OPRM variant and the DSM-IV criterion "efforts to cut down or could not" (p = 0.047) was found, but this did not remain significant after the correction for multiple testing. The results indicate that this functional OPRM variant is associated with risk of AD and these findings apply to more severe AD, although the association is only nominally significant.
 
Article
In both animal and human studies, ethanol seems to modulate host immune function. In a variety of animal studies, ethanol has been shown to decrease lymphocyte function and number. In human studies of patients with alcoholic hepatitis, these abnormalities were also seen with specific correlation with protein malnutrition. Hepatic pathological lesions were also correlated with lymphocyte subset infiltration. However, peripheral blood lymphocytes did not correlate consistently with hepatic histopathology.
 
Article
Alcoholism and aggression have each been associated with neurochemical measurements suggestive of decreased serotonin synaptic transmission. We measured densities of the serotonin transporter (SERT) in a moderate-sized sample of alcoholic patients who were assessed for aggressive characteristics. Thirty alcoholic inpatients and 18 healthy controls received a PET scan with [(11)C]-3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile. The alcoholic inpatients were classified as aggressive or nonaggressive based on a comparison between the top third and bottom third scores on the Buss-Durkee Hostility Index. Using a pixel-wise comparison, no brain region showed significant alterations in SERT binding among the 3 groups of subjects (aggressive alcoholic subjects, nonaggressive alcoholic subjects, and healthy controls) or between the combined alcoholic group and healthy controls. None of the clinical measures (including measures of aggression) correlated with SERT binding in the alcoholic subjects. Contrary to prior imaging reports using the nonselective ligand [(123)I]beta-CIT, we found no significant alterations of SERT density in alcoholic patients.
 
Article
One hundred twenty women alcoholics recruited to a treatment program called EWA (Early Treatment for Women With Alcohol Addiction) were studied. The selected women were not previously treated for alcohol abuse. The women were followed up by use of a structured personal interview, biomarkers sensitive for alcohol abuse (i.e., glutamyl transpeptidase), and questionnaires, by using defined criteria for abstinence, social drinking, satisfactory drinking outcome, and unsatisfactory drinking outcome. Drinking outcome was good (i.e., total abstinence, social drinking, or satisfactory drinking outcome) for 67% of the women during the total follow-up time, by use of strict criteria for relapse. The results were corroborated by the biomarkers. Similar results were reported from two previously studied groups of women from the same department. However, the frequency of abstinence was higher and social drinking was significantly lower among this sample of women. Daily drinking, the use of sedatives, and a long duration of pretreatment alcohol abuse predicted an unfavorable outcome. However, a long duration of outpatient treatment predicted a good outcome, whereas treatment dropout was related to an unsatisfactory drinking outcome. A majority of the women (96%) rated the treatment experience and the treatment program favorably. The overall good results might reflect the selection of the subjects studied. Improving treatment program adherence would probably improve outcome for the women with an unsatisfactory drinking outcome.
 
Article
This work tests the hypothesis that chronic alcohol intoxication suppresses the microbicidal activity of Kupffer cells by modulating the expression of cell surface receptors associated with respiratory burst and the release of potent microbicidal agents [i.e., reactive oxygen species (ROS)]. Because alcohol is also a potential risk factor in human immunodeficiency virus-1 (HIV-1) infection, this study examines the effect of HIV-1 glycoprotein 120 (gp120)-induced ROS release by isolated Kupffer cells. After 16 weeks of ethanol feeding, Kupffer cells from male Sprague-Dawley rats were isolated and assayed for HIV-1 gp120-induced superoxide release. Fluorescein isothiocyanate (FITC)-HIV-1 gp120 binding, NADPH oxidase, and protein kinase C activity in Kupffer cells were measured. Results show that HIV-1 gp120 induced the release of superoxide anion in a dose-dependent manner in normal rats. Mannosylated-bovine serum albumin inhibited FITC-HIV-1 gp120-mediated superoxide release in normal Kupffer cells by 85%. Moreover, 83 +/- 6% of Kupffer cells were FITC-HIV 1 gp120-positive, whereas <30% were CD4-positive. In alcohol-fed rats, HIV-1 gp120-induced ROS release was reduced by 70% and FITC-HIV-1 gp120 binding (in terms of fluorescence intensity per 10[6] Kupffer cells) by 44% in Kupffer cells, without any change in percent positive cells for this ligand. Concomitantly, HIV-1 gp120-induced translocation of NADPH oxidase to the plasma membranes of Kupffer cells in alcohol-fed rats was suppressed by 60%. In contrast, alcohol consumption significantly increased total protein kinase C activity and phorbol ester-induced superoxide release by Kupffer cells. These studies demonstrate that Kupffer cells are likely targets of HIV-1 whose binding sites on macrophages could also include mannose-specific receptors. These observations further suggest that suppression of HIV-1 gp120-mediated ROS production in chronic alcoholics is due to altered cell surface receptor expression for gp120, and defective postreceptor signaling mechanisms, which in turn could lead to attenuated microbicidal activity of hepatic macrophages.
 
Article
Alcohol dependence has repeatedly been associated with impulsive choice, or the inability to choose large delayed rewards over smaller, but more immediate rewards. However, the neural basis of impulsive choice in alcohol use disorders (AUDs) is not well understood. One hundred fifty-one individuals with a range of alcohol use from social drinking to severe alcohol dependence completed a delay discounting task while undergoing functional magnetic resonance imaging. Participants received customized trials designed to ensure an approximately equivalent number of immediate responses. Delaying gratification recruited regions involved in cognitive control, conflict monitoring, and the interpretation of somatic states. Individuals with more severe alcohol use problems showed increased discounting of delayed rewards and greater activation in several regions including supplementary motor area, insula/orbitofrontal cortex, inferior frontal gyrus, and the precuneus. These results suggest that impulsive choice in alcohol dependence is the result of functional anomalies in widely distributed, but interconnected brain regions involved in cognitive and emotional control. Furthermore, our results suggest that the neural mechanisms of impulsive choice in AUD both overlaps with that observed in previous studies, and shows that individuals with AUD recruit additional mechanisms when making intertemporal choices.
 
Article
Clinical studies demonstrate synergistic liver damage by alcohol and hepatitis C virus (HCV); however, the mechanisms by which alcohol promotes HCV infection remain obscure. The liver-specific microRNA-122 (miR-122) regulates HCV replication and expression of host genes, including Cyclin G1. Here, we hypothesized that alcohol regulates miR-122 expression and thereby modulates HCV RNA replication. The J6/JFH/Huh-7.5 model of HCV infection was used in this study. Real-time quantitative polymerase chain reaction, Western blotting, electrophoretic mobility shift assay, and confocal microscopy were used for experimental analysis. We found that acute alcohol exposure (25 mM) significantly increased intracellular HCV RNA as well as miR-122 levels in Huh-7.5 and Huh-7.5/CYP2E1 expressing cells in the presence and absence of J6/JFH-HCV infection. Expression of the miR-122 target, Cyclin G1, was inhibited by alcohol both in J6/JFH-infected and uninfected Huh-7.5 cells. The use of a miR-122 inhibitor increased Cyclin G1 expression and prevented the alcohol-induced increase in HCV RNA and protein levels, suggesting a mechanistic role for alcohol-induced miR122 in HCV replication. We discovered that siRNA-mediated silencing of Cyclin G1 significantly increased intracellular HCV RNA levels compared with controls, suggesting a mechanistic role for Cyclin G1 in HCV replication. Alcohol-induced increase in miR-122 was associated with increased nuclear translocation and DNA binding of the nuclear regulatory factor-κB and could be prevented by NF-κB inhibition. Our novel data indicate a miR-122-mediated mechanism for alcohol increasing HCV RNA replication. We show for the first time that Cyclin G1, a miR-122 target gene, has regulatory effects on HCV replication and that alcohol increases HCV replication by regulating miR-122 and Cyclin G1.
 
Article
Background: Although alcohol dependence in women is an increasing problem, little is known about the effects of alcohol on the female brain. Evidence from a few structural and functional neuroimaging studies suggests that the female brain may be more susceptible than the male brain to the harmful effects of alcohol. However, no in vivo studies of the neuropharmacology of alcohol dependence in women have been carried out. The aim of this preliminary study was to test the hypothesis that alcohol dependence in women is associated with greater reduction in γ-aminobutyric acid (GABA)-benzodiazepine receptor levels than in men with an equivalent drinking history. Methods: We used single photon emission tomography and 123I-iomazenil to label the central GABA-benzodiazepine receptor and to compare semiquantified levels in 9 abstinent alcohol-dependent and 13 control women. These groups were further compared with equivalent male groups from a previous study. Results: There was a trend toward a reduction in GABA-benzodiazepine receptor levels in alcohol-dependent women, but this did not reach significance. These lower levels were seen primarily in the cerebellum, occipital lobes, and parietal cortex (left > right). This was in marked contrast with the pattern of reduction seen in the previous study of male dependence, where significant reductions were seen primarily in the frontal cortex. Conclusions: Due to the semiquantitative analysis performed and the relatively small number of subjects in this study, which resulted in a nonsignificant trend, we can only comment on the differences in the pattern of lower levels of GABA-benzodiazepine receptors seen in alcohol dependence in men and women. Although we are not able to ascertain whether the female brain is more susceptible to the effects of alcohol, it appears that alcohol has a differential effect on the central GABA-benzodiazepine receptors in men and women. Recent animal evidence supports this hypothesis. Future studies should explore whether other neuropharmacological differences exist between men and women in alcohol dependence that could have implications for pharmacotherapy.
 
Article
Brain gamma-aminobutyric acid (GABA) systems have long been associated with the behavioral actions of ethanol. This study investigated the effects of GABAergic agents on ethanol reinforcement. Rats were trained to orally self-administer ethanol in a 30-min, free-choice operant task. Responses at one of two levers produced contingent access to ethanol (10% w/v) or water. Pretreatment with RO 15-4513, a benzodiazepine inverse agonist (0.375 to 3.0 mg/kg ip), selectively reduced responses for ethanol, and a higher dose of RO 15-4513 (6.0 mg/kg) reduced both ethanol and water responses. Self-administration of saccharin in a free-choice task with access to saccharin (0.05%) and water was unaffected by RO 15-4513, suggesting that the effects of RO 15-4513 on ethanol reinforcement may not necessarily generalize to other reinforcers. Isopropylbicyclophosphate (IPPO), a picrotoxin ligand (5 and 10 micrograms/kg ip), selectively reduced responses for ethanol in alcohol-preferring, nonpreferring and Wistar rats. However, the highest dose of IPPO (20 micrograms/kg) reduced both ethanol and water responses. Chlordiazepoxide, a benzodiazepine, did not reduce responses for ethanol in the selectively bred animals, suggesting that this drug does not substitute for the reinforcing properties associated with acute ethanol intake. Together, these results suggest that compounds that act at the benzodiazepine inverse agonist and picrotoxin sites of the GABA/benzodiazepine receptor complex may decrease motivated responding for ethanol.
 
Article
This study was designed to examine the effects of acute intraperitoneal (i.p.) ethanol injection on the extracellular levels of serotonin (5-HT) in the ventral hippocampus (vHIP) and to determine whether a single prior exposure to ethanol could alter the response to a second dose of ethanol given 24 hr later. In the first experiment, in vivo microdialysis coupled with high pressure liquid chromatography-electrochemical detection (HPLC-EC) was used to assess the effects of 1.0, 1.75, and 2.5 g/kg ethanol on vHIP 5-HT extracellular levels in ethanol-naïve adult male Wistar rats. The largest dose significantly increased the extracellular concentration of 5-HT (p < 0.001) to a maximum of approximately 180% of baseline values within 50 min; thereafter, the levels of 5-HT began to return toward baseline. The 1.75 g/kg dose also transiently increased 5-HT levels above baseline; however, no significant increase was observed with 1.0 g/kg ethanol. The results of the second experiment demonstrated that the i.p. dose of 2.5 g/kg ethanol had no significant effect on the extracellular levels of 5-HT if rats had been given a single i.p. 2.5 g/kg dose of ethanol 24 hr earlier. Because the vHIP receives a major 5HT input from the median raphe nucleus (MRN), the results suggest that acute ethanol activates the MRN 5-HT system projecting to the vHIP and that rapid tolerance develops to the activating effects of alcohol on this pathway.
 
Article
We have been using a genetic strategy to define the contribution of specific candidate genes, such as those encoding subunits of the gamma-aminobutyric acid type A receptor, to various ethanol sensitive responses. We have used the gene knockout approach in mouse embryonic stem cells to create mice in which the gene encoding the alpha6 subunit of the gamma-aminobutyric acid type A receptor is rendered nonfunctional. In the present report, we provide a detailed characterization of several behavioral responses to ethanol in these null allele mice. In a separate series of experiments, behavioral response to ethanol was compared between two inbred strains of mice that are commonly used as background stock in knockout experiments, namely C57BL/6J and Strain 129/SvJ. Wild type (alpha6+/+) and homozygous null allele (alpha6-/-) mice did not differ to the ataxic effects of ethanol on acute functional tolerance (95.8 +/- 8.7 vs. 98.8 +/- 5.7 mg/dl +/- SEM, respectively). Withdrawal hyperexcitability was assessed following chronic exposure to ethanol vapor (EtOH) or air (CONT) in inhalation chambers in a multiple withdrawal treatment paradigm. At the end of the last treatment cycle, mice were scored for handling induced convulsions (HIC). After adjusting for differences in blood ethanol concentration between genotypes at the end of the final treatment cycle, we observed a greater area under the 24-hr HIC curves in mice treated with ethanol (p < 0.0001) but did not detect an effect of genotype (alpha6+/+/CONT 3.1 +/- 2.0; alpha6-/-/CONT 5.5 +/- 2.5; alpha6+/+/EtOH 30.1 +/- 6.2; alpha6-/-/EtOH 33.0 +/- 5.8 mean units +/- SEM). We also examined these mice for differences in protracted tolerance; at approximately 26 hr into the final withdrawal cycle, each mouse was injected with ethanol (3.5 mg/g body weight) and sleep time was measured. We detected a significant effect of treatment (p < 0.001) with ethanol-treated mice demonstrating signs of tolerance as reflected by a reduction in duration of sleep time. However, effect of genotype was not significant (alpha6+/+/CONT 57.4 +/- 7.6; alpha6-/-/CONT 59.0 +/- 7.6; alpha6+/ +/EtOH 34.8 +/- 7.4; alpha6-/-/EtOH 30.8 +/- 5.6 min +/- SEM). From these data we conclude that the alpha6 subunit of the GABA(A)-R exerts little if any influence on acute functional tolerance, withdrawal hyperexcitability, or protracted tolerance. Strain 129/SvJ and C57BL/6J mice were also compared for acute functional tolerance and were found not to differ (96.3 +/- 4.4 vs. 94.8 +/- 11.3 mg/dl +/- SEM, respectively). Withdrawal hyperexcitability was assessed by comparing the area under the 24 hr HIC curves. Strain 129/SvJ mice displayed a much greater basal HIC response compared to C57BL/6J mice (19.8 +/- 4.3 vs. 0.2 +/- 0.2 mean units +/- SEM, respectively); after adjusting for differences in blood ethanol concentration between strains at the end of the final ethanol treatment cycle, the HIC response was markedly enhanced by ethanol treatment in Strain 129/SvJ mice but not in C57BL/6J mice (50.4 +/- 3.1 vs. 9.5 +/- 5.4 mean units +/- SEM, respectively). The effects of treatment (p < 0.0001), strain (p < 0.0001), and the interaction of strain with treatment (p < 0.01) were significant. Since many gene knockout mice are maintained on a mixed genetic background of Strain 129/SvJ and C57BL/6J, we conclude that significant differences in tests of withdrawal hyperexcitability may be confounded by the influence of genes that cosegregate with the gene targeted allele.
 
Article
Mice of the C57BL/6ByJ (B6) and 129/J (129) strains were offered different concentrations of taste solutions in 48-hr, two-bottle choice tests. In comparison with the 129 strain, the B6 strain had higher preferences for ethanol, sucrose, and citric acid. They had lower preferences for NaCl and similar preferences for capsaicin and quinine hydrochloride. These data are consistent with the hypothesis that the higher ethanol intake by B6 mice depends, in part, on higher hedonic attractiveness of its sweet taste component.
 
Article
Background: The melanocortin (MC) system is composed of peptides that are cleaved from the polypeptide precursor, pro-opiomelanocortin (POMC). Previous research has shown that MC receptor (MCR) agonists reduce, and MCR antagonists increase, ethanol consumption in rats and mice. Consistently, genetic deletion of the endogenous MCR antagonist, agouti-related protein (AgRP), causes reductions of ethanol-reinforced lever pressing and binge-like ethanol drinking in C57BL/6J mice. Ethanol also has direct effects on the central MC system, as chronic exposure to an ethanol-containing diet causes significant reductions of alpha-melanocyte stimulating hormone (alpha-MSH) immunoreactivity in specific brain regions of Sprague-Dawley rats. Together, these observations suggest that the central MC system modulates neurobiological responses to ethanol. To further characterize the role of the MC system in responses to ethanol, here we compared AgRP and alpha-MSH immunoreactivity in response to an acute injection of saline or ethanol between high ethanol drinking C57BL/6J mice and moderate ethanol drinking 129/SvJ mice. Methods: Mice received an intraperitoneal (i.p.) injection of ethanol (1.5 g/kg or 3.5 g/kg; mixed in 0.9% saline) or an equivolume of 0.9% saline. Two hours after injection, animals were sacrificed and their brains were processed for AgRP and alpha-MSH immunoreactivity. Results: Results indicated that acute ethanol administration triggered a dose-dependent increase in AgRP immunoreactivity in the arcuate (ARC) of C57BL/6J mice, an effect that was not evident in the 129/SvJ strain. Although acute administration of ethanol did not influence alpha-MSH immunoreactivity, C57BL/6J mice had significantly greater overall alpha-MSH immunoreactivity in the ARC, dorsomedial, and lateral regions of the hypothalamus relative to the 129/SvJ strain. In contrast, C57BL/6J mice displayed significantly lower alpha-MSH immunoreactivity in the medial amygdala. Conclusions: The results show that acute ethanol exposure has direct effects on endogenous AgRP activity in ethanol preferring C57BL/6J mice. It is suggested that ethanol-induced increases in AgRP may be part of a positive feedback system that stimulates excessive binge-like ethanol drinking in C57BL/6J mice. Inherent differences in alpha-MSH immunoreactivity may contribute to differences in neurobiological responses to ethanol that are characteristically observed between the C57BL/6J and 129/SvJ inbred strains of mice.
 
Article
Three comparable representative samples of 7th to 12th grade students in New York State were surveyed in 1983, 1990, and 1994 to determine changes in the patterns of alcohol use over the past decade. Each of the three samples was large (n = 27,335, 23,860, and 19,321, respectively), permitting detailed analysis of changes in alcohol use in various adolescent subgroups according to age, gender, and race/ethnicity. Previous research revealed that there were marked decreases in the prevalence of overall drinking, heavy drinking, and alcohol-related problems from 1983 to 1990, yet recent national reports indicate that since 1990 there has been an upsurge in substance use among adolescents. Whereas the proportion of drinkers did not significantly increase between 1990 and 1994, average consumption, heavy drinking, and alcohol-related problems all showed modest, but significant increases in the 1990s. Furthermore, between 1990 and 1994, the age distributions for alcohol use, heavy drinking, and alcohol problems changed, as evidenced by significant age by year of survey interactions. These findings indicate that adolescents are currently drinking, drinking heavily, and experiencing alcohol-related problems at younger ages that they were in past years. Prevention efforts should be targeted at delaying alcohol use in early adolescence.
 
Article
The prevalence and patterns of alcohol use and alcohol-related problems were determined in two large representative samples of 7-12th grade students in New York State in 1983 and 1990. Comparable sampling procedures and measures were used in both surveys. Logistic regression analyses showed that overall drinking, heavy drinking, and alcohol-related problems decreased significantly for the population as a whole; furthermore, all subgroups according to age, gender, and racial/ethnic status showed significant declines in alcohol use and related problems over this time period. The social context of this change is discussed.
 
Article
Genetic selection of rats can markedly alter their ethanol consumption. The manner in which environmental factors interact in these genetically selected animals to influence ethanol consumption has not been thoroughly investigated. Using the alcohol-nonpreferring (NP) line of rats selectively bred at the Indiana University School of Medicine, alcohol self-administration in an operant situation was initiated using either a sucrose-fading or a secondary-conditioning procedure. These initiation procedures do not require any food or fluid restriction. Initiation was successful in 10 out of 12 NP animals, with the initiated rats self-administering ethanol at concentrations as high as 40%. Following initiation, a retest of home-cage ethanol preference found increases in ethanol acceptability. When tested in a concurrent operant situation, the initiated NP rats also chose ethanol over water. However, the NP rats had lower alcohol intakes and a different pattern of drinking over time when compared to that of nonselected Long-Evans rats. While the NP rats could be initiated to lever-press for ethanol, at no time did their intake approach that of the selected line of alcohol-preferring (P) rats. Thus, while an upward shift from the genetic baseline in ethanol preference and intake can result from the environmental initiation manipulations employed in these studies, genetic factors would appear to limit the extent to which ethanol ingestion can be increased.
 
Article
Research has shown that adolescents who begin drinking at an early stage in life are at greater risk of developing alcohol dependency, as well as a variety of negative outcomes, for instance, delinquent behavior. Most of these studies have focused on those who begin drinking in middle adolescence, but little attention has been paid to youth who initiate drinking under the age of 13. Twenty percent of adolescents have begun using alcohol by the age of 13. The purpose of the study is to examine whether initiating alcohol use before the age of 13 exacerbates negative outcomes in late adolescence. Data for the study were derived from 2 school-based statewide surveys conducted in Florida: the 2005 YRBS and the 2006 FYSAS. The sample included 12,352 11th and 12th grade students divided into 3 groups: students who initiated alcohol use under the age of 13, students who initiated alcohol use at age 13 or later, and students who never used alcohol. Results showed that after adjusting for gender, ethnicity/race, and grade, adolescents who initiated alcohol use before age 13 were more likely to report problems with school performance and display delinquent behaviors (carrying a gun, carrying a weapon to school, and recent marijuana use). Although no temporal relationships can be determined between drinking alcohol before age 13 and delinquent behavior outcomes, the results suggested that adolescents under the age of 13 need to be included in national epidemiological surveys on alcohol use and more efforts need to be directed toward the implementation of prevention programs early in elementary and middle schools.
 
Article
There are few functional tests for liver function that selectively indicate the toxic effect of alcohol abuse. To explore the long-term impact of excessive alcohol use on the liver, there is a need for such specific analyses. The Ketoisocaproate breath test has been shown to be a specific marker of mitochondrial function in the liver, which is known to be selectively affected by heavy alcohol intake. This method was evaluated by analyzing 13 male patients with severe alcohol dependence and comparing these with 10 healthy volunteers, 5 women and 5 men. All alcoholic patients reported a heavy intake of alcohol during the last month before the test and all had some form of abnormal liver status as assessed by traditional markers such as aspartate aminotransferase, alanine aminotransferase, or gamma-glutamyltransferase analyses. The results showed that healthy women had a higher percentage exhalation of 13CO2 than both healthy males and alcoholic males. In contrast to previous studies, we found no significant impairment of Ketoisocaproate decarboxylation as an effect of chronic intake of alcohol or alcohol-induced steatosis. The findings could not be explained completely by concurrent drug intake used in the routine detoxification of the patients. Thus, the value of the Ketoisocaproate breath test as a biological marker of excessive alcohol consumption appears to be limited because of a fast normalization of the values.
 
Article
Background: Using an experimental model of airway fibrosis following lung transplantation, we recently showed that chronic alcohol ingestion by donor rats amplifies airway fibrosis in the recipient. Associated with alcohol-mediated amplification of airway fibrosis is increased transforming growth factor beta-1(TGFbeta(1)) and alpha-smooth muscle actin expression. Other studies have shown that interleukin-13 (IL-13) modulates TGFbeta(1) signaling during experimentally-induced airway fibrosis. Therefore, we hypothesized that IL-13 is a component of alcohol-mediated amplification of pro-fibrotic mediators in the alcoholic lung. Methods: To test this hypothesis, we analyzed tracheal epithelial cells and type II alveolar cells from control- or alcohol-fed rats, alcohol-treated mouse lung fibroblasts, and human bronchial epithelial cells in vitro for expression of various components of the IL-13 signaling pathway. Signaling via the IL-13 pathway was assessed by measuring levels of phosphorylated signal transducers and activators of transcription-6 (STAT6). In addition, we performed heterotopic tracheal transplantation using control-fed and alcohol-fed donor rats and analyzed tracheal allografts for expression of components of the IL-13 signaling pathway by RT-PCR and immunocytochemical analyses. Results: Interleukin-13 expression was detected in type II alveolar epithelial cells and human bronchial epithelial cells, but not in lung fibroblasts. IL-13 expression was decreased in whole lung and type II cells in response to alcohol exposure. In all cell types analyzed, expression of IL-13 signaling receptor (IL-13R alpha(1)) mRNA was markedly increased. In contrast, mRNA and protein expression of the IL-13 decoy receptor (IL-13R alpha(2)) were decreased in all cells analyzed. Exposure to alcohol also increased STAT6 phosphorylation in response to IL-13 and lipopolysaccharide. Conclusions: Data from multiple cell types in the pulmonary system suggest that IL-13 and its receptors play a role in alcohol-mediated activation of pro-fibrotic pathways. Taken together, these data suggest that alcohol primes the airway for increased IL-13 signaling and subsequent tissue remodeling upon injury such as transplantation.
 
Article
Background: Prevention programs often aim at preventing early onset of drinking (EOD) on the grounds that this may curb heavy drinking in adulthood. While many studies have shown an association between EOD and adult alcohol use disorders, these findings could be inflated by retrospective reports or insufficient control for confounders. This study examined the association between EOD behavior assessed in early adolescence and heavy drinking in adulthood, controlling for deviant behavior and parental heavy drinking. Methods: Data were collected prospectively over a 13-year period from 1,311 Norwegian school students. At t1 (ages 13 to 14 years), onset of drinking behavior (any drinking and heavy episodic drinking), conduct problems (CP), other problem behaviors, and parental heavy drinking were assessed. At t2 (ages 26 to 27 years), heavy drinking behavior was assessed in terms of heavy episodic drinking frequency and AUDIT score. Results: EOD behavior was associated with CP, other problem behaviors, and parental heavy drinking in early adolescence. A higher risk of heavy drinking in adulthood was found among those with EOD behavior, yet after control for CP, this association became small and statistically nonsignificant. Among low-risk individuals (i.e., those with no CP at t1), there was no association between EOD behavior and heavy drinking in adulthood, while there was a significant association among those with CP. Conclusions: EOD behavior appears not per se responsible for heavy drinking in adulthood unless being part of a broader array of problem behaviors.
 
Top-cited authors
Kathleen K Bucholz
  • Washington University in St. Louis
Edith V Sullivan
  • Stanford Medicine
Henry Kranzler
  • University of Pennsylvania
Susan Tapert
  • University of California, San Diego
Howard Edenberg
  • Indiana University School of Medicine