Single Dose Of Ethanol Research Articles

Drug interaction between ethanol and 3,4-methylenedioxymethamphetamine (“ecstasy”)

Alcohol (ethanol) and 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) are frequently co-abused, but recent findings indicate a harmful drug interaction between these two agents. In our previous study, we showed that MDMA exposure inhibits the activity of the acetaldehyde (ACH) metabolizing enzyme, aldehyde dehydrogenase2 (ALDH2). Based on this finding, we hypothesized that the co-administration of MDMA and ethanol would reduce the metabolism of ACH and result in increased accumulation of ACH. Rats were treated with MDMA or vehicle and then administered a single dose of ethanol. Liver ALDH2 activity decreased by 35% in the MDMA-treated rats compared to control rats. The peak concentration and the area under the concentration versus time curve of plasma ACH were 31% and 59% higher, respectively, in the MDMA-ethanol group compared to the ethanol-only group. In addition, the MDMA-ethanol group had 80% higher plasma transaminase levels than the ethanol-only group, indicating greater hepatocellular damage. Our results not only support a drug interaction between MDMA and ethanol but a novel underlying mechanism for the interaction.

Activation of ERK1/2 MAP kinase in rat liver in vivo after binge and chronic‐binge ethanol intake may augment liver injury

Liver injury caused by heavy alcohol consumption progresses from steatosis to steatohepatitis in some individuals. Binge ethanol intake is important factor in the progression to steatohepatitis in chronic alcoholics. Recent studies have implicated activation of extracellular regulated kinases (ERK1/2) to the actions of ethanol in cultured hepatocytes. In the present study, role of of ERK1/2 was examined in a clinically relevant animal model of progressive liver injury. This involved chronic ethanol administration for 4 weeks followed by a binge dose of ethanol (chronic‐binge) that culminated in an amplified liver injury. Eight week old Sprague Dawley rats were fed ethanol in liquid diet for 4 weeks followed by single binge dose of ethanol (5 gm/kg body weight) through intragastric administration for 4 hrs. Control rats were pair‐fed isocaloric diet. In the control for the binge ethanol was replaced by water. Chronic ethanol treatment (4 weeks) resulted in mild steatosis and necrosis whereas chronic‐ binge group exhibited marked steatosis and significant increase (2 fold) in necrosis. Chronic ‐ binge group also showed significant increase (2 to 3 fold) in the phospho‐ERK1/2 in liver with negligible effect on ERK1/2 protein level. Activation of ERK1/2 was not significant in the liver of ethanol alone treated group compared to control group. Taken together, these results suggest that activation of ERK1/2 by binge ethanol may augment steatosis and necrosis in liver. Supported by NIH grant AA 11962.

Effects of ethanol administration on brain neurotensin-like immunoreactivity in rats.

The effects of acute and chronic ethanol administration on neurotensin-like immunoreactivity (NTLI) were investigated in discrete regions of the rat brain. Rats were administered a single dose (5 g/kg) of ethanol or rendered ethanol-dependent by repeated forced drinking of a 20% ethanol solution (6-15 g/kg) for 4 days and tested while still intoxicated or at 12-19 h (W-1) or 7 days (W-2) after ethanol withdrawal. Increases in NTLI were seen in the caudate-putamen in the toxic, W-1 and W-2 groups and decreases were observed in the midbrain in the toxic and W-1 groups. It was assumed that ethanol produced the changes of NTLI in the caudate-putamen and midbrain through its actions upon the dopaminergic system.

Prediction of the Effect of Injected Ethanol on Pulmonary Arterial Pressure during Sclerotherapy of Arteriovenous Malformations: Relationship with Dose of Ethanol

To prospectively evaluate the effect of injected ethanol on pulmonary artery pressure during embolosclerotherapy of arteriovenous malformations (AVMs). This prospective study was conducted in 16 male and 14 female patients (37 sessions; mean age, 34 years; age range, 17-67 years) with AVMs during a 2-year period. The authors measured pulmonary artery pressure via a pulmonary artery catheter and ethanol levels from the pulmonary and radial arteries simultaneously within 3 minutes after each ethanol injection. The authors analyzed the relationship between pulmonary artery pressure and ethanol levels obtained from pulmonary and radial arteries with respect to both single and cumulative doses of ethanol injected. Retrospectively, patients were divided into two groups-those treated with and those treated without vascular occlusion techniques. The radial arterial ethanol level showed good correlation with the pulmonary arterial ethanol level (r = 0.7). Single dose per injection was statistically related with pulmonary artery pressure (r = 0.5 vs 0.1 and P < .05 vs .29, respectively, in patients treated without and patients treated with vascular occlusion techniques), and the correlation coefficient between cumulative dose and pulmonary artery pressure was 0.2 and 0.3 in respective cases (P < .05 for both). The mean pulmonary artery pressure correlated with pulmonary arterial ethanol level irrespective of the use of vascular occlusion (r = 0.6 for both groups). Pulmonary artery pressure reflected the pulmonary arterial ethanol level and was positively related to the dose of ethanol. Single dose per injection was predictive of pulmonary artery pressure only in patients treated without vascular occlusion techniques.

Alcohol significantly lowers the seizure threshold in mice when co-administered with bupropion hydrochloride

BackgroundBupropion HCl is a widely used antidepressant that is known to cause seizures in a dose-dependent manner. Many patients taking antidepressants will consume alcohol, even when advised not to. Previous studies have not shown any interactions between bupropion HCl and alcohol. However, there have been no previous studies examining possible changes in seizure threshold induced by a combination of alcohol and bupropion HCl.MethodsExperimentally naïve female Swiss albino mice (10 per group) received either single doses of bupropion HCl (ranging from 100 mg/kg to 120 mg/kg) or vehicle (0.9% NaCl) by intraperitoneal (IP) injection in a dose volume of 10 ml/kg, and single-dose ethanol alone (2.5 g/kg), or vehicle, 5 min prior to bupropion dosing. The presence or absence of seizures, the number of seizures, the onset, duration and the intensity of seizures were all recorded for 5 h following the administration of ethanol.ResultsThe results show that administration of IP bupropion HCl alone induced seizures in mice in a dose-dependent manner, with the 120 mg/kg dose having the largest effect. The percentage of convulsing mice were 0%, 20%, 30% and 60% in the 0 (vehicle), 100, 110, and 120 mg/kg dose groups, respectively. Pretreatment with ethanol produced a larger bupropion HCl-induced convulsive effect at all the doses (70% each at 100, 110 and 120 mg/kg) and a 10% effect in the ethanol + vehicle only group. The convulsive dose of bupropion HCl required to induce seizures in 50% of mice (CD50), was 116.72 mg/kg for bupropion HCl alone (CI: 107.95, 126.20) and 89.40 mg/kg for ethanol/bupropion HCl (CI: 64.92, 123.10).ConclusionThese results show that in mice alcohol lowers the seizure threshold for bupropion-induced seizures. Clinical implications are firstly that there may be an increased risk of seizures in patients consuming alcohol, and secondly that formulations that can release bupropion more readily in alcohol may present additional risks to patients.

Ethanol induces stronger dopamine release in nucleus accumbens (shell) of alcohol-preferring (bibulous) than in alcohol-avoiding (abstainer) rats

Several studies on the differences between ethanol-preferring versus non-preferring rat lines suggest an innate deficit in the mesolimbic dopaminergic system as an underlying factor for ethanol volition. Rats would try to overcome such deficit by engaging in a drug-seeking behaviour, when available, to drink an ethanol solution over water. Thus, in the present study we compared the effect of a single dose of ethanol (1 g/kg, i.p.) on the extracellular levels of monoamines measured by microdialysis in the shell of nucleus accumbens of University of Chile bibulous (UChB) and University of Chile Abstainer (UChA) rats, bred for 79 and 88 generations to prefer or reject ethanol, respectively. It is reported that under basal conditions extracellular dopamine levels are lower in the bibulous than in the abstainer rats, while ethanol induced a 2-fold greater increase of dopamine release in bibulous than in abstainer rats. The greater effect of ethanol in bibulous rats was not associated to differences in blood ethanol levels, since the concentration and elimination of ethanol were virtually identical in both rat lines, indicating that bibulous rats are more sensitive to the stimulation of dopamine release by ethanol than abstainer rats. No differences were observed in 5-hydroxytryptamine or metabolites measured simultaneously under basal or ethanol-stimulating conditions in bibulous and abstainer rats. Overall, the present results suggest that a low dopaminergic tone and a strong mesolimbic dopamine response to ethanol are concerted neurochemical features associated to an ethanol-seeking behaviour in rats.

Fish oil fed prior to ethanol administration prevents acute ethanol-induced fatty liver in mice

We examined whether dietary fish oil can prevent acute ethanol (alcohol)-induced fatty liver. Mice were fed safflower oil, fish oil, or safflower oil plus a PPAR alpha activator on the day prior to ethanol administration. Oil red O staining, serum analysis, and RT-PCR were used to analyze ethanol-induced fatty liver. In mice fed safflower oil, ethanol increased liver TG 3-fold, with activation of SREBP-1c and ChREBP, which promote de novo lipogenesis, and increases in expression of mRNAs for PPAR gamma and DGATs mRNAs, which promote TG synthesis. When mice were fed fish oil, ethanol-induced fatty liver was reduced by 73%. Fish oil decreased SREBP-1c activity and increased PPAR alpha activity. However, levels of DGAT1, DGAT2, ChREBP, LPK, and PPAR gamma mRNAs were increased in response to ethanol in mice fed fish oil. Prior administration of Wy14643, PPAR alpha activator, did not inhibit ethanol-induced fatty liver, suggesting that PPAR alpha played little role in prevention of ethanol-induced fatty liver by fish oil. A single dose of ethanol increases the liver TG level via several mechanisms; however, prior ingestion of fish oil effectively prevents ethanol-induced fatty liver, at least in part, by decreasing basal SREBP-1c activity, especially a marked reduction in SCD1.

Acute ethanol exposure disrupts VEGF receptor cell signaling in endothelial cells

Physiological angiogenesis is regulated by various factors, including signaling through vascular endothelial growth factor (VEGF) receptors. We previously reported that a single dose of ethanol (1.4 g/kg), yielding a blood alcohol concentration of 100 mg/dl, significantly impairs angiogenesis in murine wounds, despite adequate levels of VEGF, suggesting direct effects of ethanol on endothelial cell signaling (40). To examine the mechanism by which ethanol influences angiogenesis in wounds, we employed two different in vitro angiogenesis assays to determine whether acute ethanol exposure (100 mg/dl) would have long-lasting effects on VEGF-induced capillary network formation. Ethanol exposure resulted in reduced VEGF-induced cord formation on collagen and reduced capillary network structure on Matrigel in vitro. In addition, ethanol exposure decreased expression of endothelial VEGF receptor-2, as well as VEGF receptor-2 phosphorylation in vitro. Inhibition of ethanol metabolism by 4-methylpyrazole partially abrogated the effect of ethanol on endothelial cell cord formation. However, mice treated with t-butanol, an alcohol not metabolized by alcohol dehydrogenase, exhibited no change in wound vascularity. These results suggest that products of ethanol metabolism are important factors in the development of ethanol-induced changes in endothelial cell responsiveness to VEGF. In vivo, ethanol exposure caused both decreased angiogenesis and increased hypoxia in wounds. Moreover, in vitro experiments demonstrated a direct effect of ethanol on the response to hypoxia in endothelial cells, as ethanol diminished nuclear hypoxia-inducible factor-1alpha protein levels. Together, the data establish that acute ethanol exposure significantly impairs angiogenesis and suggest that this effect is mediated by changes in endothelial cell responsiveness to both VEGF and hypoxia.

Acute ethanol induces Fos in GABAergic and non-GABAergic forebrain neurons: A double-labeling study in the medial prefrontal cortex and extended amygdala

The purpose of this study was to further address the hypothesis that ethanol activates GABAergic neurons in specific brain neurocircuits that mediate motivated behavior and control of action, such as the central extended amygdala and medial prefrontal cortex. Male Sprague–Dawley rats received habituation to 7 days of daily intragastric administration of water (5 ml/kg) followed by a single acute intragastric dose of ethanol (2.5 g/kg) or water then, 2 h later, by paraformaldehyde perfusion. Rats left undisturbed in the animal room throughout the experiment were also perfused (naive group). Brain sections were processed for single Fos immunohistochemistry or dual Fos immunohistochemistry/glutamic acid decarboxylase (GAD) mRNA in situ hybridization. Intragastric water administration increased the number of Fos-immunoreactive cells in the infralimbic cortex and lateral part of the central nucleus of the amygdala compared with the naive group. Ethanol administration increased the number of Fos-immunoreactive cells in the infralimbic (+57.5%) and prelimbic (+105.3%) cortices, nucleus accumbens shell region (+88.2%), medial part of the central nucleus of the amygdala (+160%), and lateral part of the bed nucleus of the stria terminalis (+198.8%) compared with the water-treated group. In the nucleus accumbens shell region, central nucleus of the amygdala, and bed nucleus of the stria terminalis, more than 80% of Fos-immunoreactive neurons were GABAergic after ethanol administration. In contrast, in the prelimbic cortex, 75% of Fos-immunoreactive neurons were not GABAergic. These results constitute new evidence for region-specific functional interactions between ethanol and GABAergic neurons.

Acute tolerance to rate-decreasing effects of single doses of ethanol

Acute tolerance occurs when behavioral impairment is greater at a given blood ethanol concentration (BAC) on the ascending versus descending limb of the BAC–time curve following administration of a single dose of ethanol, however studies utilizing learned behaviors have not been widely reported. We assessed acute tolerance to single doses of ethanol in five Lewis rats responding under a fixed-ratio (FR8) schedule of food presentation. Response rates for food during 1-min components (ending 2, 4, 11, 18, 33, and 57 min after ethanol administration) were determined, and BAC was measured immediately after each component using a rat breathalyzer. Ethanol (0.4, 0.6, 0.8, and 1.2 g/kg, i.p.) produced dose-related decreases in responding for food that tended to recover over time for all but the highest dose tested. Similarly, dose-related increases in BAC were also observed. Using either an analysis that expressed impairment per unit BAC on the ascending limb versus the descending limb (by assessing the area under the curve (AUC) for behavior and BAC on each limb), the slope of the function that relates the behavioral effect to BAC (each expressed as percent maximum effect), or a variant of the Mellanby method (hysteresis), acute tolerance was observed following a dose of 0.4 g/kg ethanol. Though behavior appeared to recover on the descending limb following higher doses (especially 0.6 and 0.8 g/kg), acute tolerance to these doses was not present.

Overview of Mouse Assays of Ethanol Intoxication

There are many behavioral assays to assess sensitivity to ethanol intoxication in mice. Most are simple to implement, and are sensitive to a particular dose range of ethanol. Most reflect genetic influences, and each test appears to reflect the contribution of a relatively distinct collection of genes. This genetic heterogeneity implies that no single test can claim to capture the construct "ethanol intoxication" completely. Depending on the test, and when measurements are made, acute functional tolerance to even a single dose of ethanol must be considered as a contributing factor. Whether or not a test is conducted in naïve mice or as part of a test battery can influence sensitivity, and do so in a strain-dependent manner. This unit reviews existing tests and recommends several.

Protective and therapeutic effects of an extract mixture of alder tree, labiate herb, milk thistle green bean-rice bran fermentation, and turnip against ethanol-induced toxicity in the rat

An herbal extract mixture and yogurt added to the herbal extract mixture were tested for their protective and therapeutic effects on ethanol-induced liver injury. The herbal extract mixture, yogurt and commercial drugs were used for treatment for two weeks prior to administering a single oral dose of ethanol (3 g/kg body weight). The herbal extract mixture and yogurt added to the herbal extract mixture were found to provide protection against ethanol-induced toxicity comparable to the commercial drug treatment, according to the serum and histopathological analysis. It was also shown that co-treatment with herbal extract mixture and yogurt against a triple oral dose of ethanol (2 g/kg body weight, over one week) provided protection against ethanol toxicity. After the initial set of experiments, the herbal extract mixture and yogurt treatments were extended for three more weeks. When compared to the positive control, further treatment with both the herbal extract and yogurt significantly reduced liver injury and resulted in a lower grade of lipid deposition.

1H NMR-Based Metabolomic Analysis of Liver, Serum, and Brain Following Ethanol Administration in Rats

Ethanol is a widely used drug that is consumed in large amounts for pharmacologic effects. Elimination of ethanol alters metabolism in the liver and throughout an organism. Ethanol's effect on metabolites can influence the regulation of key pathways such as gluconeogenesis. We adopted a proton NMR-based metabolomic approach to study ethanol-induced metabolic changes in liver, blood, and brain tissue from rats exposed to either a single dose of ethanol or a chronic 4 day binge-ethanol protocol. Both acute and binge ethanol caused (i) decreased glucose, lactate, and alanine in liver and serum; (ii) increased acetate in liver and serum; and (iii) increased acetoacetate in serum. Binge-ethanol increased liver beta-hydroxybutyrate and decreased betaine. Pretreatment with the antioxidant butylated hydroxytoluene (BHT) increased betaine and reduced ethyl glucuronide (EtG) in livers of binge-ethanol animals, as compared to those not pretreated with BHT. We found no change in brain metabolites after a single dose of ethanol. Unsupervised principal component (PC) analysis of spectral data from liver and serum successfully discriminated treatment groups, based largely on the biochemical differences outlined above, confirming the results of manual analysis. To explain the observed lack of gluconeogenesis following ethanol treatment and to resolve apparently discordant results from previous studies, we propose a model in which decreased hepatic alanine removes inhibition on pyruvate kinase, thus permitting a futile cycle that diverts phosphoenolpyruvate away from gluconeogenesis. This is a new mechanism that biochemically elucidates the well-known, yet unexplained, "empty calorie" phenomenon of ethanol. Reduction of EtG by pretreatment with BHT suggests that BHT and perhaps other compounds may alter the pharmacokinetics of EtG so that EtG may not always be a sensitive marker for ethanol abuse.

Severity of alcohol withdrawal symptoms depends on developmental stage of Long–Evans rats

To investigate alcohol dependency and the potential role of age of initial alcohol consumption, Long–Evans (LE) rats were fed an ethanol-containing liquid diet starting at postnatal (P) ages (days): P23–27 (juvenile), P35–45 (adolescent) or P65–97 (young adult). Severity of subsequent withdrawal symptoms was dependent on age when consumption began and on duration of alcohol consumption. Frequency of withdrawal seizures was highest for rats starting consumption as juveniles, intermediate for adolescents and lowest for adults. Normalized to body weight, alcohol consumption was significantly higher for adolescent and juvenile rats than for adults. Sprague–Dawley rats that began alcohol consumption as adolescents (P35) had a level of alcohol consumption identical to that of the adolescent LE rats but showed much lower frequency of withdrawal seizures when tested after 2, 3 and 5 weeks of alcohol consumption. Based on several indicators, the capacity of the juveniles to metabolize ethanol is equal to or exceeds that of adults. Recoveries from a single dose of ethanol (2.5 g ethanol/kg body weight) were faster for juvenile LE rats than adults. The rate of decline in blood ethanol concentration was identical for juvenile and adult rats while the corrected ethanol elimination rate was higher for juveniles. The primary isozyme of alcohol dehydrogenase (ADH) in rat liver, ADH-3, had a similar Km and higher activity in liver preparations from juveniles. In conclusion, LE rats beginning alcohol consumption as juveniles or adolescents develop a severe alcohol withdrawal syndrome that may not be attributed entirely to higher levels of consumption and was not explained by any obvious deficiencies in metabolism.

Relative Abuse Liability of γ-Hydroxybutyric Acid, Flunitrazepam, and Ethanol in Club Drug Users

Despite the increasing concern about gamma-hydroxybutyric acid (GHB) toxicity, there are few studies examining the clinical pharmacology of GHB and its abuse potential. To evaluate GHB-induced subjective and physiological effects, its relative abuse liability and its impact on psychomotor performance in club drug users. Twelve healthy male recreational users of GHB participated in 5 experimental sessions in the framework of a clinical trial. The study was randomized, double-blind, double-dummy, and crossover. Drug conditions were a single oral dose of GHB (40 or 60 mg/kg), ethanol (0.7 g/kg), flunitrazepam (1.25 mg), and placebo. Study variables included vital signs (blood pressure, heart rate, oral temperature, pupil diameter), psychomotor performance (digit symbol substitution test, balance, Maddox-Wing), subjective effects (a set of 13 visual analogue scales, Addiction Research Center Inventory-49 items, and Evaluation of the Subjective Effects of Substances with Potential of Abuse questionnaires), and pharmacokinetics. All active conditions induced positive effects related to their abuse potential. The administration of GHB produced euphoria and pleasurable effects with slightly higher ratings than those observed for flunitrazepam and ethanol. Gamma-hydroxybutyric acid induced a biphasic time profile with an initial stimulant-like effect related to the simultaneous rise of plasma concentrations and a latter sedative effect not related to GHB kinetics. Gamma-hydroxybutyric acid increased blood pressure and pupil diameter. Ethanol induced its prototypical effects, and flunitrazepam produced marked sedation. Gamma-hydroxybutyric acid and flunitrazepam impaired psychomotor performance, digit symbol substitution test, and balance task, whereas ethanol, at the dose tested, induced only mild effects exclusively affecting the balance task. Our results suggest a high abuse liability of GHB and flunitrazepam in club drug users.

Single-dose ethanol administration downregulates expression of cytochrome p450 2E1 mRNA in aldehyde dehydrogenase 2 knockout mice

The polymorphism of aldehyde dehydrogenase 2 ( ALDH2), denoted ALDH2*2, is very common in East Asian origin. Acetaldehyde, an intermediate metabolite of ethanol, is metabolized very slowly in people with ALDH2*2 because the mutant ALDH2 protein lacks the activity of acetaldehyde metabolism. On the other hand, it is well established that one of the cytochrome P450 enzymes, CYP2E1, is an activator of carcinogens (e.g., nitorosamines) and a generator of oxidative stress, and it is shown that CYP2E1 was induced by ethanol via gene transcriptional regulation. In the present study, to examine the consequences of ALDH2 polymorphism on transcriptional regulation of CYP2E1 in liver tissue, Aldh2+/+ and Aldh2−/− mice were orally administered 5 g/kg body weight of ethanol and the levels of CYP2E1 mRNA in liver tissue then analyzed. The level of CYP2E1 mRNA 12 h after the ethanol administration tended to be higher than the 0-h group in Aldh2+/+ mice, however, it was significantly lower than the 0-h group in Aldh2−/− mice. These findings suggest that single-dose ethanol administration downregulates the expression of cytochrome p450 2E1 mRNA in the presence of inactive ALDH2.

The impact of gonadectomy and adrenalectomy on acute withdrawal severity in male and female C57BL/6J and DBA/2J mice following a single high dose of ethanol.

Steroid hormones can influence neuronal excitability and subsequent seizure susceptibility through genomic and nongenomic mechanisms. For example, there are proconvulsant steroids such as estradiol and corticosterone and anticonvulsant steroids such as testosterone, progesterone, and their GABAergic metabolites. Recent findings indicated that a single, acute administration of ethanol increased levels of GABAergic steroids and that the source of this increase was peripheral organs such as the adrenals and gonads. Thus, the purpose of the present study was to determine the impact of removal of the adrenals and/or gonads on withdrawal severity following a single high dose of ethanol in 2 genotypes that differ in ethanol withdrawal severity. Male and female C57BL/6J (B6) and DBA/2J (D2) mice were either left intact (SHAM), adrenalectomized (ADX), gonadectomized (GDX), or underwent ADX/GDX surgery. Seven days following surgery, baseline handling-induced convulsions (HICs) were measured prior to administration of a 4 g/kg dose of ethanol. HICs were assessed following the ethanol injection, then hourly for 12 hours and at 24 hours. A separate group of mice were used to measure the impact of surgical status on ethanol metabolism at 30, 60, 120, and 240 minutes after a single 4 g/kg dose of ethanol. ADX and ADX/GDX treatments in male B6 and D2 mice increased ethanol withdrawal severity following a single dose of ethanol, measured by area under the withdrawal curve and peak HIC scores. Acute ethanol withdrawal also was increased in female D2 mice that had undergone ADX/GDX. In contrast, surgical status did not alter ethanol withdrawal severity in female B6 mice. Surgical status had only minor effects on ethanol metabolism. Removal of peripherally derived steroids with anticonvulsant properties significantly increased HIC scores during acute ethanol withdrawal following a single dose of ethanol in male and female D2 mice and in male B6 mice. These increases were not due to changes in ethanol metabolism.

Dose‐ and Time‐Dependent Expression of Anxiety‐Like Behavior in the Elevated Plus‐Maze During Withdrawal From Acute and Repeated Intermittent Ethanol Intoxication in Rats

Withdrawal from acute bolus intraperitoneal (IP) injection of high doses of ethanol elicits anxiety-like behavior (e.g. Doremus et al., 2003; Gauvin et al., 1989, 1992) and conditioned place aversion (Morse et al., 2000). More recently we demonstrated that withdrawal from a single moderate dose of ethanol (2.0 g/kg) is accompanied by elevations in brain reward thresholds, and that repeated intermittent treatment with this dose results in a significant potentiation of reward deficit (Schulteis and Liu, 2006). In the current study, the time- and dose-dependent emergence of anxiety-like behavior was measured in the elevated plus-maze at various times (3 to 24 hours) after acute or 3 daily IP injections of ethanol (1.0, 2.0, or 3.0 g/kg). Rats receiving daily handling for 2 days, and a single anxiety opportunity to explore the maze on a third day were divided into 1 of several treatment protocols: (1) NAIVE conditions: vehicle IP on all 3 days; (2) ACUTE conditions: vehicle on the first 2 days, ethanol on the third day; or (3) REPEAT conditions: ethanol on all 3 days. ACUTE ethanol elicited reduced exploration of the open arms of the elevated plus-maze in a dose- and time-dependent fashion: 1.0 g/kg failed to elicit any significant effects, whereas 2.0 and 3.0 g/kg ethanol elicited a significant anxiety-like response at 6 hours and 9 to 12 hours postinjection, respectively. REPEAT treatment was still without effect at any time point tested following 1.0 g/kg ethanol, but extended the time course of anxiety-like behavior after treatment with either 2.0 or 3.0 g/kg doses. REPEAT treatment with 2.0 and 3.0 g/kg ethanol also produced significant hypoactivity in the maze at some time points postinjection. Withdrawal from a single exposure to ethanol produces transient but significant anxiety-like behavior, and repeated intermittent bouts of intoxication result in a significant extension of the duration of effect. The rapid emergence and progression of negative emotional signs of withdrawal may be a significant factor in determining susceptibility to transition from casual drinking to loss of control and escalating patterns of consumption that result in alcoholism.

Maternal Alcohol Consumption Increases Sphingosine Levels in the Brains of Progeny Mice

The effect of 'binge' alcohol upon sphingolipid metabolism in the fetal alcohol syndrome (FAS) was examined in pregnant mice (C57BL/6J) by administering a single dose of alcohol during the third trimester (gestational day 15-16). The control mice were administered a sucrose solution of equal caloric value. Brains from progeny at postnatal days 5, 15, 21 and 30 were dissected into three regions, and sphingolipid concentrations of the brain regions were determined including assay of monoglycosylceramide, ceramide, sphingosine and sphingomyelin. We found that a single dose of ethanol induces an elevation of sphingosine (2-3.5-fold) in the brain of progeny. The level of brain ceramide at a dose of 1.5 g/kg was significantly higher than control. Alcohol consumption during pregnancy induces neuronal loss in progeny brains. Our result suggests that the elevation of sphingosine in progeny brain induced by maternal alcohol consumption may be responsible for observed neuronal loss in FAS.

Acetaldehyde accumulation in rat mammary tissue after an acute treatment with alcohol

Previous studies reported the presence in rat mammary tissue of a cytosolic xanthine oxidoreductase pathway for the metabolism of alcohol to acetaldehyde and hydroxyl radicals and to the microsomal biotransformation of ethanol to acetaldehyde. It was also reported that after chronic ethanol drinking stressful oxidative conditions can be observed. The present work reports that even after single doses of ethanol, given at three different levels (6.3 g kg(-1); 3.8 g kg(-1) or 0.6 g kg(-1) p.o.), acetaldehyde accumulates for prolonged periods of time in the mammary tissue to reach concentrations higher than in blood (e.g. 5.1+/-1.2 nmol g(-1) versus 0.2+/-0.1 nmol ml(-1), for 6.3 g kg(-1) dose, 6 h after intoxication). The presence in rat mammary tissue of low activities of additional enzymes able to generate acetaldehyde was established (alcohol dehydrogenase: 0.97+/-0.84 mU mg(-1) protein; CYP2E1: 1.30+/-0.12 x 10(-2) pmol 4-nitrocatechol min(-1) mg(-1) protein) and a low activity of aldehyde dehydrogenase was observed in the cytosolic, mitochondrial and microsomal fractions (0.02+/-0.04; 0.35+/-0.09 and 0.72+/-0.19 mU mg(-1) protein, respectively). After a single high dose of ethanol, an increased susceptibility to oxidative stress was observed, as evidenced by changes in the shape of t-butylhydroperoxide induced emission of chemiluminescence in mammary tissue (6.3 g kg(-1) dose; at 3 and 6 h). In summary, the results show that even after single doses of ethanol, acetaldehyde, either formed in situ or arriving via blood, tends to accumulate in mammary tissue and that this condition might decrease cell defenses against injury.