Bolus Of Ethanol Research Articles

An iso-α-acid-rich extract from hops (Humulus lupulus) attenuates acute alcohol-induced liver steatosis in mice.

Results of invitro and invivo studies suggest that consumption of beer is less harmful for the liver than consumption of spirits. It also has been suggested that secondary plant compounds derived from hops such as xanthohumol or iso-α-acids may have beneficial effects on the development of liver diseases of various etiologies. The aim of this study was to determine whether iso-α-acids consumed in doses achieved by "normal" beer consumption have beneficial effects on health. Female C57 Bl/6J mice, pretreated for 4d with an iso-α-acid-rich extract (∼30% iso-α-acids from hops, 0.75mg/kg body weight), were fed one bolus of ethanol (6g/kg body weight intragastric) or an iso-caloric maltodextrin solution. Markers of liver damage, toll-like receptor-4 signaling, and lipid peroxidation were determined. Furthermore, the effect of isohumulone on the lipopolysaccharide-dependent activation of J774 A.1 macrophages, used as a model of Kupffer cells, was determined. In the liver, acute ethanol administration led to a significant accumulation of fat (∼10-fold), which was accompanied by significantly higher inducible nitric oxide synthase protein level, elevated nitric oxide production, and increased plasminogen activator inhibitor 1 protein concentration when compared to controls. In mice pretreated with iso-α-acids, these effects of alcohol were markedly attenuated. Pretreatment of J774 A.1 macrophages with isohumulone significantly attenuated lipopolysaccharide-induced mRNA expression of inducible nitric oxide synthase and interleukin-6 as well as the release of nitric oxide. Taken together, iso-α-acids markedly attenuated the development of acute alcohol-induced damage in mice.

Ethanolic Extract of Acanthopanax koreanum Nakai Alleviates Alcoholic Liver Damage Combined with a High-Fat Diet in C57BL/6J Mice

Alcoholic and nonalcoholic liver steatosis have an indistinguishable spectrum of histological features and liver enzyme elevations. In this study, we investigated the potential of the ethanolic extract of Acanthopanax koreanum Nakai (AK) to protect against experimental alcoholic liver disease in a mouse model that couples diet and daily ethanol bolus gavage. Fifty-six C57BL/6J mice were randomly divided into seven groups: normal control (NC), alcohol control (AC), alcohol/HFD control (AH), low-dose (1%) AK in alcohol group (ACL), high-dose (3%) AK in alcohol group (ACH), low-dose AK in alcohol/HFD group (AHL), and high-dose AK in alcohol/HFD group (AHH). The AH group showed more severe damage than the AC group in terms of biochemical and molecular data that were observed in this study. The administration of AK exerted remarkable effects in: plasma ALT (p < 0.0001), total lipid (p = 0.014), TG (p = 0.0037) levels; CPT-1α (p = 0.0197), TLR4 (p < 0.0001), CD14 (p = 0.0002), IL-6 (p = 0.0264) and MCP-1 (p = 0.0045) gene expressions; and ALDH (p < 0.0001) and CAT (p = 0.0076) activities. The data suggested that at least the high dose AK might confer protection against alcoholic liver damage combined with an HFD by accelerating lipid oxidation and alcohol metabolism and by suppressing the inflammatory response, including the TLR pathway.

The circadian Per1 and Per2 genes influence alcohol intake, reinforcement, and blood alcohol levels

BackgroundPerturbations in the function of core circadian clock components such as the Period (Per) family of genes are associated with alcohol use disorder, and disruptions in circadian cycles may contribute to alcohol abuse and relapse. This study tested ethanol consumption, reinforcement, and metabolism in mice containing functional mutations in Per1 and/or Per2 genes on an ethanol-preferring background, C57BL/6J mice. MethodsMice were tested in: (A) free-access intake with ascending concentrations of ethanol (2–16%, v/v), (B) conditioned place preference using ethanol (2g/kg for males; 2.5g/kg for females) vs. saline injections, (C) recovery of the righting reflex following a 4g/kg bolus of ethanol, and (D) blood ethanol levels 1h after a 2g/kg bolus of ethanol. ResultsAll Per mutant (mPer) mice showed increased ethanol intake and condition place preference compared to controls. There were also genotypic differences in blood ethanol concentration: in males, only mPer1 mice showed a significantly higher blood ethanol concentration than WT mice, but in females, all mPer mice showed higher blood ethanol levels than WT mice. ConclusionsMutation of either Per1 or Per2, as well as mutations of both genes, increases ethanol intake and reinforcement in an ethanol-preferring mouse model. In addition, this increase in ethanol seeking behavior seems to result both from a change in ethanol metabolism and a change in reward responding to ethanol, but not from any change in sensitivity to ethanol's sedating effects.

S-adenosylmethionine decreases the peak blood alcohol levels 3 h after an acute bolus of ethanol by inducing alcohol metabolizing enzymes in the liver

Introduction An alcohol bolus causes the blood alcohol level (BAL) to peak at 1–2 h post ingestion. The ethanol elimination rate is regulated by alcohol metabolizing enzymes, primarily alcohol dehydrogenase (ADH1), acetaldehyde dehydrogenase (ALDH), and cytochrome P450 (CYP2E1). Recently, S-adenosylmethionine (SAMe) was found to reduce acute BALs 3 h after an alcohol bolus. The question, then, was: what is the mechanism involved in this reduction of BAL by feeding SAMe? To answer this question, we investigated the changes in ethanol metabolizing enzymes and the epigenetic changes that regulate the expression of these enzymes during acute binge drinking and chronic drinking. Methods Rats were fed a bolus of ethanol with or without SAMe, and were sacrificed at 3 h or 12 h after the bolus. Results RT-PCR and Western blot analyses showed that SAMe significantly induced ADH1 levels in the 3 h liver samples. However, SAMe did not affect the changes in ADH1 protein levels 12 h post bolus. Since SAMe is a methyl donor, it was postulated that the ADH1 gene expression up regulation at 3 h was due to a histone modification induced by methylation from methyl transferases. Dimethylated histone 3 lysine 4 (H3K4me2), a modification responsible for gene expression activation, was found to be significantly increased by SAMe at 3 h post bolus. Conclusion These results correlated with the low BAL found at 3 h post bolus, and support the concept that SAMe increased the gene expression to increase the elimination rate of ethanol in binge drinking by increasing H3K4me2.

Efficacy of Milrinone versus Nitroglycerin in Controlling Pulmonary Arterial Hypertension Induced by Intravenous Injections of Absolute Ethanol in Anesthetized Dogs

To compare the attenuating effects of milrinone versus nitroglycerin on pulmonary artery pressure (PAP) increase caused by repeat intravenous bolus injection of absolute ethanol in anesthetized dogs. Twenty-four dogs were randomly distributed into three groups: a control group (group C), a nitroglycerin group (treated with a continuous infusion of nitroglycerin at 5.0 microg/kg/min; group N), and a milrinone group (treated with a continuous infusion of milrinone at 3.0 microg/kg/min after an initial bolus dose of 100 microg/kg; group M). Absolute ethanol (0.1 mL/kg) was injected at 10-minute intervals via a 5-F angiographic catheter advanced into the proximal portion of the inferior vena cava. Immediately before and after each intravenous injection of absolute ethanol, hemodynamic values were obtained through a pulmonary arterial catheter. Group M showed more stable hemodynamic values of systolic, mean, and diastolic PAP and pulmonary vascular resistance (PVR) compared with groups C and N. In addition, group M showed significantly higher values of cardiac output versus group C at 10 minutes after the 10th bolus of ethanol. After restoration of spontaneous breathing, group M also showed the least hemodynamic changes in systolic, mean, and diastolic PAPs and PVR among the groups. Although a continuous infusion of nitroglycerin or milrinone effectively prevented cardiovascular deterioration, milrinone was superior to nitroglycerin in managing the acute hemodynamic changes that resulted from repeated intravenous bolus injections of absolute ethanol (0.1 mL/kg) in healthy anesthetized dogs.

EFFECT OF BETAINE TREATMENT OF RATS FED AN ACUTE BOLUS OF ETHANOL AT 3 H AND 12 H POST BOLUS: A MICROARRAY ANALYSIS

Betaine, a methyl donor active in methionine metabolism, has been effective in preventing and reversing experimental alcohol liver disease. However, the metabolic and molecular biologic mechanisms involved in this prevention are only partially known. To further investigate how betaine modifies the effects of ethanol on the liver, rats were given an acute ethanol bolus with or without betaine and the results were compared to isocaloric dextrose fed controls 3 h and 12 h post bolus. Livers were subjected to microarray analysis and functional pathways, and individual gene expression changes were analyzed. Experimental groups were compared by Venn diagrams showing that both ethanol and betaine caused a change in the expression of a large number of genes, indicating that the changes were global in extent. KEGG functional pathways were all affected and were mainly down regulated at 3 h post bolus when ethanol plus betaine were compared with ethanol fed rats. The most profound effect of betaine was on the metabolic pathways both at 3 and 12 h post bolus. At 3 h the changes in gene expression were mostly down regulated but at 12 h the changes were equally up and down regulated. Thus the effect of betaine on the effects of ethanol were partly transient. Supported by NIH/NIAAA 8116.

The effects of betaine treatment on rats fed an acute bolus of ethanol at 3 and 12 h post bolus: a microarray analysis

Betaine, a methyl donor active in methionine metabolism, is effective in preventing and reversing experimental alcohol liver disease. The metabolic and molecular biologic mechanisms involved in this prevention are only partially known. To further investigate how betaine modifies the effects of ethanol on the liver, rats were given an acute ethanol bolus with or without betaine and the results were compared to isocaloric dextrose-fed controls. Livers were subjected to microarray analysis, and functional pathways and individual gene expression changes were analyzed. Experimental groups were compared by Venn diagrams showing that both ethanol and betaine caused a change in the expression of a large number of genes indicating that the changes were global. The bio-informatic analysis showed that all the KEGG functional pathways were affected and mainly down regulated at 3 h post bolus when ethanol plus betaine were compared with ethanol-fed rats. The most profound effect of betaine was on the metabolic pathways both at 3 and 12 h post bolus. At 3 h, the changes in gene expression were mostly down regulated, but at 12 h, the changes were regulated equally up and down. This hypothesis-driven analysis showed that the effects of betaine on the effects of ethanol were partly transient.

Gene expression modifications in the liver caused by binge drinking and S-adenosylmethionine feeding. The role of epigenetic changes.

Chronic ethanol ingestion, achieved by feeding ethanol at a constant rate using intragastric tube feeding, alters the expression of genes in the liver. This is done by epigenetic mechanisms, which depend on the blood alcohol levels at the time of killing. However, acute bolus feeding of ethanol changes gene expression without lasting epigenetic changes. This occurs with histone 3 methylation and acetylation modifications. The gene expression response to an acute bolus of ethanol might be modified by feeding S-adenosylmethionine (SAMe), a methyl donor. In the present study, rats were given a bolus of ethanol (6 g/kg body weight (bw), SAMe (1 g/kg bw), ethanol + SAMe, or isocaloric glucose. The group of rats (n = 3) were killed at 3 and 12 h post bolus, and gene microarray analysis was performed on their liver cells. SAMe reduced the 3 h blood ethanol levels and increased the ALT levels at 3 h. Venn diagrams showed that alcohol changed the expression of 646 genes at 3 h post bolus and 586 genes at 12 h. SAMe changed the expression of 1,012 genes when fed with ethanol 3 h post ethanol bolus and 554 genes at 12 h post ethanol bolus. SAMe alone changed the expression of 1,751 genes at 3 h and 1,398 at 12 h. There were more changes in gene expression at 3 h than at 12 h post ethanol when ethanol alone was compared to the dextrose control. The same was true when SAMe was compared to SAMe + ethanol. Ethanol up regulated gene expression in most functional pathways at 3 h. However, when SAMe was fed with ethanol at 3 h, most pathways were down regulated. At 12 h, however, when ethanol was fed, the pathways were half up regulated and half down regulated. The same was true when SAMe + ethanol was fed. The expression of epigenetically important genes, such as BHMT and Foxn3, was up regulated 3 h post alcohol bolus. At 3 h, SAMe down regulated the expression of genes, such as BHMT, Mat2a, Jun, Tnfrs9, Ahcy 1, Tgfbr1 and 2, and Pcaf. At 12 h, the insulin signaling pathways were half down regulated by ethanol, which was partly prevented by SAMe. The MAPK pathway was up regulated by ethanol, but SAMe did not prevent this. In conclusion, profound changes in gene expression evolved between 3 h and 12 post ethanol bolus. SAMe down regulated these changes in gene expression at 3 h, and less so at 12 h.

Comparison of cardiopulmonary hemodynamic changes according to different ethanol bolus injection doses in piglets: the applicability of the study of ethanol injection effects on cardiopulmonary hemodynamic changes in sclerotherapy of congenital arteriovenous malformations

Background: Ethanol injection during a sclerotherapy for the treatment of arteriovenous malformation, which performed under general anesthesia, can cause significant hemodynamic changes, even cardiovascular collapse. However, guideline for adequate management of hemodynamic change or preventing detrimental complication has still not been proposed. Methods: Twenty-two piglets were randomly allocated to one of two groups: a 2.5 ml and a 4.0 ml ethanol. After baseline hemodynamic measurements, 2.5 ml or 4.0 ml of absolute ethanol was repeatedly administered in distal portion of renal vein with 10 minute intervals, and hemodynamic parameters were measured immediately before and after bolus injection of absolute ethanol until 10 minutes after final injection. Results: Compared with 2.5 ml group, systolic, mean and diastolic pulmonary arterial pressures (PAP) and pulmonary vascular resistance (PVR) of 4.0 ml group showed significant differences from the first bolus injection of absolute ethanol. Hemodynamic parameters of 2.5 ml group did not show the increasing or decreasing tendency during a session, whereas, in 4.0 ml group, systolic, mean and diastolic PAP and PVR showed significantly increasing tendency. However, systemic arterial blood pressure, heart rate, central venous pressure, pulmonary capillary wedge pressure, cardiac output, and systemic vascular resistance did not show increasing or decreasing tendency in both groups. Conclusions: Based on the hemodynamic alterations observed from piglet model, the bolus injection of absolute ethanol during sclerotherapy in congenital arteriovenous malformation requires careful hemodynamic monitoring. We strongly recommend that anesthesiologist should carefully monitor the hemodynamic parameters after injection of relatively large amount of absolute ethanol.

14-methoxymetopon, a highly potent μ opioid agonist, biphasically affects ethanol intake in Sardinian alcohol-preferring rats

Increased opioidergic activity is thought to increase the propensity to consume ethanol. However, the dose monotonicity and receptor subtype for this effect remain uncertain. 14-methoxymetopon is a centrally acting, selective micro opioid receptor agonist with greater systemic antinociceptive potency than morphine and a putatively improved therapeutic index. To determine whether 14-methoxymetopon influenced voluntary ethanol intake in Sardinian alcohol-preferring (sP) rats. Male sP rats with continuous 2-bottle choice access to ethanol (10% v/v) or water were subjects. The effects of systemic 14-methoxymetopon administration (2, 5, 12.25, 30 micro/kg, s.c.) on 4-h ethanol intake were determined. The ability of naltrexone (50 micro/kg, s.c.), an opioid antagonist, to block actions of 14-methoxymetopon (12.25, 30 micro/kg, s.c.) was examined as were the effects of 14-methoxymetopon (12.25 micro/kg, s.c.) on self-administered blood alcohol levels (BALs) and clearance of a passive ethanol bolus (1 g/kg). Finally, the effects of central 14-methoxymetopon administration (0.0003-100 ng, i.c.v.) on 4-h ethanol intake were evaluated. Systemic 14-methoxymetopon very potently and dose-dependently suppressed ethanol and food intake for 30 min, followed by a greater, longer-lasting, and behaviorally specific increase in ethanol intake. The increased ethanol intake led to threefold higher BALs, was naltrexone-reversible, and not due to altered ethanol clearance. Intracerebroventricular 14-methoxymetopon administration rapidly altered ethanol intake per an inverted U-shaped dose-response function, increasing it at a 10 pg dose, while suppressing it at a 10,000-fold higher dose. The novel mu analgesic increases ethanol intake, a potential therapeutic liability, and results suggest a non-monotonic influence of brain mu opioid receptor stimulation on ethanol intake.

Skeletal muscle and liver oxysterols during fasting and alcohol exposure

Oxysterols are cytotoxic agents that have a range of cellular actions, including impairment of albumin synthesis, cell differentiation, and induction of apoptosis. Their regulations by nutritional factors are poorly described. Our objective was to test the hypothesis that the imposition of food withdrawal and alcohol exposure increases tissue oxysterol concentrations. We measured the concentrations of the oxysterols 7 α-hydroxycholest-5-en-3 β-ol (7 α-OH), 7 β-hydroxycholest-5-en-3 β-ol (7 β-OH), and 3 β-hydroxycholest-5-en-7-one (7-keto) in liver and skeletal muscle of fed and fasted (food withdrawal for 1 and 2 days) male Wistar rats. Both oxidative (type I; soleus) and glycolytic (type II; plantaris) muscles were analyzed. We also investigated the effects of a nutritional perturbant induced by a short-term bolus of ethanol (75 mmol/kg weight IP administered 2.5 hours before sacrifice). The results showed that in response to fasting there were significant increases in 7 α-OH, 7 β-OH, and 7-keto in liver and both type I and II skeletal muscle ( P < .001 in all instances). For skeletal muscle, the increases were blunted or ameliorated after 2 days when compared with data from rats starved for 1 day. In contrast, the increases in liver after 1 day's fasting were relatively sustained at 2 days. Short-term ethanol increased 7 α-OH, 7 β-OH, and 7-keto in type I muscle of fed animals only ( P < .001 in all instances) with a significant interaction between fasting and alcohol ( P < .001 in all instances). For the first time, we have shown that oxysterols can increase in muscle and liver in response to food withdrawal and in response to an immediately imposed nutritional perturbant (ie, alcohol). Increased oxysterols represent elevated oxidative stress and/or disturbances in their formation or clearance. Because of the reported cytotoxic properties of oxysterols, these data are important in understanding cellular pathology because episodic anorexia and/or oxidative stress occur in a variety of disease conditions including sepsis, cancer cachexia, ischemia, and hormonal imbalance.

Zinc Supplementation Prevents Alcoholic Liver Injury in Mice through Attenuation of Oxidative Stress

Alcoholic liver disease is associated with zinc decrease in the liver. Therefore, we examined whether dietary zinc supplementation could provide protection from alcoholic liver injury. Metallothionein-knockout and wild-type 129/Sv mice were pair-fed an ethanol-containing liquid diet for 12 weeks, and the effects of zinc supplementation on ethanol-induced liver injury were analyzed. Zinc supplementation attenuated ethanol-induced hepatic zinc depletion and liver injury as measured by histopathological and ultrastructural changes, serum alanine transferase activity, and hepatic tumor necrosis factor-alpha in both metallothionein-knockout and wild-type mice, indicating a metallothionein-independent zinc protection. Zinc supplementation inhibited accumulation of reactive oxygen species, as indicated by dihydroethidium fluorescence, and the consequent oxidative damage, as assessed by immunohistochemical detection of 4-hydroxynonenal and nitrotyrosine and quantitative analysis of malondialdehyde and protein carbonyl in the liver. Zinc supplementation suppressed ethanol-elevated cytochrome P450 2E1 activity but increased the activity of alcohol dehydrogenase in the liver, without affecting the rate of blood ethanol elimination. Zinc supplementation also prevented ethanol-induced decreases in glutathione concentration and glutathione peroxidase activity and increased glutathione reductase activity in the liver. In conclusion, zinc supplementation prevents alcoholic liver injury in an metallothionein-independent manner by inhibiting the generation of reactive oxygen species (P450 2E1) and enhancing the activity of antioxidant pathways.

The effects of pregnancy on ethanol clearance

We have studied the effects of pregnancy on ethanol clearance rates and on blood and urine ethanol concentrations (BECs and UECs) in adult Sprague–Dawley rats infused with ethanol intragastrically. Pregnant rats had greater ethanol clearance following an intragastric or intravenous ethanol bolus (3 or 0.75 g/kg, respectively) relative to non-pregnant rats ( p < 0.05). Pregnant rats infused with ethanol-containing diets for several days had lower ( p < 0.05) UECs than non-pregnant rats when given the same dose of ethanol. Non-pregnant rats infused ethanol-containing diets at two levels of calories (the higher caloric intake required by pregnant rats [220 kca/kg 75/d] or the normal calories required for non-pregnant rats [187 kcal/kg 75/d]) had statistically equal UECs, suggesting that increased caloric intake was not responsible for the effect of pregnancy. While the activity of hepatic alcohol dehydrogenase (ADH) did not differ with pregnancy, gastric ADH activity was increased ( p < 0.001). Furthermore, total hepatic aldehyde dehydrogenase (ALDH) and hepatic mitrochrondrial protein were increased ( p < 0.05) and hepatic CYP2E1 activity was suppressed ( p < 0.05). The results suggest that pregnancy increases ethanol elimination in pregnant rats by: 1) induction of gastric ADH; 2) elevated hepatic ALDH activity; and 3) increased mitochondrial respiration. The greater ethanol clearance results in lower tissue ethanol concentrations achieved during pregnancy for a given dose, and this may have clinical significance as a mechanism to protect the growing fetus from ethanol toxicity.

Acute ethanol binge followed by withdrawal regulates production of reactive oxygen species and cytokine-induced neutrophil chemoattractant and liver injury during reperfusion after hepatic ischemia.

This work tests the hypothesis that withdrawal from an acute ethanol binge regulates the production of reactive oxygen species (ROS) and chemokines by Kupffer cells, and as a result compromises or protects the liver from injury. Male Sprague-Dawley rats received an intravenous ethanol bolus (1.75 g/kg), followed by an intravenous infusion of 200-300 mg/kg/h for 12 h. At 12 h, ethanol infusion was stopped and replaced by saline. At 18 h, rats were subjected to 45 min of partial hepatic ischemia, followed by 0-24 h of reperfusion (I/R). At specific time points, Kupffer cells were isolated for superoxide anion assay and CINC (cytokine-induced neutrophil chemoattractant) and MIP-2 (macrophage inflammatory protein-2) production in vitro. Alanine transferase (ALT) activity, endotoxin, CINC, and MIP-2 were measured in serum samples taken at appropriate intervals. Results show that at 3 h post reperfusion, serum ALT was significantly elevated in the ethanol-treated group + I/R, compared with the saline + I/R group. ROS production by Kupffer cells at this time was also significantly increased compared with the saline + I/R group. However, ethanol withdrawal + I/R did not significantly alter CINC and MIP-2 production at 3 h of reperfusion. After 24 h, serum ALT was lower in the ethanol + I/R group than in the saline + I/R group. Superoxide anion and MIP-2 releases by Kupffer cells were not statistically significantly different between these two groups at this time. CINC production by Kupffer cells from the ethanol-treated + I/R group was significantly lower than in the saline + I/R group. Concomitantly, CINC and nuclear factor-kappaB (NF-kappaB) mRNAs and NF-kappaB translocation and binding in Kupffer cells in this treatment group were down-regulated. Moreover, the number of polymorphonuclear neutrophils (PMNs) sequestered in the liver was significantly lower in the ethanol + I/R group than in the saline-treated group. ROS and chemokine productions in sham animals with or without ethanol were lower than in the I/R group. These data suggest that acute ethanol binge followed by withdrawal may compromise the liver to injury during the early phase, whereas in the later phase it may be protective. Furthermore, these results support the notion that Kupffer cells are involved in hepatic injury in the early phase, whereas PMNs participate more actively during the later phase of reperfusion.

Acute alcohol intoxication and endotoxemia desensitize HIV-1 gp120-induced CC-chemokine production by Kupffer cells

Chemokines are involved in the inhibition of HIV-1 infection and in the pathogenesis of tissue injury in a number of conditions, including endotoxemia and alcoholic liver disease. CC chemotactic peptides (MIP-1α, MCP-1 and RANTES) are produced by a wide variety of cell types in response to immunological stimuli, bacterial endotoxin and gp120 from HIV-1 and HIV-2. This work tests the hypothesis that prior exposure to endotoxin and/or ethanol in vivo inhibits the production of CC-chemokines following a secondary challenge with HIV-1 gp120 in vitro. Male Sprague-Dawley rats received in intravenous infusion of ethanol to maintain blood ethanol level at 170 mg/dl for 3 hr. Escherichia coli LPS (1 mg/Kg) was given intravenously 5 min after the ethanol bolus was injected. Control groups received similar volumes of saline. Three hr after LPS treatment, Kupffer cells were obtained and treated with HIV-1 gp120 (5 μg/10 6 cells/24 hr). At the end of the incubation period, cells were obtained for RT-PCR analysis of CC-chemokine mRNA expression. Chemokine release in culture supernatants was measured by ELISA. Results show that in vivo ethanol was associated with downregulation of MIP-1α and MCP-1 mRNA expression and protein release in primary cultures of Kupffer cells. However, ethanol alone primed isolated Kupffer cells for enhanced RANTES mRNA and protein release in the presence or absence of HIV-1 gp120. These results demonstrate that acute ethanol intoxication and endotoxemia may selectively act as a desensitizing agent in response to a secondary challenge with bacterial or viral products.

Cross-tolerance between acute alcohol intoxication and endotoxemia.

This study tests two hypotheses: (1) prior exposure to LPS induces cross-tolerance for the hepatic effects of subsequent short-term alcohol intoxication; and (2) short-term alcohol intoxication renders the liver resistant to the effects of acute endotoxemia, resulting in reduced production of superoxide and tumor necrosis factor. In the first group of experiments, male Sprague-Dawley rats were treated intravenously with E. coli lipopolysaccharide (LPS) (0.5 mg/kg) 48 hr before they were given an intravenous bolus of ethanol (1.75 g/kg), followed by 250-300 mg/kg/hr) for 3-5 hr. Superoxide release in the perfused liver was measured after 3-hr ethanol infusion. Pretreatment with LPS attenuated ethanol-mediated superoxide anion release by the perfused liver. The stimulatory effect of phorbol myristate acetate on hepatic release of superoxide was also decreased. In the second group of experiments, rats previously treated with ethanol for 5 hr, received an intravenous injection of LPS (1 mg/kg). At 90 min after LPS, sera were collected for tumor necrosis factor alpha assay. Hepatic release of superoxide anion was determined 3 hr after LPS. Acute ethanol intoxication for 5 hr significantly reduced LPS-induced serum tumor necrosis factor activity and free radical release by the perfused liver. LPS-induced mortality was also decreased. In both groups of experiments serum corticosteroid levels were reduced during cross-tolerance. These results demonstrate that cross-tolerance develops between acute alcohol intoxication and endotoxemia manifesting in reduced hepatic production of cytotoxic cytokines and superoxide anions.

The Role of Acetaldehyde in the Pathogenesis of Acute Alcoholic Pancreatitis

Acetaldehyde (AA), the first product of ethanol metabolism, has been suggested as an important mediator in alcoholic pancreatitis, but experimental evidence has not been convincing. Prior work using the isolated perfused canine pancreas preparation has suggested that toxic oxygen metabolites generated by xanthine oxidase (XO) may mediate the early injury in pancreatitis. Xanthine oxidase is capable of oxidizing AA, and during this oxidation free radicals are released. The hypothesis that acute alcoholic pancreatitis may be initiated by AA in the presence of active XO (converted from xanthine dehydrogenase [XD]) was tested in the authors' experimental preparation by converting XD to XO by a period of ischemia, and infusing AA. Control preparations remained normal throughout the 4-hour perfusion (weight gain, 7 +/- 4 g; amylase activity, 1162 +/- 202 U/dL). One hour of ischemia or infusion of AA at 25 mg/hr or at 50 mg/hr without ischemia did not induce changes in the preparation. Acetaldehyde at 250 mg/hr induced minimal edema and weight gain (16 +/- 4 g; p less than 0.05), but not significant hyperamylasemia. Changes also were not observed when 1-hour ischemia was followed by a bolus of ethanol (1.5 g) or sodium acetate (3.0 g), or by infusion of 25 mg/hr of AA. One hour of ischemia followed by infusion of AA at 50 mg/hr or at 250 mg/hr induced edema, hemorrhage, weight gain (22 +/- 7 g [p less than 0.05] and 26 +/- 17 g [p less than 0.05]) and hyperamylasemia (2249 +/- 1034 U/dL [p less than 0.05] and 2602 +/- 1412 U/dL [p less than 0.05]). Moreover infusion of AA at 250 mg/hr after 2 hours of ischemia potentiated the weight gain (62 +/- 20 g versus 30 +/- 14 g [p less than 0.05]), but not the hyperamylasemia (3404 +/- 589 U/dL versus 2862 +/- 1525 U/dL) as compared with 2 hours of ischemia alone. Pancreatitis induced by 1 hour of ischemia followed by AA at 50 mg/hr could be inhibited by pretreatment with the free radical scavengers superoxide dismutase and catalase and ameliorated with the XO inhibitor allopurinol. The authors conclude that AA, in the presence of active XO, can initiate acute pancreatitis in the isolated canine pancreas preparation and may be important in the initiation of acute alcoholic pancreatitis in man. Toxic oxygen metabolites appear to play an important intermediary role.

Effect of Dihydrotestosterone on the Rate of Ethanol Elimination in Healthy Men

Testosterone (T) and, more potently, dihydrotestosterone (DHT), are in vitro inhibitors of hepatic alcohol dehydrogenase (ADH). An increase in the rate of ethanol disappearance (RED) in man has been observed after orchidectomy. We thus investigated the influence of DHT administration on RED in 10 healthy male volunteers. RED was estimated after an oral ethanol bolus (0.6 g/kg), before and after a 14-day treatment with DHT (2 x 125 mg per day percutaneously; Andractim, Besins iscovesco, France). A mean 11.5-fold increase in DHT levels and a 2.0-fold decrease in T values were observed after DHT administration, confirming the good compliance with treatment. RED was decreased after DHT (0.168 +/- 0.043 vs. 0.137 +/- 0.043 g/l/hr; mean +/- SD; p less than 0.01 using Wilcoxon's paired comparison test). These data are consistent with a DHT-induced inhibition of hepatic ADH in vivo. This could have a beneficial effect by decreasing acetaldehyde production in alcoholic patients, in whom marked hypoandrogenism frequently occurs.

Cardiorespiratory reflex effects induced by intravenous administration of ethanol in rats

Intravenous administration of a bolus of ethanol (40 mg/100 g b.w.) to rats induced bradycardia, hypotension and apnea. Bradycardia was dose dependent (r=−0.78, p<0.001). Acute bilateral vagotomy blocked bradycardia and hypotension. Apnea, however, persisted in all cases but was of short duration and occurred after a significant delay as compared to an untreated group. Atropine (0.1 mg/100 g b.w.) and hexamethonium (0.75 mg/100 g b.w.) blocked bradycardia and early hypotension. Pretreatment with reserpine (0.25 mg/100 g b.w. IP 24 and 48 hours before the experiment) significantly increased bradycardia induced by ethanol as compared to untreated animals. In rats pretreated with reserpine and vagotomized, IV ethanol did not induce bradycardia, early hypotension or apnea. A bolus of ethanol (20 mg/100 g b.w.) given directly into the left ventricle did not induce reflex changes in heart rate or respiration, while the same dose of alcohol given IV decreased heart rate by 53±8.9%. Thus, the ethanol effect seems to be initiated in pulmonary J receptors. Bradycardia appeared to be mediated both by increase in vagal tone, and to a lesser extent, by sympathetic withdrawal. Hypotension was due mainly to bradycardia, and apnea might be caused by a dual mechanism, reflex (early) and direct on the respiratory center (late).