Effect Of Ethanol Ingestion Research Articles

Low ethanol consumption induces enhancement of insulin sensitivity in liver of normal rats

Moderate amounts of alcohol intake have been reported to have a protective effect on the cardiovascular system and this may involve enhanced insulin sensitivity. We established an animal model of increased insulin sensitivity by low ethanol consumption and here we investigated metabolic parameters and molecular mechanisms potentially involved in this phenomenon. For that, Wistar rats have received drinking water either without (control) or with 3% ethanol for four weeks. The effect of ethanol intake on insulin sensitivity was analyzed by insulin resistance index (HOMA-IR), intravenous insulin tolerance test (IVITT) and lipid profile. The role of liver was investigated by the analysis of insulin signaling pathway, GLUT2 gene expression and tissue glycogen content. Rats consuming 3% ethanol showed lower values of HOMA-IR and plasma free fatty acids (FFA) levels and higher hepatic glycogen content and glucose disappearance constant during the IVITT. Neither the phosphorylation of insulin receptor (IR) and insulin receptor substrate-1 (IRS-1), nor its association with phosphatidylinositol-3-kinase (PI3-kinase), was affected by ethanol. However, ethanol consumption enhanced liver IRS-2 and protein kinase B (Akt) phosphorylation (3 times, P < 0.05), which can be involved in the 2-fold increased ( P < 0.05) hepatic glycogen content. The GLUT2 protein content was unchanged. Our findings point out that liver plays a role in enhanced insulin sensitivity induced by low ethanol consumption.

Antecedent Ethanol Ingestion Prevents Postischemic Leukocyte Adhesion and P-Selectin Expression by a Protein Kinase C?Dependent Mechanism

The aim of this study was to determine whether protein kinase C (PKC) contributed to the effects of ethanol ingestion to prevent P-selectin expression, leukocyte rolling (LR), and stationary leukocyte adhesion (LA) induced by subjecting the small bowel to ischemia and reperfusion (I/R) 24 hr later. I/R increased P-selectin expression, LR, and LA, effects that were largely abolished by antecedent ethanol consumption. Exposing the bowel to a specific but nonisoform-selective PKC inhibitor (chelerythrine or bisindolylmaleimide I) during the period of ethanol exposure did not alter the anti-inflammatory effects induced by ethanol ingestion 24 hr prior to I/R. Go-6976, a PKC inhibitor that exhibits a high degree of selectivity for the calcium-dependent PKC isoforms, markedly reduced the effectiveness of antecedent ethanol exposure to abrogate these postischemic inflammatory responses. Our data indicate that antecedent ethanol exposure prevents postischemic P-selectin expression, LR, and LA by a mechanism that involves activation of calcium-dependent PKC isotypes.

Effects of ethanol intake and ethanol withdrawal on free-running circadian activity rhythms in rats

Chronic alcohol intake and alcohol withdrawal are associated with dramatic disruptions of daily (circadian) biological rhythms in both human alcoholics and experimental animals. The extent to which these observations are due to pharmacological effects on the underlying circadian pacemaker is not known, however, since no human studies and very few animal studies have been conducted under free-running conditions. In the present study, free-running circadian activity (wheel-running) rhythms of rats were monitored before, during and after exposure to either 10% or 20% ethanol solution as the only drinking fluid. Across individuals, both lengthening and shortening of free-running period were observed during ethanol intake, and treatment termination led to either a return to baseline or to an exacerbation of the original ethanol effect. These variable effects appeared to be related to both ethanol concentration and to individual differences in baseline period, such that relatively short free-running period during baseline was associated with greater period-lengthening during ethanol exposure. These bidirectional affects of ethanol on free-running period are generally similar to effects seen previously with other psychoactive drugs, including antidepressants. The results of this study indicate that ethanol influences the circadian pacemaker, and that the chronobiological disruptions seen in human alcoholics may be due, in part, to alterations in circadian pacemaker regulation.

Ethanol intake inhibits growth of the epithelium in the intestine of pregnant rats

The effects of ethanol ingestion on jejunal and ileal epithelial cells were studied in pregnant rats by measuring crypt and villus cell population, crypt cell proliferation, and crypt cell cycle time as parameters. Timed-pregnancy female rats were fed a liquid diet containing either ethanol [designated as ethanol-fed group (EFG)] or an isocaloric amount of carbohydrate [designated as pair-fed group (PFG)] from gestational day 2 up to delivery. Daily diet ingestion, body weight, nitrogen balance, and nitrogen digestibility were assessed during the gestational period. Crypt and villus cell population, crypt cell proliferation, and crypt cell cycle time were measured in the maternal small intestine at the time animals were killed, just after delivery. Ethanol consumption resulted in ileal hypoplasia of the crypt and villus, but only the villus showed hypoplasia in the jejunum. In addition, crypt cell proliferation was markedly decreased, whereas crypt cell cycle time was longer, both in the jejunum and ileum of the EFG. Ethanol ingestion had no significant effect on body weight gain, nitrogen balance, and nitrogen digestibility. According to our expectations, the offspring from the EFG had significantly lower body weight. In conclusion, chronic ethanol ingestion during pregnancy inhibited the maternal intestinal epithelium growth, more extensively in the ileum.

Effect of prenatal exposure to ethanol on hepatic elongation factor-2 and proteome in 21 d old rats: protective effect of folic acid.

In this article, we study the effects of ethanol intake during pregnancy and lactation on hepatic and pancreatic elongation factor-2 (EF-2) of 21 d old progeny. At the same time, the effect of ethanol on the level of other relevant hepatic proteins was determined using proteomic analysis. The results show that ethanol not only produces a general increase of protein oxidation, but also produces an important depletion of EF-2 and several other proteins. Among the hepatic proteins affected by ethanol, the concomitant supplementation with folic acid to alcoholic mother rats prevented EF-2, RhoGDI-1, ER-60 protease, and gelsolin depletion. This protective effect of folic acid may be related to its antioxidant properties and suggests that this vitamin may be useful in minimizing the effect of ethanol in the uterus and lactation exposure of the progeny.

Effect of Ethanol Intake During Lactation on Male and Female Pups' Liver and Brain Metabolism During the Suckling-Weaning Transition Period

In rats, a high degree of brain development and myelination occurs during the first 15 days after birth. Ethanol intake by lactating rats modified 12 day-old pups' brain development and metabolism. The aim of the present study was to evaluate the effect of maternal ethanol ingestion during lactation on prepubertal (24-day-old) pups' brain and liver metabolism.Lactating rats (4 male and 4 female litters) were divided into 2 groups: control--received control liquid diet, and ethanol--received liquid diet containing 4% of ethanol. On postnatal day 24, the pups were killed by decapitation. Liver and brain were utilized for measuring Adenosine Tri-phosphate-citrate lyase and malic enzymes activities. Brain slices were incubated in medium containing glucose to determine glucose consumption and oxidation, and lipid synthesis.The ethanol intake decreased male and female pups' body, brain and liver weight. Liver Adenosine Tri-phosphate-citrate lyase activity was decreased only in male pups of the ethanol group. The intake of ethanol solution by the dams increased glucose consumption and oxidation by the incubated female pups' brain slices and decreased glucose oxidation by the male pups' brain slices. It can be concluded that the effects of maternal ethanol intake on pups' development and metabolism are gender-related.

Neuromodulatory role of the endocannabinoid signaling system in alcoholism: an overview

The current review evaluates the evidence that some of the pharmacological and behavioral effects of ethanol (EtOH), including EtOH-preferring behavior, may be mediated through the endocannabinoid signaling system. The recent advances in the understanding of the neurobiological basis of alcoholism suggest that the pharmacological and behavioral effects of EtOH are mediated through its action on neuronal signal transduction pathways and ligand-gated ion channels, receptor systems, and receptors that are coupled to G-proteins. The identification of a G-protein-coupled receptor, namely, the cannabinoid receptor (CB1 receptor) that was activated by Δ9-tetrahydrocannabinol (Δ9-THC), the major psychoactive component of marijuana, led to the discovery of endogenous cannabinoid agonists. To date, two fatty acid derivatives identified to be arachidonylethanolamide (AEA) and 2-arachidonylglycerol (2-AG) have been isolated from both nervous and peripheral tissues. Both these compounds have been shown to mimic the pharmacological and behavioral effects of Δ9-THC. The involvement of the endocannabinoid signaling system in the development of tolerance to the drugs of abuse including EtOH has not been known until recently. Recent studies from our laboratory have demonstrated for the first time the down-regulation of CB1 receptor function and its signal transduction by chronic EtOH. The observed down-regulation of CB1 receptor binding and its signal transduction results from the persistent stimulation of the receptors by the endogenous CB1 receptor agonists, AEA and 2-AG, the synthesis of which has been found to be increased by chronic EtOH treatment. This enhanced formation of endocannabinoids may subsequently influence the release of neurotransmitters. It was found that the DBA/2 mice, known to avoid EtOH intake, have significantly reduced brain-CB1-receptor function consistent with other studies, where the CB1 receptor antagonist SR141716A has been shown to block voluntary EtOH intake in rodents. Similarly, activation of the CB1 receptor system promoted alcohol craving, suggesting a role for the CB1 receptor gene in excessive EtOH drinking behavior and development of alcoholism. Ongoing investigations may lead to the development of potential therapeutic strategies for the treatment of alcoholism.

Effects of chronic ethanol ingestion on nutritional status in three successive generations of rats

The purpose of this study was to determine the effects of chronic ethanol ingestion on the nutritional status of three successive generations of rats. Ethanol treated rats received ad libitum 5, 10 and 15% ethanol in their drinking fluid over 3 successive weeks. Then, a concentration of 20% was maintained for 5 additional weeks and until the end of the experimental period. Males and females in the ethanol treated group were mated to obtain the 1st generation offspring. Subsequently, females and males from the 1st generation offspring were mated to obtain the 2nd generation offspring. Finally, males and females of the 2nd generation offspring were mated to obtain the 3rd generation offspring of ethanol treated rats. Another group served as control and received only water, a standard rat chow diet, and was handled in the same way as the other experimental groups. The results indicated that the body weight of (21-days post-natal) ethanol treated rats was significantly lower than that of the control group. Intestinal length/body weight ratios of (6-months post-natal) ethanol treated rats, were significantly greater in the 1st and 2nd generation, but the 3rd generation ethanol treated rats tended to attain weights and ratios comparable to controls. In both the 1st and 2nd generation offspring, the mean total calorie consumption was not different from that of the control group, but the proportion of calories from chow was reduced. Conversely, the 3rd generation offspring consumed more calories. Furthermore, the body weight at the end of the experimental period in the 1st and 2nd generation offspring was lower than the control group, but the body weight of the 3rd generation was not different in the two groups. In conclusion these results indicate a possible effect of ethanol ingestion on the nutritional status of 1st and 2nd generation offspring.

Role of Kupffer cells and gut-derived endotoxins in alcoholic liver injury.

The hepatotoxic effects of alcohol have been described in detail, but factors responsible for its hepatotoxicity have only partially been characterized. For example, it is known that chronic ethanol ingestion increases hepatotoxicity and produces fatty liver, hepatitis and cirrhosis. However, acute ethanol consumption reduces endotoxin hepatotoxicity. It now appears that Kupffer cells participate in several aspects of these phenomena. Previously, most studies on the effects of alcohol on liver function have focused chiefly on the hepatocyte. Recently, attention has been directed towards the effect of ethanol ingestion on Kupffer cell function, which is stimulated by gut-derived endotoxins (lipopolysaccharides) via mechanisms dependent on increased gut permeability and the possible relationship between Kupffer cells and alcohol-induced liver injury. Here we will review new evidence for the proposal that Kupffer cells and endotoxins play a pivotal role in hepatotoxicity following alcohol exposure, based on studies using the continuous intragastric enteral feeding model developed by Tsukamoto and French and an acute model developed by us.

Ethanol ingestion combined with lowered carbohydrate (sucrose) intake aggravates diabetes mellitus in spontaneously diabetic rats

The effects of ethanol ingestion on the development of diabetes mellitus were studied in relation to simultaneous carbohydrate intake. We used sucrose as a carbohydrate source. Two groups of spontaneously diabetic (non-insulin dependent type) male rats (Otsuka Long-Evans Tokushima Fatty Strain, OLETF) at 10 weeks of age were fed liquid diets containing ethanol (4.0 g/day) with different amounts of sucrose (6.8 or 13.8 g/day) in 100 ml solution for 20 weeks. Two other groups of the same strain were studied. One was kept to be fed a liquid diet containing sucrose (13.8 g/day) without ethanol in 100 ml solution and the other was given free access to solid chow and water and served as a control group. Each of the four groups had 10 rats. The three liquid diets were the same except for ethanol and sucrose content and contained adequate amounts of protein, fat, vitamins and minerals. Shortly after the start of experimental feeding (12 weeks of age), an oral glucose tolerance test (OGTT) showed no abnormalities in any groups. However, at the end of the experiment (30 weeks of age), almost all the rats were diabetic. The severity of diabetes mellitus was ranked by the area under the plasma glucose concentration-time curves during OGTT, as follows: rats fed ethanol with low-sucrose diet (EL) > rats fed ethanol with high-sucrose diet (EH) > rats fed control liquid diet (CL) ≒ rats fed solid chow (CS). Despite the marked difference in plasma glucose levels, there was no significant difference in plasma insulin levels during OGTT among the groups. Body weight rank was EH > CL ≒ CS > EL. No differences were observed in plasma triacylglycerol and total cholesterol levels among the four groups throughout the experimental period. These findings suggest that ethanol ingestion combined with lowered sucrose intake aggravates diabetes mellitus in genetically diabetic rats.

Effect of Chronic Ethanol Consumption on Fatty Acid Profile of Heart Tissue in Rats

The effect of chronic ethanol ingestion on fatty acid composition and lipid content of heart tissue in rats, and whether this effect depends on age, was studied. Rats were maintained on a 30% ethanol solution in drinking water for 3 and 5 months. Control animals were given water. Phospholipid concentration was unchanged in the ethanol-fed groups, compared with control groups, whereas total cholesterol content was increased at 5 months of treatment. An increase in stearic acid, palmitoleic acid, and 22:5n6 were observed at 3 months of ethanol ingestion. When ethanol was administered for 5 months, polyunsaturated fatty acids series n3 were decreased with respect to control. The effect of age on the profile of fatty acids of heart showed an increase of monounsaturated fatty acids and a decrease of long-chain polyunsaturated fatty acids in both control and ethanol-fed rats. The effect of ethanol ingestion on fatty acid composition of heart tissue is not very pronounced, but the small changes observed could contribute to the development of functional and electrophysiological features of alcoholic heart disease.

Effect of Chronic Ethanol Consumption on Fatty Acid Profile of Heart Tissue in Rats

The effect of chronic ethanol ingestion on fatty acid composition and lipid content of heart tissue in rats, and whether this effect depends on age, was studied. Rats were maintained on a 30% ethanol solution in drinking water for 3 and 5 months. Control animals were given water. Phospholipid concentration was unchanged in the ethanol-fed groups, compared with control groups, whereas total cholesterol content was increased at 5 months of treatment. An increase in stearic acid, palmitoleic acid, and 22:5n6 were observed at 3 months of ethanol ingestion. When ethanol was administered for 5 months, polyunsaturated fatty acids series n3 were decreased with respect to control. The effect of age on the profile of fatty acids of heart showed an increase of monounsaturated fatty acids and a decrease of long-chain polyunsaturated fatty acids in both control and ethanol-fed rats. The effect of ethanol ingestion on fatty acid composition of heart tissue is not very pronounced, but the small changes observed could contribute to the development of functional and electrophysiological features of alcoholic heart disease.

Effects of ethanol ingestion on sperm monosaccharides and fertility.

Chronic alcohol abuse is often associated with reproductive disorders. Sperm monosaccharides play an indispensable role in sperm-egg interactions and fertilization. Ethanol (3 g/kg body weight as 25%, v/v) was given by gastric intubation twice daily for 30 days while in another group, rats which had been treated with ethanol were withdrawn from treatment for a further period of 30 days, in order to assess the reversibility of the ethanol-induced effects. Epididymal ethanol content, sperm monosaccharides and the fertility of ethanol treated and ethanol withdrawn rats were assessed. Ethanol ingestion caused a significant decrease in sperm monosaccharides suggesting defective glycosylation of sperm surface proteins. Sperm monosaccharides and fertility were returned to normal following the withdrawal of ethanol. Ethanol-induced changes in sperm monosaccharides may be one of the reasons for the reduced fertility of ethanol treated rats.

Effects of ethanol ingestion on epididymal glycosidases and fertility in the rat.

Epididymal glycosidases play a role in sperm maturation by modifying sperm surface glycoproteins. To study the effects of ethanol on epididymal sperm maturation, ethanol (3 g/kg body weight as 25%, v/v) was administered to a group of rats by gastric-intubation twice daily for 30 days. In another group, rats were also treated with alcohol for 30 days but were then withdrawn from treatment for 30 days to assess the reversibility of ethanol-induced effects. Ethanol-induced changes in epididymal tissue and sperm glycosidases, cauda epididymal sperm motility and the fertility of rats were assessed. Ethanol treatment caused a marked decrease in the specific activities of glycosidases in both tissues and spermatozoa from epididymal segments. Cauda epididymal sperm motility and the fertility of ethanol-treated rats were significantly impaired compared to control rats fed an isocaloric diet. These changes are likely to be the consequence of direct and indirect effects of ethanol mediated through subnormal testosterone and dihydrotestosterone. Most of these changes were found to be reversible. The present study suggests that impaired activity of sperm glycosidases may be one of the factors responsible for defective sperm motility and fertilizing potential in ethanol-treated rats.

Effects of ethanol intake on retinol concentration in the milk of lactating rats.

The effect of the consumption of ethanol (5%) on retinol concentration in milk was studied in the rat on day 12 after delivery, together with the evolution of dam body weight and pup growth rate. Female Wistar rats receiving alcohol (5%) in drinking water during lactation (N = 7) were compared to normal controls fed ad libitum (N = 6). The mean maternal alcohol intake was 3.96 +/- 0.23 g/kg body weight per day. To determine retinol levels in milk we used the Bessey and Lowry method, modified by Araújo and Flores ((1978) Clinical Chemistry, 24:386-392). The pups were separated from dams for a 2-4-h period, after which the dams were injected intraperitoneally with anesthetic and oxytocin. The concentration of retinol in milk was 162.88 +/- 10.60 micrograms/dl in the control group and 60.02 +/- 8.22 micrograms/dl in the ethanol group (P < 0.05). The ethanol group consumed less food than the controls and lost a significant amount of weight during lactation. On days 8, 10 and 12, the body weight of the pups from rats given ethanol (13.46 +/- 0.43, 16.12 +/- 0.48 and 18.60 +/- 0.91 g, respectively) were significantly lower (P < 0.05) than the weight of pups from controls (15.2 +/- 0.44, 18.36 +/- 0.54, 20.77 +/- 0.81 g). These data show that ethanol intake during the suckling period, even at low concentrations, decreases the amount of retinol in milk and, therefore, the amount available to the pups.

Effects of ethanol ingestion on insulin binding to rat Leydig cells.

Effects of ethanol treatment and its withdrawal on insulin binding to isolated rat Leydig cells were studied. Mature rats were given ethanol by gastric intubation for 30 days at a dose of 3.0 g/kg body weight, twice daily, as a 25% (v/v) aqueous solution and treatment was withdrawn for the subsequent 30 days in an another group. Ethanol treatment markedly increased serum insulin and reduced the 125I-insulin binding to Leydig cells and the activities of Leydig cellular steroidogenic enzymes such as 3 beta-HSD and 17 beta-HSD. Withdrawal of ethanol treatment restored these changed values to their normal levels. The results suggest the possible involvement of subnormal insulin actions, as that of LH, in the ethanol-induced impairment of Leydig cellular steroidogenesis and the resulting hypoandrogenization associated with alcohol abuse.

Ethanol Consumption Suppresses Cell‐Mediated Inflammatory Responses and Increases T‐Helper Type 2 Cytokine Secretion in Trichinella spiralis‐Infected Rats

Alcohol consumption has been shown to be associated with immune suppression and immune modulation. In this study, the effects of ethanol ingestion on the host immune responses to Trichinella spiralis infection and the subsequent secretion of T-helper cell-associated cytokines were investigated in rats. At the early phase of T. spiralis infection, ethanol-fed animals showed decreased numbers of blood neutrophils and eosinophils, and a decreased secretion of interferon-gamma (IFN-gamma) by mesenteric lymph node cells, compared with pair-fed controls. Suppression of this early inflammatory response to infection in the ethanol-treated groups resulted in a slower rate of expulsion of intestinal adult worms and a higher fecundity rate for female worms, compared with pair-fed controls. A dramatic decrease in blood neutrophils in the ethanol-treated groups was also manifested on day 9 postinfection. At that time, mesenteric lymph node cells from the ethanol-treated groups secreted higher amounts of mast cell proliferation-enhancing activity, which has been shown to contain T-helper type 2-associated cytokines. At the later phase of infection (day 12 to 20 day postinfection), ethanol-treated animals contained higher numbers of blood eosinophils and secreted an increased amount of interleukin-5 and mast cell proliferation-enhancing activity, compared with pair-fed controls. Although there was a slight rise with time after infection, the level of serum corticosterone was not significantly increased in the ethanol groups. Therefore, it is not likely that the observed immune modulations caused by ethanol consumption, especially in the early phase of infection, is the effect of elevated levels of corticosterone in the circulation. The present study found that ethanol consumption suppressed the initial amount of interferon-gamma secretion and inflammatory response, and may have directly or indirectly led to an enhancement of the secretion of T-helper type 2-type cytokines later in the primary immune response to T. spiralis infection.

Ethanol Consumption Suppresses Cell-Mediated Inflammatory Responses and Increases T-Helper Type 2 Cytokine Secretion in Trichinella spiralis-Infected Rats

Alcohol consumption has been shown to be associated with immune suppression and immune modulation. In this study, the effects of ethanol ingestion on the host immune responses to Trichinella spiralis infection and the subsequent secretion of T-helper cell-associated cytokines were investigated in rats. At the early phase of T. spiralis infection, ethanol-fed animals showed decreased numbers of blood neutrophils and eosinophils, and a decreased secretion of interferon-γ (IFN-γ) by mesenteric lymph node cells, compared with pair-fed controls. Suppression of this early inflammatory response to infection in the ethanol-treated groups resulted in a slower rate of expulsion of intestinal adult worms and a higher fecundity rate for female worms, compared with pair-fed controls. A dramatic decrease in blood neutrophils in the ethanol-treated groups was also manifested on day 9 postinfection. At that time, mesenteric lymph node cells from the ethanol-treated groups secreted higher amounts of mast cell proliferation-enhancing activity, which has been shown to contain T-helper type 2-associated cytokines. At the later phase of infection (day 12 to 20 day postinfection), ethanol-treated animals contained higher numbers of blood eosinophils and secreted an increased amount of interleukin-5 and mast cell proliferation-enhancing activity, compared with pair-fed controls. Although there was a slight rise with time after infection, the level of serum corticosterone was not significantly increased in the ethanol groups. Therefore, it is not likely that the observed immune modulations caused by ethanol consumption, especially in the early phase of infection, is the effect of elevated levels of corticosterone in the circulation. The present study found that ethanol consumption suppressed the initial amount of interferon-γ secretion and inflammatory response, and may have directly or indirectly led to an enhancement of the secretion of T-helper type 2-type cytokines later in the primary immune response to T. spiralis infection.

Effects of 5-HT3 receptor agonists on voluntary ethanol intake in rats maintained on a limited access procedure.

Recent evidence from a variety of laboratory studies suggests that the central effects of ethanol (EtOH) are mediated by serotonin 5-HT3 receptors. Notably, EtOH is able to potentiate 5-HT action on 5-HT3 ionophore, and 5-HT3 antagonists are known to reduce certain effects of EtOH. In the present study, we evaluated the effects of two agonists of 5-HT3 receptors, 2-methyl-5-HT (2-Me-5-HT) and m-chlorophenylbiguanide (m-CPBG) that were microinjected i.c.v. and into the nucleus accumbens (NAC) on EtOH intake in Wistar rats with high EtOH preference. 2-Me-5-HT given i.c.v. (1 and 10 microg per rat) and into the NAC (bilaterally 1 and 10 microg per site) significantly reduced EtOH intake in the limited access paradigm (2h session). On the other hand m-CPBG was inactive after intra-NAC administration. It is concluded that central 5-HT3 receptors are involved in the regulation of EtOH consumption.

Decreased natural killer cytotoxic activity in chronic alcoholism is associated with alcohol liver disease but not active ethanol consumption.

Chronic alcohol intake is associated with an increased incidence of certain neoplasms. Natural killer (NK) cells have been considered to be involved in control tumor development and growth. The goal of the present study was to contribute to a better understanding of the effects of ethanol (EtOH) per se on the NK-cell population. Both patients with chronic alcoholism without liver disease (AWLD) and subjects with alcohol-induced cirrhosis (ALC) were carefully selected for this study. Immunophenotypical and functional studies of peripheral blood (PB) NK-cells were performed during active EtOH intake and after 3 months of a withdrawal period. In the AWLD group a significant increase in number of NK-cells (CD3-/CD56+) (P < .05) associated with a parallel increase in NK-cell lytic activity (P < .01) was observed. In addition, the number of cytotoxic T cells displaying the CD3+/CD56+ phenotype as well as CD8-/CD57+ NK-cell subset was also increased (P < .01 and P < .001, respectively). By contrast, in ALC patients with active EtOH intake (ALCET group), although a significant increase in the number of NK PB lymphocytes was observed (P < .05), NK lytic activity was depressed (P < .05), suggesting the existence of a decreased lytic activity/NK-cell. After 3 months of EtOH withdrawal, PB mononuclear cells (PBMC) from the AWLD group patients still displayed an increased NK cytolytic activity; in addition, the number of PB NK-cells (CD3-/CD56+ and CD8-/CD57+) and CD3+/CD56+ PB T cells continued to be increased. Independently of the duration of withdrawal period, in ALC patients EtOH withdrawal was followed by a slight decrease in the NK lytic activity of PBMC with respect to the values in active alcoholism phase; slight differences observed in the NK lytic activity in ALC patients who quit drinking could be related to the tendency to decrease of the number of NK-cells toward normal values. Furthermore, although an increase in NK cytotoxic activity after stimulation of PBMC with interleukin-2 (IL-2) was observed in ALC, it did not reach the levels observed in healthy subjects. Overall, our results show that the behavior of PB NK-cell population in chronic alcoholism is different according to both the moment of EtOH consumption and the existence or not of ALC. Alcohol by itself induced an increase in the number and lytic activity of NK-cells. By contrast, the NK cytolytic activity is constantly depressed in the stage of alcoholic cirrhosis, supporting the notion that immunosurveillance mechanisms may be affected in these patients.