Effects Of Chronic Ethanol Consumption Research Articles

Effect of chronic ethanol consumption on the expression of complement components and acute-phase proteins in liver

The complement system can provoke but also participate in the repair of liver injury. Here we investigated by microarray analysis the effect of chronic ethanol consumption on hepatic mRNA expression of complement components and acute-phase proteins in complement C3-deficient ( C3 −/−) and wild-type ( C3 +/+) mice. Up-regulation by ethanol of factor B, C1qA-chain and clusterin but down-regulation of factor H, Masp-2, factor D and the terminal components C6, C8α and C9 was seen in both strains. Ethanol up-regulated C2 and down-regulated C4bp only in C3 +/+ mice, while in C3 − /− mice up-regulation of C1qB-chain and vitronectin was observed. The expression of factor B, C6, C1qB and factor I was lower but that of factor D higher in C3 − /− than in C3 +/+ mice. Ethanol induced mRNA synthesis of many acute-phase proteins including SPARC and lipocalin-2, but reduced the expression of SAP. The induction of early classical and alternative pathway components and suppression of terminal pathway components and soluble regulators may thus contribute to alcohol-induced liver injury. Lipocalin-2 and SPARC emerge as new candidate markers for early detection of liver damage.

Ethanol consumption alters expression and colocalization of bile salt export pump and multidrug resistance protein 2 in the rat

Chronic ethanol consumption elicits detrimental changes of liver metabolism. By employing a 12-week-long feeding regimen, we investigated the effects of chronic ethanol consumption on the expression and localization of bile salt export pump (Bsep), a major canalicular exporter of bile salts, and multidrug resistance protein 2 (Mrp2), a canalicular organic anion transporter, in the rat liver. RT-PCR, confocal immunofluorescence microscopy, immunoblotting, and quantitative colocalization analysis were used to examine their gene and protein expression, and changes in the distribution of antigenic sites. Bsep mRNA was upregulated, while Mrp2 mRNA responded by downregulation. In agreement with mRNA, the expression of Bsep protein increased, while the expression of Mrp2 protein responded with a decrease, suggesting that the expression of both of them is transcriptionally regulated. Confocal immunofluorescence microscopy showed disruption of the colocalization of Bsep and Mrp2 proteins at the hepatocyte canalicular membrane and their relocation intracellularly. Quantitative colocalization analysis of Bsep and Mrp2 proteins revealed a steady decrease in the degree of colocalization and Mrp2 expression, indicating that although the properties of both transporters are affected, Mrp2 is altered more. These findings provide evidence that ethanol alters Bsep and Mrp2 canalicular transporters in the rat liver, at both the mRNA and protein levels. Mrp2 shows deeper involvement. Eight weeks appears to be a critical time point in this process.

Effect of chronic ethanol consumption on endothelin-1 generation and conversion of exogenous big-endothelin-1 by the rat carotid artery

The purpose of the present work was to investigate whether conversion of exogenous applied big-endothelin-1 (Big-ET-1) as well as the basal release and mRNA levels of endothelin-1 (ET-1) is altered by ethanol consumption in the rat carotid. The measurement of the contraction induced by Big-ET-1 served as an indicative of functional endothelin (ET)-converting enzyme (ECE) activity. Cumulative application of exogenous Big-ET-1 elicited a concentration-related contraction with the concentration–response curve shifted to the right when compared to ET-1. In endothelium-intact rings, phosphoramidon (1 mmol/l), a nonselective ECE/neutral endopeptidase (NEP) inhibitor, produced a rightward displacement of the concentration–response curves and reduced the maximal contractile response to Big-ET-1. However, in endothelium-denuded rings phosphoramidon reduced the maximum contraction for Big-ET-1 but did not alter the potency when compared to the curves obtained in the absence of the inhibitor. Ethanol consumption for 2, 6, or 10 weeks reduced the contractile effect elicited by Big-ET-1 in carotid rings with intact endothelium when compared to control or isocaloric rings. However, no differences on Big-ET-1–induced contraction were observed after endothelial denudation. On the other hand, ethanol consumption increased ET-1–induced contraction. Finally, chronic ethanol consumption did not alter either the mRNA levels for pre–pro-ET-1 nor the basal release of ET-1. The present findings show that chronic ethanol consumption does not alter the mRNA levels for ET-1 or its basal release in the rat carotid. Moreover, ethanol intake reduces the contraction induced by exogenously applied Big-ET-1 in carotid rings with intact endothelium, a fact that might be the result of a reduced conversion of this peptide by ECE on its mature active peptide ET-1.

Altered activity of cytochrome P450 in alcoholic fatty liver exposed to ischemia/reperfusion

Ischemia/reperfusion (I/R) injury is a major cause of morbidity and mortality in liver surgery and transplantation, and fatty livers are susceptible to greater I/R injury and a higher incidence of primary graft nonfunction after transplantation. Because alcohol intake and obesity are major causes of fatty liver, this study was initiated to investigate the effect of chronic ethanol consumption on hepatic microsomal cytochrome P450 (CYP) activity after I/R. Rats were fed an alcohol liquid diet or a control isocaloric diet for 4 weeks, and then subjected to 60 min of hepatic ischemia and 5 h of reperfusion. It was found that, chronic ethanol consumption significantly increased liver weight, serum triglyceride (TG), liver TG, and serum aminotransferase activities. Moreover, alcoholic fatty livers exposed to I/R showed significantly higher levels of aminotransferase activities than the controls. No significant differences in microsomal CYP content or CYP1A1 activity were found between I/R treated animals fed a control diet (the CD + I/R group) and I/R treated animals fed an ethanol containing diet (the ED + I/R group). Moreover, whereas CYP1A2 activity was decreased in the ED + I/R group versus the CD + I/R group, CYP2E1 activity was elevated. Additionally, chronic alcohol consumption up-regulated TNF-alpha and IL-6 mRNA levels immediately after I/R. In conclusion, chronic ethanol consumption was found to potentiate hepatocellular damage as indicated by abnormalities in microsomal drug metabolizing function during I/R.

Effect of Chronic Ethanol Consumption on the Response of Parathyroid Hormone to Hypocalcemia in the Pregnant Rat

Chronic alcohol (ethanol) consumption during pregnancy results in maternal/fetal hypocalcemia, which may underlie some of ethanol's adverse effects on maternal and fetal bone, and fetal/neonatal health. Ethanol appears to alter the relationship between parathyroid hormone (PTH) and blood calcium (Ca) level, and PTH does not increase in response to ethanol-induced hypocalcemia. However, it is not known whether ethanol actually prevents PTH from responding, or whether the ability to regulate blood Ca is intact, but ethanol lowers the level of Ca maintained. The objective of this study was to determine whether chronic ethanol consumption impairs the ability of the pregnant female to increase PTH in response to acute hypocalcemia. Rats were fed isocaloric diets with ethanol (36% ethanol-derived calories, E group) or without ethanol [pair-fed (PF) and control (C) groups], before and throughout 21 days of gestation. On day 21 gestation, rats received an intraperitoneal injection of ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) (300 or 500 mumol/kg body weight) or saline (saline group), or no injection (baseline group). Blood was collected from the baseline group, and at 30 or 60 minutes postinjection (saline and EGTA groups), and analyzed for ionized Ca (iCa), pH, and PTH. Consistent with previous studies, ethanol consumption decreased blood iCa levels at baseline, but PTH levels did not differ among groups. Administration of EGTA significantly decreased blood iCa levels by 30 minutes, but ethanol did not prevent PTH from increasing in response to the hypocalcemia. In all diet groups, PTH levels were significantly increased by 30 minutes. Ethanol did, however, appear to decrease the maximum PTH level achievable in blood. These data suggest that chronic ethanol consumption does not impair the ability of the pregnant rat to raise serum PTH levels in response to acute hypocalcemia, but ethanol's effect on maximal PTH secretion could impair the ability of the pregnant female to sustain high PTH levels in response to chronic hypocalcemia.

Chronic Ethanol Consumption Impairs Cellular Immune Responses Against HCV NS5 Protein Due to Dendritic Cell Dysfunction

Alcoholic patients with and without chronic liver disease have a high incidence of infection with hepatitis C virus (HCV). Long-term ethanol consumption in mice has been associated with a strikingly reduced CD8(+) cytotoxic T-lymphocyte (CTL) response to HCV nonstructural proteins following DNA-based immunization. This study evaluated the effect of ethanol on dendritic cells (DCs) as a mechanism(s) for reduced CTL activity. Mice were fed an ethanol-containing or isocaloric pair-fed control diet for 8 weeks, followed by DC isolation from the spleen. DCs were evaluated with respect to endocytosis properties, cell surface markers, allostimulatory activity, and cytokine production following stimulation. Immune responses to HCV NS5 protein were generated by genetic immunization. Syngeneic transfer was used to determine if DC dysfunction contributed to abnormal cellular immune responses. Long-term ethanol exposure resulted in a reduced number of splenic DCs but did not alter endocytosis capacity. There was an increase in the myeloid and a reduction in the lymphoid DC population. Ethanol reduced expression of CD40 and CD86 costimulatory molecules on resting DCs, which was corrected following stimulation with lipopolysaccharide or poly I:C. There was impaired allostimulatory activity. Cytokine profiles of DCs isolated from ethanol-fed mice were characterized by enhanced interleukin (IL)-1beta and IL-10 and decreased tumor necrosis factor alpha, IL-12, interferon gamma, and IL-6 secretion. Impaired CTL responses to NS5 were corrected by syngeneic transfer of control DCs. Altered DC function is one of the major changes induced by long-term ethanol consumption, which subsequently impairs the cellular immune response necessary for viral clearance.

Ethanol Suppression of the Hypothalamic Proopiomelanocortin Level and the Splenic NK Cell Cytolytic Activity Is Associated With a Reduction in the Expression of Proinflammatory Cytokines but Not Anti‐inflammatory Cytokines in Neuroendocrine and Immune Cells

Immune signals activate a network of cytokines in the central nervous system (CNS) that in turn causes release of neurotransmitters and hormones to modulate immune cell functions. We have recently shown that hypothalamic beta-endorphin neurons, via inhibition of the sympathetic neuronal activity, activate natural killer (NK) cell function in the spleen, and this communication is disrupted following chronic ethanol administration. Beta-endorphin neuronal function is known to be regulated by various proinflammatory and anti-inflammatory cytokines. The effects of ethanol on the proinflammatory and anti-inflammatory cytokines known to control beta-endorphin neuronal and NK cell functions during immune challenges have not been determined. In the present study, we evaluated the effects of chronic ethanol consumption on the basal and lipopolysaccharide (LPS)-activated NK cells' functions in the spleen, the beta-endorphin peptide precursor proopiomelanocortin (POMC) gene expression in the arcuate nucleus (ARC) of the hypothalamus, and mRNA levels of proinflammatory cytokines interleukin-1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and anti-inflammatory cytokines IL-6 and IL-10 in the spleen and in the ARC. Male rats were ad libitum fed rat chow (ad lib-fed), pair-fed an isocaloric liquid diet, or fed an ethanol-containing liquid diet, and each was treated with LPS (100 microg/kg body weight). After 2 hours, splenocytes and ARC tissues were isolated and used for this study. Splenocytes were used to determine mRNA levels of IL-1beta, TNF-alpha, IL-6, IL-10, granzyme B, and perforin using the real-time RT-PCR assays. Splenocytes were also used to determine the cytolytic activity using a standard 4-hour (51)Cr release assay against YAC-1 lymphoma target cells. Arcuate nuclei were used to determine IL-1beta, TNF-alpha, IL-6, IL-10, and POMC mRNA levels using real-time RT-PCR assays. The results demonstrate that ethanol feeding via a liquid diet for 2 weeks suppressed both basal and LPS-stimulated NK cell cytolytic functions and the levels of cytotoxicity-regulatory perforin and granzyme B mRNAs in the spleen. Ethanol feeding reduced the basal and LPS-stimulated levels of POMC mRNA in the ARC. Ethanol also impaired LPS-induced levels of IL-1beta and TNF-alpha mRNAs both in the spleen and in the ARC. In contrast, ethanol feeding did not cause any significant changes in basal and the LPS-stimulated expression of IL-6 and IL-10 mRNAs in the spleen and of IL-6 mRNA levels in the ARC. These results indicate that ethanol suppression of hypothalamic POMC levels and splenic NK cell functions is associated with a reduced expression of proinflammatory cytokines in neuroendocrine and immune cells.

Oligodendrocyte myelin glycoprotein (OMgp) in rat hippocampus is depleted by chronic ethanol consumption

The hippocampal formation has been shown to be particularly vulnerable to the neurotoxic effects of chronic ethanol consumption. It was hypothesized that this damage was due to the disruption of the expression of neurotrophic factors and certain other proteins within the hippocampus. By using real-time reverse transcription-polymerase chain reaction (RT-PCR) techniques, this study aimed to determine whether chronic ethanol consumption could alter the mRNA expression level of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and oligodendrocyte myelin glycoprotein (OMgp) in the hippocampus. Wistar male rats received an unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole source of fluid from 10 to 29 weeks of age. Control rats had unlimited access to a liquid diet containing an isocaloric amount of sucrose. We found that chronic ethanol consumption did not cause significant changes in the levels of mRNA for BDNF and GDNF. However, OMgp mRNA showed a significant deficit in ethanol-treated animals. It is suggested that this deficit may be related to the demyelination that is commonly observed in human alcoholics and that this may contribute to the functional and cognitive deficits.

Smooth endoplasmic reticulum dilation and degeneration in Purkinje neuron dendrites of aging ethanol-fed female rats

The effects of chronic ethanol consumption on the extensive Purkinje neuron (PN) dendritic arbor of male rats include dilation of the smooth endoplasmic reticulum (SER) and dendritic regression. The purpose of the present study was to examine the molecular layer of female rats for the presence of ethanol-related SER dilation and evidence of degeneration within the PN dendritic arbor. Twenty-one 12-month-old Fischer 344 female rats (n = 7/treatment group) received a liquid ethanol, liquid control, or rat chow diet for a period of 40 weeks. Ethanol-fed rats received 35% of their dietary calories as ethanol. Pair-fed rats received a liquid control diet that was isocaloric to the ethanol diet. Chow-fed rats received standard laboratory rat chow ad libitum. At the end of treatment, tissues from the anterior and posterior lobes of the cerebellar vermis were viewed and photographed with the electron microscope. The diameters of SER profiles were measured and the density of degenerating bodies within the PN dendritic arbor was quantitated. In the posterior lobe, ethanol-related SER dilation was apparent. In the anterior lobe, the density of degenerating bodies within PN dendritic shafts was significantly increased but SER dilation in PN dendritic shafts was absent. These results confirm that SER dilation and dendritic degeneration in PN dendrites may precede and contribute to ethanol-related regression in female rats. In addition, comparison of these results with data obtained in male rats from a previous study suggests that PN dendrites in females may be more sensitive to the effects of ethanol.

Chronic Ethanol Exposure Impairs Neuronal Nitric Oxide Synthase in the Rat Intestine

Nitric oxide (NO), synthesized by neuronal (nNOS), endothelial (eNOS), and inducible (iNOS) nitric oxide synthases, plays an essential role in the physiological functions of the gastrointestinal (GI) tract. Chronic ethanol intake has been shown to interfere with several of these physiological functions, leading to the pathological alterations observed in alcoholic individuals. Our aim therefore was to investigate the effects of chronic ethanol consumption on NOS isoforms in different GI segments. Rats received either 20% aqueous ethanol solution or water for 8 weeks. Tissue samples of the duodenum, jejunum, ileum, and colon of the rats were used for measurement of the NOS activity, protein content, and nNOS immunohistochemistry. Anti-HuC/D immunohistochemistry was used to determine the total number of neurons. Measurement of the physiological constitutive NOS (cNOS) activity revealed a 20 times higher activity in the colon than in the small intestine and after chronic ethanol treatment demonstrated a significant decrease in the jejunum, ileum, and colon, while in the duodenum it remained unchanged compared with the control group. The physiological iNOS activity was higher in the ileum and colon than in the duodenum and jejunum, and these levels were not significantly affected by ethanol. Neuronal nitric oxide synthase immunohistochemistry revealed a significant decrease in the numbers of immunostained cells in all investigated intestinal segments, while the total number of myenteric neurons remained constant. The nNOS protein content measured by Western blotting indicated a significant decrease in the colon after ethanol consumption, while in other intestinal segments change was not detectable. This study has demonstrated for the first time that chronic ethanol consumption has a differential effect on NOS activity, NOS protein content, and the number of nitrergic neurons in different intestinal segments, suggesting that chronic ethanol administration affects the NO pathways in the enteric nervous system.

Effects of Ethanol on Intracorporeal Structures of the Rat

Previous studies demonstrated that acute in vitro exposure of corpus cavernosal tissue to ethanol decreased its response to field stimulation and pharmacological stimulation. In the present study we investigated the effects of chronic ethanol consumption on the ultrastructure of cavernosal smooth muscle cells, elastic fibres and collagen content. Fourteen adult wistar rats were divided into a control group (n = 7, fed a standard diet and tap water) and an alcoholic group (n = 7, fed a standard diet and 5% (v/v) ethanol in drinking water and by increasing the ethanol concentration for every week, at the end of 6th week 30% (v/v) ethanol concentration was attained. Same dose was given until 12th week. At the end of 12th week blood samples were obtained and the ethanol concentrations were determined. The cavernosal tissues were obtained and immunohistochemical examinations were performed. Immunohistochemical analysis revealed that chronic ethanol exposure markedly decreased the content of smooth muscle cells, elastic fibres and collagen type 4. Our findings suggest that in this animal model chronic ethanol exposure decreases the percentage of staining for smooth muscle actin, elastin, and collagen type 4 which are the key structures fundamental for erection.

Effects of Chronic Alcohol and Repeated Deprivations on Dopamine D1 and D2 Receptor Levels in the Extended Amygdala of Inbred Alcohol‐Preferring Rats

Dopaminergic (DA) activity in the extended amygdala (EA) has been known to play a pivotal role in mediating drug and alcohol addiction. Alterations of DA activity within the EA after chronic exposure to alcohol or substances of abuse are considered a major mechanism for the development of alcoholism and addiction. To date, it is not clear how different patterns of chronic alcohol drinking affect DA receptor levels. Therefore, the current studies investigated the effects of chronic ethanol consumption, with or without deprivations, on D1 and D2 receptor densities within the EA. Inbred alcohol-preferring (iP) rats were divided into 3 groups with the following treatments: (1) water for 14 weeks; (2) continuous alcohol (C-Alc) for 14 weeks [24-hour concurrent access to 15 and 30% (v/v) ethanol]; or (3) repeatedly deprived of alcohol (RD-Alc) (24-hour concurrent access to 15 and 30% ethanol for 6 weeks, followed by 2 cycles of 2 weeks of deprivation of and 2 weeks of reexposure to ethanol access). At the end of 14 weeks, the rats were killed for autoradiographic labeling of D1 and D2 receptors. Compared with the water control group, both the C-Alc and the RD-Alc groups displayed increases in D1 receptor binding density in the anterior region of the Acb core, whereas the RD-Alc group displayed additional increases in D1 receptor binding density in anterior regions of the lateral and intercalated nuclei of the amygdala. Additionally, both C-Alc and RD-Alc rats displayed increases in D2 receptor binding density in anterior regions of the Acb shell and core, whereas RD-Alc rats displayed additional increases in D2 receptor binding density in the dorsal striatum. The results of this study indicate that 14-week extended alcohol drinking with continuous chronic or repeated deprivations increase binding sites of D1 and D2 receptors in specific regions of the EA with greater sensitivity in the anterior regions. The repeated deprivation has greater effect on altering D1 and D2 receptor binding sites in the Acb, dorsal striatum, and subamygdala regions. The current result indicates that the two drinking paradigms may have common as well as differential mechanisms on alteration of dopamine receptor-binding sites in specific regions of the EA.

Ethanol‐induced alterations of the antioxidant defense system in rat kidney

We report here the effects of chronic ethanol consumption on the antioxidant defense system in rat kidney. Thirty-two male Wistar rats were randomly divided in two identical groups and were treated as follows: control group (water for fluid) and the ethanol-fed group (2 g/kg body weight/24 h). The animals were sacrificed after 10 weeks, and respectively 30 weeks of ethanol consumption, and the renal tissue was isolated and analyzed. Results revealed that kidney alcohol dehydrogenase activities increased significantly after ethanol administration, but the electrophoretic pattern of alcohol dehydrogenase isoforms was unmodified. The SDS polyacrylamidegel electrophoretic study of kidney proteins has revealed the appearance of two new protein bands after long-term ethanol consumption. The kidney reduced glutathione/oxidized glutathione ratio decreased, indicating an oxidative stress response due to ethanol ingestion. The malondialdehyde contents and xanthine oxidase activities were unchanged. The antioxidant enzymatic defense system showed a different response during the two periods of ethanol administration. After 10 weeks, catalase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase were activated, while superoxide dismutase, glutathione transferase, and gamma-glutamyltranspeptidase levels were stationary. After 30 weeks, superoxide dismutase and glutathione peroxidase activities were unmodified, but catalase, glutathione transferase, gamma-glutamyltranspeptidase, glutathione reductase, and glucose-6-phosphate dehydrogenase activities were significantly increased. Remarkable changes have been registered after 30 weeks of ethanol administration for glutathione reductase and glucose-6-phosphate dehydrogenase activities, including an increase by 106 and 216' of control values, respectively. These results showed specific changes in rat kidney antioxidant system and glutathione status as a consequence of long-term ethanol administration.

Ethanol reduces p38 kinase activation and cyclin D1 protein expression after partial hepatectomy in rats

Chronic ethanol consumption inhibits liver regeneration. We examined the effects of chronic ethanol consumption on two mitogen-activated protein kinases in relation to induction of cell cycle proteins after partial hepatectomy (PH). Male Wistar rats were ethanol-fed (EF) or pair-fed (PF) for 16 weeks before PH. Hepatic activation of extracellular signal regulated kinase (ERK)1/2, p38 kinase and expression of cyclinD1, cyclin-dependent kinase-4 (cdk4) and proliferating cell nuclear antigen (PCNA) were studied. In PF rats, PH-induced p38 activation was evident at 2h and was maximal at 12h. There was a close temporal relationship between p38 activation, cyclin D1 and PCNA expression. Alcohol exposure reduced p38 activation, cyclin D1 and PCNA, each by approximately 50%. ERK1/2 activation occurred during the first 2h post-PH in both EF and PF rats, and there was no later increase in PF rats. In vivo inhibition of p38 suppressed PCNA expression whereas the effect of ERK1/2 inhibition was inconsistent. p38 kinase activation is linked temporally with cyclin D1 expression after PH and appears to exert cell cycle control in the adult liver. p38 signaling also appears to be a target for the inhibitory effect of chronic alcohol on liver regeneration.

Oxidative stress in alcohol-induced rat parotid sialadenosis

This study evaluated the effect of chronic ethanol consumption on the oxidative status of rat parotid and submandibular glands. To identify the endogenous response to ethanol ingestion, the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined. In addition, the antioxidant alpha-tocopherol was supplied to the animals in order to estimate its action in ethanol-associated glandular damage. The thiobarbituric acid reactive substances (TBARS), and the protein carbonyl (PC) content, both markers of cellular oxidative stress on lipid and protein structures, respectively, were recorded. Animals subjected to alcohol ingestion showed a low body growth rate with concomitant enlargement of absolute and relative parotid wet weight, compared with pair-fed calorie-controlled rats. Parotid glands of ethanol-treated animals showed increased SOD and GPx activity, and alpha-tocopherol was able to reduce their activities to the control levels. TBARS and PC were enhanced after chronic ethanol treatment in rat parotids. Supplemental alpha-tocopherol suppressed the oxidative ethanol-induced damage in lipid without affecting induced protein oxidation. Submandibular glands revealed no alterations in the weight, enzymatic and oxidative parameters tested due to ethanol and/or alpha-tocopherol ingestion. These findings indicate the involvement of oxidative stress in parotid gland sialadenosis due to ethanol consumption and the capability of alpha-tocopherol to halt lipid damage, although this low-molecular antioxidant compound leads to neither increased glandular weight nor protein oxidation in ethanol-induced parotid alterations.

The effects of chronic ethanol consumption and withdrawal on passive avoidance task and serum cholinesterase level in rats

The effects of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase (ChE) activity and passive avoidance task in rats were investigated. Ethanol was administered to rats by a modified liquid diet with 4.8% (v/v) ethanol for 3 days followed by 25 days on a liquid diet in which the ethanol concentration was increased to 7.2%. Control rats were pair fed with an isocaloric liquid diet not containing ethanol. ChE activity and blood ethanol concentration were measured at the end of the 4.8% ethanol consumption and after 25 days of ethanol (7.2%) feeding and, just before and 24th and 72nd h of ethanol withdrawal period. Passive avoidance acquisition was evaluated for 150 s (cut-off time) in three individual groups of ethanol-administered, ethanol withdrawn (24th and 72nd h of withdrawal) and control rats. Locomotor activity of the rats was also measured and evaluated. The daily ethanol consumption of the rats ranged from 11.5 to 14.9 g/kg. ChE activities of the ethanol feeding rats were significantly increased as compared to control rats at the 3rd (4.8% ethanol) and 25th days of chronic ethanol (7.2%) consumption and 24th h of ethanol withdrawal. It returned to control values at the 72nd h of the withdrawal. Blood ethanol levels were measured as 200 and 2.2 mg/dl at just before ethanol withdrawal and 24th h of ethanol withdrawal, respectively. Both chronic ethanol consumption and late period of ethanol withdrawal produced some significant decreases in passive avoidance latency of the rats. Our results suggest that chronic ethanol consumption and late period of ethanol withdrawal may be related to impairment of passive avoidance task in rats. In addition, serum ChE levels do not seem to be involved in impairment of cognitive functions in ethanol dependent-rats.

Effects of chronic ethanol administration and ethanol withdrawal on cyclic guanosine 3′,5′-monophosphate (cGMP) levels in the rat brain

The main objective of the present study is to investigate the possible effects of chronic ethanol consumption and ethanol withdrawal on cyclic guanosine 3′, 5′-monophosphate (cGMP) levels in cerebral cortex, striatum, hippocampus and hypothalamus of rat brain. Ethanol was given to female Wistar rats (225–270 g) by a liquid diet for 21 days. cGMP levels were measured in respective brain regions using an EIA kit at 7th, 14th and 21st days of ethanol ingestion and at 6th and 24th h of ethanol withdrawal. cGMP levels in cortex, striatum and hippocampus but not hypothalamus were found significantly increased at 14th and 21st days of ethanol consumption. The most prominent increase was observed in striatal tissues (approximately 350%). cGMP levels of striatum and hippocampus were still remaining significantly high at 6th h of ethanol withdrawal. Blood ethanol levels were found as 115.60, 50.0 and 7.0 mg/dl just before and after 6 and 24 h of ethanol withdrawal, respectively and audiogenic seizures also occurred at 6th h of ethanol withdrawal with an incidence of 75% in individual parallel groups. Our results suggest that changes of cGMP levels in cerebral cortex, striatum and hippocampus might participate in the mechanism of ethanol dependence and withdrawal in rats.

Alcohol and hepatitis C virus core protein additively increase lipid peroxidation and synergistically trigger hepatic cytokine expression in a transgenic mouse model

Background/Aims: Alcohol consumption accelerates the appearance of liver fibrosis and hepatocellular carcinoma in patients with chronic hepatitis C virus (HCV) infection, but the mechanisms of these interactions are unknown. We therefore investigated the effects of chronic ethanol consumption in HCV core protein-expressing transgenic mice. Methods: Ethanol was progressively added (up to 20%) to the drinking water that was given ad libidum. Results: In vivo fatty acid oxidation was not inhibited by ethanol consumption and/or HCV core expression. Both chronic ethanol consumption and HCV core expression decreased hepatic lipoprotein secretion and caused steatosis, but had no additive effects on lipoprotein secretion or steatosis. However, chronic ethanol consumption and HCV core protein additively increased lipid peroxidation and acted synergistically to increase the hepatic expression of transforming growth factor-β (TGF-β) and, to a less extent, tumor necrosis factor-α (TNF-α). Conclusions: HCV core protein expression and chronic alcohol consumption have no effects on in vivo fatty acid oxidation and do not additively impair hepatic lipoprotein secretion, but additively increase hepatic lipid peroxidation and synergistically increase hepatic TNF-α and TGF-β expression. These effects may be involved in the activation of fibrogenesis and the development of hepatocellular carcinoma in patients cumulating alcohol abuse and HCV infection.

The effects of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase activity in rats.

The effect of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase (ChE) activity was investigated in female Wistar rats. Ethanol was administered by a modified liquid diet with 4.8% (v/v) ethanol for 3 days followed by 25 days on a liquid diet in which the ethanol concentration was increased to 7.2%. Control rats were pair-fed with an isocaloric liquid diet not containing ethanol. The blood ethanol concentration and serum ChE activity were measured at the end of the 4.8% ethanol consumption period; after 7, 14 and 35 days of ethanol (7.2%) consumption, and at 24 and 72 h after ethanol withdrawal following ethanol consumption of 35 days. Daily ethanol consumption of the rats ranged from 11.5 to 14.9 g/kg. Serum ChE activity was found significantly increased from the 3rd day of ethanol (4.8%) consumption. Serum ChE activities of the rats receiving 7.2% ethanol also increased significantly compared with rats ingesting 4.8% ethanol. Blood ethanol levels were measured as 121 and 0.88 mg/dl on the 35th day of ethanol (7.2%) consumption (just before ethanol withdrawal) and after 24 h of ethanol withdrawal, respectively. Increased serum ChE activity (1968 U/l) was still observed (1942 U/l) after 24 h of ethanol withdrawal. ChE activity returned to control levels (501 U/l) after 72 h of ethanol withdrawal. Audiogenic seizures indicating development of physical dependence on ethanol were also observed after 8 h of ethanol withdrawal in another individual group of ethanol-fed rats. Our results show that serum ChE activity is increased by chronic ethanol consumption in rats and that this increase is affected by ethanol concentration and duration of ethanol ingestion.

The Effects of Chronic Ethanol Consumption During Early Pregnancy on Conceptus Health and Uterine Function in Pigs

Background: Maternal ethanol consumption impairs fetal health, but it is unclear if this occurs through direct actions on the conceptus or indirectly through effects on the uterus. The objective of this study was to determine if chronic ethanol consumption in swine would impair early embryonic and fetal health either through direct effects on the conceptus or indirect effects on the endometrium.Methods: Four experiments evaluated the effects of chronic ethanol consumption during early pregnancy. Female pigs were fed either 350 ml of 95% ethanol or an isocaloric amount of dextrose at 10 to 14‐hr intervals beginning on day 10 after pubertal estrus and continuing until ovariohysterectomy 11 to 35 days after mating. At the second estrus, pigs were mated to a fertile boar that did not consume alcohol.Results: In experiment 1, ethanol consumption increased (p < 0.01) blood alcohol concentrations that peaked 2–3 hr after feeding. In experiment 2, ethanol was detectable in uterine flushings 2 hr after feeding on day 11 of pregnancy and was highly correlated (r= 0.989, p < 0.001) with blood alcohol concentration. In experiment 3, ethanol consumption did not affect endometrial phospholipase C activity on days 11 and 16 of pregnancy but decreased (p < 0.05) basal endometrial prostaglandin F2α production on day 16. However, ethanol consumption did not decrease the number of conceptuses on day 11 or conceptus DNA content on days 11 or 16. In experiment 4, ethanol consumption decreased (p < 0.05) fetal survival rate to 58% versus 85% in dextrose‐fed controls on day 35 of pregnancy. For viable conceptuses, ethanol consumption reduced (p < 0.01) fetal weight, fetal crown‐rump length, placental weight and volume of placental (chorio‐allantoic + amniotic) fluid.Conclusion: These results indicate that chronic ethanol consumption may impair conceptus health directly or indirectly through actions upon the endometrium. Thus, the pig may be a valuable experimental model for studies on the effects of maternal alcohol consumption on conceptus development.