Long-term Ethanol Intake Research Articles

Salidroside ameliorates memory impairment following long-term ethanol intake in rats by modulating the altered intestinal microbiota content and hippocampal gene expression.

Salidroside (Sal), the main component of a famous herb Rhodiola rosea L, enhances memory performance and reduces fatigue. Therefore, this study assessed the effect of Sal on memory impairment induced by a long-term intake of ethanol (EtOH) in rats and investigated its relevant mechanisms using gut microbiota metagenomic analysis and hippocampal transcriptomic analysis. Eighteen male SD rats were divided into the normal control group (CON group), EtOH model group (Model group), and Sal treatment group (Sal group). The rats in the Model and Sal groups intragastrically (i.g.) received 2 g/kg EtOH for 30 consecutive days, whereas the CON group was given an equal volume of distilled water. Meanwhile, the rats in the Sal group were administered i.g. 30 mg/kg Sal 60 min after EtOH intake. All rats were tested in the eight-arm maze for their memory function every 3 days. On the 30th day, metagenomic analyses of gut microbiota and transcriptomic analyses of the hippocampus were performed. Compared with the Model group, Sal treatment reduced the total time to complete the eight-arm maze task, decreased the number of arm entries, and abated the working memory error that was significant from the 9th day. Additionally, Sal intervention improved the gut microbiota composition, such as the increased abundance of Actinobacteria and Bifidobacterium, which was related to the metabolism of amino acids and terpenoid carbohydrate, endocrine function, and signal transduction by neurotransmitters. In the hippocampus, the EtOH intake differentially expressed 68 genes (54 genes increased, whereas 14 genes decreased), compared with the CON group, whereas Sal intervention affected these changes: 15 genes increased whereas 11 genes decreased. And, enrichment analyses revealed these genes were related to the structural components of the ribosome, mRNA splicing process, protein translation, mitochondria function, and immunological reaction. Finally, a correlation analysis found the memory impairment was positively correlated with the abnormal upregulation of Tomm7 but negatively correlated with decreased abundance of gut Alistipes_indistinctus, Lactobacillus_taiwanensis, Lactobacillus_paragasseri, and Lactobacillus johnsonii. Sal improved memory impairment caused by long-term EtOH intake in rats, which may be related to its regulation of gut dysbiosis and hippocampal dysfunction.

MiR-34a regulates macrophage-associated inflammation and angiogenesis in alcohol-induced liver injury.

Alcohol-associated liver disease (ALD) is a syndrome of progressive inflammatory liver injury and vascular remodeling associated with long-term heavy intake of ethanol. Elevated miR-34a expression, macrophage activation, and liver angiogenesis in ALD and their correlation with the degree of inflammation and fibrosis have been reported. The current study aims to characterize the functional role of miR-34a-regulated macrophage- associated angiogenesis during ALD. We identified that knockout of miR-34a in 5 weeks of ethanol-fed mice significantly decreased the total liver histopathology score and miR-34a expression, along with the inhibited liver inflammation and angiogenesis by reduced macrophage infiltration and CD31/VEGF-A expression. Treatment of murine macrophages (RAW 264.7) with lipopolysaccharide (20 ng/mL) for 24 h significantly increased miR-34a expression, along with the enhanced M1/M2 phenotype changes and reduced Sirt1 expression. Silencing of miR-34a significantly increased oxygen consumption rate (OCR) in ethanol treated macrophages, and decreased lipopolysaccharide-induced activation of M1 phenotypes in cultured macrophages by upregulation of Sirt1. Furthermore, the expressions of miR-34a and its target Sirt1, macrophage polarization, and angiogenic phenotypes were significantly altered in isolated macrophages from ethanol-fed mouse liver specimens compared to controls. TLR4/miR-34a knockout mice and miR-34a Morpho/AS treated mice displayed less sensitivity to alcohol-associated injury, along with the enhanced Sirt1 and M2 markers in isolated macrophages, as well as reduced angiogenesis and hepatic expressions of inflammation markers MPO, LY6G, CXCL1, and CXCL2. Our results show that miR-34a-mediated Sirt1 signaling in macrophages is essential for steatohepatitis and angiogenesis during alcohol-induced liver injury. These findings provide new insight into the function of microRNA-regulated liver inflammation and angiogenesis and the implications for reversing steatohepatitis with potential therapeutic benefits in human alcohol-associated liver diseases.

Effects of Long-Term Ethanol Consumption on Learning-Memory Functions in Mice and the Mechanisms Involved

To investigate the effect of long-term ethanol consumption on learning-memory functions in mice and the mechanisms involved. Thirty male C57BL6/J mice were randomly assigned to 3 groups, with 10 mice in each group. The three groups included a control group in which the mice were given water ad libitum for 30 days, a long-term ethanol consumption group, or the EtOH group, in which the mice were given 6% (volume fraction) ethanol ad libitum for 30 days, and a long-term alcoholism group, or the EtOH+G group, in which the mice were given 5% (volume fraction) ethanol ad libitum for 30 days plus intermittent intragastric gavage of 20% ethanol at 3.5 g per kilogram body mass once every three days. After 30 days, the learning-memory functions of the mice were evaluated. At the conclusion of the experiment, the brain tissue of the mice was collected in order to examine the oxygen consumption rate (OCR) of mitochondria, the levels of pan-acetylation and protein oxidative stress in the hippocampal tissue, and the expression of sirtuin-3 (SIRT3) in hippocampus. Morris water maze test showed that, compared with those of the control group, the times of crossing the platform and the percentage of platform time in the EtOH group and the EtOH+G group were both lower, and the EtOH+G group had the lowest results ( P<0.05). Western blot results showed that long-term ethanol intake increased the levels of protein oxidative stress and pan-acetylation in the hippocampal tissue and down-regulated SIRT3 expression of hippocampal mitochondria. The results of mitochondrial complex Ⅱ respiration showed that the brain mitochondrial 3-state respiration in the EtOH group and the EtOH+G group was lower than that in the control group ( P<0.05). Compared that with the control group, the mitochondrial maximum respiration in EtOH+G group was decreased ( P<0.05). Both long-term ethanol consumption and long-term alcoholism can reduce learning-memory functions and long-term alcoholism has the greater impact of the two. The potential mechanism may involve the down-regulation of the expression of SIRT3 protein in the hippocampus, which results in an increased level of pan-acetylation and enhanced expression of oxidative stress protein in the hippocampus, affects the mitochondrial functions of the brain, inhibits the oxidative phosphorylation capacity of mitochondrial complex Ⅱ, reduces the ATP energy supply of the brain tissue, and thus affects the learning-memory function.

Impact of acute schistosomiasis mansoni and long-term ethanol intake on mouse liver pathology

While the effect of ethanol and schistosomiasis mansoni on liver injury has been well-documented, the influence of comorbidity on liver pathology remains unclear. To address this gap, schistosomiasis-infected mice were given one daily dose of 18% ethanol for 28 consecutive days, from day 35 post-infection. Mice were assigned to four groups: A. control; B. uninfected/ethanol gavage; C. infected; and D. infected/ethanol gavage. At day 64 post-infection, mice were euthanized by CO2 asphyxiation, livers were excised, fixed in 10% buffered formalin, paraffin embedded and cut into 5 μm sections. These were stained with hematoxylin and eosin (HE), Lennert's Giemsa and picrosirius red (for polarization microscopy) to assess histopathological and stereological changes. Group B showed alcoholic liver disease (ALD), including microsteatosis, hepatocyte karyopyknosis, karyorrhexis, karyolysis, increased frequency of Kupffer cells, hydropic degeneration of hepatocyte, thickened plasma membrane and binucleated hepatocytes. Infected mice showed typical exudative and exudative-productive hepatic granulomas, and destruction of the adjacent hepatic parenchyma, resulting in necrotic tissue and periovular leukocyte infiltrate. Group D showed hyperemia (parenchymal panlobular lesions), and liquefactive necrosis in hepatic abscess area. There was also reduced liver collagen deposition (−76%; p = 0.0001) and reduced microsteatosis (−80%, p = 0.0079) compared to group C and group B, respectively. In conclusion, comorbidity exacerbated liver damage.

Bone impairment in adolescent female rats chronically exposed to ethanol

Ethanol consumption has increased among teenagers worldwide considerably,including females. Long-term ethanol consumption in women has been reported to cause bone metabolism imbalance. However, only few studies are available on the impact of long-term ethanol consumptionon bone morphology during adolescence. Here, we report the effects of chronic ethanol consumption on bone structure in adolescent female rats. Twenty female Wistar rats (35 days old) received, by gavage, distilled water (control) or ethanol (6.5 g/kg/day, 22.5% w/v) once daily for 55 days. After ethanol administration, animals were perfused, and the femora were collected. Morphometric evaluations were performed by electron microscopy scanning. Femora length, cortical bone thickness and medullar bone diameter was measured. The results demonstrated that ethanol exposure during adolescence reduced the length of femurs, with a decrease of the anterior thickness, posterior thickness, and mid-lateral diameter (P&lt;0.05). Thus, long-term ethanol intake may lead to alterations on bone morphometry, reducing the thickness of compact bone and femur length in adolescent females.

Розвиток запалення в травному тракті щурів після тривалого введення алкоголю

The purpose of the work was to experimentally study the chronic alcohol intoxication on the indicators of inflammation and lipid peroxidation in the gastrointestinal system. Materials and methods. Ethyl alcohol was added to the water for 2-month-old male rats, ranging from 5% to 15% for 108 days. In homogenates of mucous membranes of the gastrointestinal tract and liver, the activity of elastase enzymes, acid phosphatase and the concentration of malonic dialdehyde were determined, in serum – elastase activity and malonic dialdehyde content. Results and discussion. Biochemical research of one of the markers of inflammation (elastase activity) in rats found a probable increase of elastase activity in different parts of the digestive tract after prolonged alcohol consumption, regardless of the sex of the animals. Thus, in the serum of rats after the introduction of ethanol, the activity of elastase increased by 71.7%, in the oral mucosa – by 29.2%, in the gastric mucosa – by 55.5%, in the liver – by 29.0%. In the small and large intestine, the level of this marker of inflammation has changed slightly. The level of elastase activity shows the degree of accumulation of leukocytes in the tissues as a result of the development of the inflammatory process. Acid phosphatase activity in the oral mucosa of rats treated with ethanol increased by 47.4%, in the gastric mucosa – by 30.3%, in the mucous membrane of the small intestine – by 37.4%, in the mucous membrane of the colon – by 40.4%, in the liver – by 112.6%. Activation of acid phosphatase, along with other lysosomal enzymes, is the primary inflammatory response that triggers the production of mediators, which in turn cause secondary tissue alteration in subsequent stages of the inflammatory process. Therefore, the results obtained on the activation of acid phosphatase along with elastase indicate the presence of inflammation in the mucous membranes of the digestive tract, and especially in the liver of rats chronically treated with ethanol. The introduction of alcohol also led to an increase in the concentration of malonic dialdehyde in the mucous membranes: the oral cavity – by 20.3%, the stomach – by 32.3%, the small intestine – by 96.6%, the colon – by 50.2%, in the liver – by 39.4%, in serum – by 33.3%. A significant increase in the level of malonic dialdehyde in the tissues of the digestive tract of rats after long-term intake of ethanol is a sign of activation of lipid peroxidation and intensification of oxidative stress reactions. Conclusion. The results of the study of elastase activity indicate the development of inflammation in the mucous membranes of the gastrointestinal tract, liver and serum of rats under the influence of chronic administration of ethanol. Increased acid phosphatase activity in the tissues of the gastrointestinal tract after prolonged use of ethanol indicates damage to cell membranes, which is a consequence of inflammation. A significant increase in the level of malonic dialdehyde in the mucous membranes of the gastrointestinal tract, liver and serum of rats after chronic ethanol intake is a sign of intensification of oxidative stress reactions

Long-term low-dose ethanol intake improves healthspan and resists high-fat diet-induced obesity in mice.

Numerous epidemiological studies have reported that moderate alcohol drinking has beneficial effects. However, few studies have focused on the beneficial effects of ethanol, the common component in alcoholic beverages. Here we fed the C57BL/6 mice with 3.5% v/v ethanol as drinking water substitute to investigate the effects of long-term low-dose ethanol intake in vivo. We evaluated the metabolic rate and mitochondrial function of the long-term low-dose ethanol-intake (LLE) mice, assessed the exercise ability of LLE mice, and fed the LLE mice with a high-fat diet to investigate the potential impact of ethanol on it. The LLE mice showed improved thermogenic activity, physical performance, and mitochondrial function, as well as resistance against the high-fat diet-induced obesity with elevated insulin sensitivity and subdued inflammation. Our results suggest that long-term low-dose ethanol intake can improve healthspan and resist high-fat diet-induced obesity in mice. It may provide new insight into understanding the protective effects of moderate alcohol drinking.

Research Progress and Forensic Identification of Alcoholic Cardiomyopathy.

With the rapid development of the social economy in China, the incidence of diseases caused by excessive drinking is gradually increasing as well. Alcoholic cardiomyopathy refers to long-term high intake of ethanol, and has typical dilated cardiomyopathy characteristics, such as, hemodynamic changes, symptoms, signs, and morphological features. It is a kind of cardiomyopathy that excludes other causes of dilated cardiomyopathy. Due to the lack of specific pathological changes, the forensic pathological identification of alcoholic cardiomyopathy can only be based on the patient's medical history and by ruling out other causes of cardiomyopathy. This paper reviews the pathogenesis and forensic identification of alcoholic cardiomyopathy in order to provide reference for forensic pathologists and clinicians.

Modulation of serotonin and noradrenaline in the BLA by pindolol reduces long-term ethanol intake.

Repeated cycles of binge-like alcohol consumption and abstinence change the activity of several neurotransmitter systems. Some of these changes are consolidated following prolonged alcohol use and are thought to play an important role in the development of dependence. We have previously shown that systemic administration of the dual beta-adrenergic antagonist and 5-HT1A/1B partial agonist pindolol selectively reduces long-term but not short-term binge-like consumption of ethanol and alters excitatory postsynaptic currents in basolateral amygdala (BLA) principal neurons. The aim of this study was to investigate the effects of pindolol microinfusions in the BLA on long-term ethanol intake using the drinking-in-the-dark paradigm in mice. We also microinfused RU24969 (5-HT1A/1B receptor partial agonist) and CGP12177 (β1/2 adrenergic antagonist) following long-term ethanol intake and determined the densities of 5-HT1A/1B receptors and β1/2 adrenergic in the BLA following short-term (4weeks) and long-term ethanol (12weeks) consumption. We show that intra-BLA infusion of pindolol (1000pmol/0.5μl), RU24969 (0.3 and 3pmol/0.5μl) and CGP12177 (500pmol/0.5μl) produce robust decreases in long-term ethanol consumption. Additionally, we identified reduced β1/2 adrenergic receptor expression and no change in 5-HT1A/1B receptor density in the BLA of long-term ethanol-consuming mice. Collectively, our data highlight the effects of pindolol on voluntary, binge-like ethanol consumption behavior following long-term intake.

Ethanol-Induced Changes in PKCε: From Cell to Behavior.

The long-term binge intake of ethanol causes neuroadaptive changes that lead to drinkers requiring higher amounts of ethanol to experience its effects. This neuroadaptation can be partly attributed to the modulation of numerous neurotransmitter receptors by the various protein kinases C (PKCs). PKCs are enzymes that control cellular activities by regulating other proteins via phosphorylation. Among the various isoforms of PKC, PKCε is the most implicated in ethanol-induced biochemical and behavioral changes. Ethanol exposure causes changes to PKCε expression and localization in various brain regions that mediate addiction-favoring plasticity. Ethanol works in conjunction with numerous upstream kinases and second messenger activators to affect cellular PKCε expression. Chauffeur proteins, such as receptors for activated C kinase (RACKs), cause the translocation of PKCε to aberrant sites and mediate ethanol-induced changes. In this article, we aim to review the following: the general structure and function of PKCε, ethanol-induced changes in PKCε expression, the regulation of ethanol-induced PKCε activities in DAG-dependent and DAG-independent environments, the mechanisms underlying PKCε-RACKε translocation in the presence of ethanol, and the existing literature on the role of PKCε in ethanol-induced neurobehavioral changes, with the goal of creating a working model upon which further research can build.

Changes in the female arcuate nucleus morphology and neurochemistry after chronic ethanol consumption and long-term withdrawal

Ethanol is a macronutrient whose intake is a form of ingestive behavior, sharing physiological mechanisms with food intake. Chronic ethanol consumption is detrimental to the brain, inducing gender-dependent neuronal damage. The hypothalamic arcuate nucleus (ARN) is a modulator of food intake that expresses feeding-regulatory neuropeptides, such as alpha melanocyte-stimulating hormone (α-MSH) and neuropeptide Y (NPY). Despite its involvement in pathways associated with eating disorders and ethanol abuse, the impact of ethanol consumption and withdrawal in the ARN structure and neurochemistry in females is unknown. We used female rat models of 20% ethanol consumption for six months and of subsequent ethanol withdrawal for two months. Food intake and body weights were measured. ARN morphology was stereologically analyzed to estimate its volume, total number of neurons and total number of neurons expressing NPY, α-MSH, tyrosine hydroxylase (TH) and estrogen receptor alpha (ERα). Ethanol decreased energy intake and body weights. However, it did not change the ARN morphology or the expression of NPY, α-MSH and TH, while increasing ERα expression. Withdrawal induced a significant volume and neuron loss that was accompanied by an increase in NPY expression without affecting α-MSH and TH expression. These findings indicate that the female ARN is more vulnerable to withdrawal than to excess alcohol. The data also support the hypothesis that the same pathways that regulate the expression of NPY and α-MSH in long-term ethanol intake may regulate food intake. The present model of long-term ethanol intake and withdrawal induces new physiological conditions with adaptive responses.

Circadian activity rhythms and voluntary ethanol intake in male and female ethanol-preferring rats: Effects of long-term ethanol access

Chronic alcohol (ethanol) intake alters fundamental properties of the circadian clock. While previous studies have reported significant alterations in free-running circadian period during chronic ethanol access, these effects are typically subtle and appear to require high levels of intake. In the present study we examined the effects of long-term voluntary ethanol intake on ethanol consumption and free-running circadian period in male and female, selectively bred ethanol-preferring P and HAD2 rats. In light of previous reports that intermittent access can result in escalated ethanol intake, an initial 2-week water-only baseline was followed by either continuous or intermittent ethanol access (i.e., alternating 15-day epochs of ethanol access and ethanol deprivation) in separate groups of rats. Thus, animals were exposed to either 135 days of continuous ethanol access or to five 15-day access periods alternating with four 15-day periods of ethanol deprivation. Animals were maintained individually in running-wheel cages under continuous darkness throughout the experiment to allow monitoring of free-running activity and drinking rhythms, and 10% (v/v) ethanol and plain water were available continuously via separate drinking tubes during ethanol access. While there were no initial sex differences in ethanol drinking, ethanol preference increased progressively in male P and HAD2 rats under both continuous and intermittent-access conditions, and eventually exceeded that seen in females. Free-running period shortened during the initial ethanol-access epoch in all groups, but the persistence of this effect showed complex dependence on sex, breeding line, and ethanol-access schedule. Finally, while females of both breeding lines displayed higher levels of locomotor activity than males, there was little evidence for modulation of activity level by ethanol access. These results are consistent with previous findings that chronic ethanol intake alters free-running circadian period, and show further that the development of chronobiological tolerance to ethanol may vary by sex and genotype.

Region-specific depression of striatal activity in Wistar rat by modest ethanol consumption over a ten-month period

The nucleus accumbens (nAc) is the primary target for the mesolimbic dopamine system and a key brain region for the reinforcing effects displayed by drugs of abuse, including ethanol. During the transition from recreational to compulsive consumption of reinforcing drugs, however, the dorsal striatum seems to be recruited. Understanding how synaptic activity is altered in a sub-region specific manner in the striatum during the course of long-term drug consumption thus could be essential for understanding the long-lasting changes produced by addictive substances, including ethanol. Here we evaluated synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc) of single-housed Wistar rats consuming water, or water and ethanol, for up to 10 months. Even though ethanol intake was moderate, it was sufficient to decrease input/output function in response to stimulation intensity in the DLS, while recorded population spike (PS) amplitudes in the nAc were unaffected. Striatal disinhibition induced by the GABAA receptor antagonist bicuculline had a slower onset in rats that had consumed ethanol for 2 months, and was significantly depressed in slices from rats that had consumed ethanol for 4 months. Bicuculline-induced disinhibition in the nAc, on the other hand, was not significantly altered by long-term ethanol intake. Changes in PS amplitude induced by taurine or the glycine receptor antagonist strychnine were not significantly altered by ethanol in any brain region. Even though input/output function was not significantly affected by age, there was a significant decline in antagonist-induced disinhibition in brain slices from aged rats. The data presented here suggest that even modest consumption of ethanol is sufficient to alter neurotransmission in the striatum, while synaptic activity appears to be relatively well-preserved in the nAc during the course of long-term ethanol consumption.

The influence of ethanol intake on RhoA/Rho kinase signaling pathway in corpus cavernosum of OLETF rats

To investigate the effect of the ethanol on corpus cavernosum of the type 2 diabetes mellitus (type 2 DM) rat, since previous studies have reported the positive effect of moderate drinking on type 2 DM and endothelial function. Otsuka Long Evans Tokushima Fatty (OLETF, n = 28) and Long Evans Tokushima Otsuka (LETO, n = 28) male rats were assigned to four groups: control (LETO, n = 14), control/ethanol (LETO with ethanol, n = 14), fatty (OLETF, n = 14) and fatty/ethanol (OLETF with ethanol, n = 14). The control/ethanol and fatty/ethanol groups were fed Lieber-DeCarli Regular EtOH. After 10 weeks, an intraperitoneal glucose tolerance test (IPGTT) was performed. RT-PCR and Western blot analyses of the RhoA/Rho kinase in the corpus cavernosum were performed. The expression of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) in the corpus cavernosum was evaluated by immunohistochemistry. After a 10-week ethanol intake, the body weight and the IPGTT of the fatty/ethanol group were significantly lower compared with the fatty group (p < 0.05). A significantly increased mRNA and protein expression in the fatty group was observed compared with the control group by RT-PCR and Western blot analyses (p < 0.05): A significantly decreased expression was observed in the fatty/ethanol group compared with the fatty group (p < 0.05). The significantly increased expression of eNOS was observed in the fatty/ethanol group compared with the fatty group by immunohistochemistry. Long-term ethanol intake may preserve the erectile function in type 2 DM through the down-regulation of the RhoA/Rho kinase pathway.

Sex Influence on the Formation of Alcohol Preference and Behavior in Rats during the Long-Term Caffeine and Ethanol Intake

Last years the intake of energy drinks (drinks containing caffeine and alcohol) both in young men and women has been increased. However the investigators do not pay attention to the analysis of gender differences. The goal of the study was the investigation of ethanol and caffeine influence on the alcohol preference formation and behavior in male and female rats under the conditions of long-term experiment. It has been found that six month intake of caffeine, ethanol and their combination has led to the increase of alcohol preference both in male and female rats. Alcohol preference was formed earlier in rats consumed combination of caffeine with ethanol, later on in rats consumed ethanol. In animals consumed caffeine the strong alcohol preference did not form up to the end of the experiment. Alcohol preference was higher in female rats consuming caffeine with ethanol and pure ethanol solution compared to male rats. .Behavioral activity significantly increased in females consumed caffeine and caffeine with ethanol, compared to animals received ethanol and controls. Similar tendency was observed in male rats. The anxiety level was significantly higher in females rats in all experimental groups compared to controls, while males did not demonstrate increased anxiety.

Increased Circulating Vasopressin May Account for Ethanol-induced Hypertension in Rats

Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic vasopressin levels in rats. In this work, we investigated the involvement of systemic vasopressin in the hypertension evoked in rats by long-term ethanol (20% vol/vol) intake for 2 weeks, by systemic treatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (50 microg/kg). Moreover, plasma arginine-vasopressin (AVP) content was quantified using an AVP radioimmunoassay and the expression of vasopressin mRNA in the supraoptic (SON) and paraventricular (PVN) nuclei was measured using real-time PCR. Mild hypertension was observed after 2 weeks of ethanol treatment when compared with control animals. Moreover, an increase in both the expression of vasopressin mRNA and the vasopressin blood content was observed in ethanol-treated rats in comparison to the control group. Basal blood pressure levels of ethanol-treated animals were significantly reduced by IV treatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP. However, dTyr(CH2)5(Me)AVP had no effect on the blood pressure of control animals. The results indicate that mild hypertension is already observed at an early phase of ethanol consumption in rats. Because the content of circulating vasopressin was increased in ethanol-treated rats and their basal blood pressure returned to control levels after IV treatment with a V1-vasopressin receptor antagonist, it is proposed that increased circulating vasopressin content may mediate the hypertension observed in ethanol-treated rats.

Chronic alcoholism and esophageal motor activity: A 24‐h ambulatory manometry study

Stationary esophageal manometry has shown esophageal motor abnormalities in patients with chronic alcoholism. The abnormalities identified in different studies are not consistent. Twenty-four hour ambulatory esophageal manometry enables monitoring of esophageal motor activity under a variety of physiological conditions and gives a more complete assessment. Twenty-four hour ambulatory esophageal manometry and pH-metry were performed using a combined pH and pressure catheter. Subjects with chronic alcoholism with no other illness and not in withdrawal were studied with age- and sex-matched healthy controls. Autonomic nerve functions tests were performed in all subjects. Twenty-three chronic alcoholic subjects and 12 control subjects completed the study. The median ethanol consumption was 95 g/day (range 75 -175 g/day) for 12 years (range 5-30 years) among alcoholic subjects. Eight alcoholic subjects had heartburn and regurgitation but none had dysphagia. Ten (43%) alcoholic subjects had autonomic neuropathy and four (17%) had increased gastroesophageal acid reflux. Lower esophageal sphincter hypertension was observed in alcoholic subjects with autonomic neuropathy. Esophageal body motility parameters (i.e. frequency, duration, amplitude and percentage of peristaltic waves) were not significantly different between alcoholic subjects and controls. Results of ambulatory esophageal manometry on subjects with chronic alcoholism seem to indicate that long-term ethanol intake has no major effects on esophageal motor activity other than lower esophageal sphincter hypertension among those with alcoholic autonomic neuropathy.

Chronic ethanol consumption alters cardiovascular functions in conscious rats

Chronic ethanol intake and hypertension are related. In the present work, we investigated the effect of chronic ethanol (20% v/v) intake for 2, 6 and 10 weeks on basal arterial blood pressure, baroreflex and heart rate levels, as well as on the cardiovascular responses to the infusion of vasoactive agents in unanesthetized rats. Mild hypertension was observed after 2 weeks, 6 weeks or 10 weeks of treatment. On the other hand, no changes were observed in heart rate after long-term ethanol intake. Similar baroreflex changes were observed in 2- or 6-week ethanol-treated rats, and affected all parameters of baroreflex sigmoid curves, when compared to the control group. These changes were characterized by an enhanced baroreflex sympathetic component and a reduction in the baroreflex parasympathetic component. No differences in baroreflex parameters were observed in 10-week ethanol-treated animals. The pressor effects of i.v. phenylephrine were enhanced in 2-week ethanol-treated rats; not affected in 6-week treated animals and reduced in 10-week ethanol-treated rats, when compared to respective control and isocaloric groups. The hypotensive response to i.v. sodium nitroprusside (SNP) was enhanced at all different times of treatment, when compared to respective control and isocaloric groups. In conclusion, the present findings showed increased arterial pressure in the early phase of chronic ethanol consumption, which was consequent of rise in both systolic and diastolic pressures. Ethanol intake affected both the sympathetic and the parasympathetic components of the baroreflex. Vascular responsiveness to the pressor agent phenylephrine was initially enhanced and later on decreased during chronic ethanol intake. Vascular responsiveness to the depressor agent SNP was enhanced during chronic ethanol intake.

#74 Steroid resistance and anxiety-like behaviors develop in aged, socially defeated CD-1 mice

The nucleus accumbens (nAc) is the primary target for the mesolimbic dopamine system and a key brain region for the reinforcing effects displayed by drugs of abuse, including ethanol. During the transition from recreational to compulsive consumption of reinforcing drugs, however, the dorsal striatum seems to be recruited. Understanding how synaptic activity is altered in a sub-region specific manner in the striatum during the course of long-term drug consumption thus could be essential for understanding the long-lasting changes produced by addictive substances, including ethanol. Here we evaluated synaptic activity in the dorsolateral striatum (DLS) and ventral striatum (nucleus accumbens, nAc) of single-housed Wistar rats consuming water, or water and ethanol, for up to 10 months. Even though ethanol intake was moderate, it was sufficient to decrease input/output function in response to stimulation intensity in the DLS, while recorded population spike (PS) amplitudes in the nAc were unaffected. Striatal disinhibition induced by the GABAA receptor antagonist bicuculline had a slower onset in rats that had consumed ethanol for 2 months, and was significantly depressed in slices from rats that had consumed ethanol for 4 months. Bicuculline-induced disinhibition in the nAc, on the other hand, was not significantly altered by long-term ethanol intake. Changes in PS amplitude induced by taurine or the glycine receptor antagonist strychnine were not significantly altered by ethanol in any brain region. Even though input/output function was not significantly affected by age, there was a significant decline in antagonist-induced disinhibition in brain slices from aged rats. The data presented here suggest that even modest consumption of ethanol is sufficient to alter neurotransmission in the striatum, while synaptic activity appears to be relatively well-preserved in the nAc during the course of long-term ethanol consumption.

Hippocampal CA1 region neurodegeneration produced by ethanol withdrawal requires activation of intrinsic polysynaptic hippocampal pathways and function of N-methyl- d-aspartate receptors

Long-term intake of ethanol produces adaptive alterations in multiple transmitter systems in the hippocampal formation that likely contribute to ethanol withdrawal-induced seizure and excitotoxicity. The present studies were designed to examine the role of N-methyl- d-aspartate receptor activation and cytosolic Ca 2+ accumulation in the neurotoxic effects of ethanol withdrawal. Further, these studies investigated the role of hippocampal network excitation in promoting both Ca 2+ accumulation and neurotoxicity during ethanol withdrawal. Chronic, continuous (11 day) exposure to ethanol (91 mM starting concentration) did not produce neurotoxicity in any region of organotypic hippocampal explants, as measured by uptake of the non-vital fluorescent marker propidium iodide. Withdrawal from chronic (10 day) ethanol exposure was associated with rapid (30 min) and significant increases in intracellular Ca 2+, assessed by visualization of Calcium-Orange fluorescence, in each region of hippocampal explants. However, neurotoxicity was observed 24 h after initiation of withdrawal and was only seen in the cornu ammonis 1 (CA1) region. Exposure to MK-801 (20 μM) at the start of ethanol withdrawal markedly attenuated Ca 2+ entry in all regions, as well as, CA1 region neurodegeneration. Further, treatment of explants with tetrodotoxin (500 nM) as well as surgical transection of mossy fiber or Schaffer collateral projections immediately prior to ethanol withdrawal blocked both regional increases in Ca 2+ accumulation and CA1 neurotoxicity. These data suggest that neurodegeneration observed during ethanol withdrawal is dependent upon polysynaptic propagation of action potentials (“network excitation”) and whole-hippocampal excitation of glutamatergic systems.