Chronic Ethanol Consumption Alters All-Trans-Retinoic Acid Concentration and Expression of Their Receptors on the Prostate: A Possible Link Between Alcoholism and Prostate Damage

Background: Ethanol (EtOH) alters the all-trans-retinoic acid (ATRA) levels in some tissues. Retinol and ATRA are essential for cell proliferation, differentiation, and maintenance of prostate homeostasis. It has been suggested that disturbances in retinol/ATRA concentration as well as in the expression of retinoic acid receptors (RARs) contribute to benign prostate hyperplasia and prostate cancer. This study aimed to evaluate whether EtOH consumption is able to alter retinol and ATRA levels in the plasma and prostate tissue as well as the expression of RARs, cell proliferation, and apoptosis index. Methods: All animals were divided into 4 groups (n = 10/group). UChA: rats fed 10% (v/v) EtOH ad libitum; UChACo: EtOH-naïve rats without access to EtOH; UChB: rats fed 10% (v/v) EtOH ad libitum; UChBCo: EtOH-naïve rats without access to EtOH. Animals were euthanized by decapitation after 60 days of EtOH consumption for high-performance liquid chromatography and light microscopy analysis. Results: EtOH reduced plasma retinol concentration in both UChA and UChB groups, while the retinol concentration was not significantly different in prostate tissue. Conversely, plasma and prostate ATRA levels increased in UChB group compared with controls, beyond the up-regulation of RARβ and -γ in dorsal prostate lobe. Additionally, no alteration was found in cell proliferation and apoptosis index involving dorsal and lateral prostate lobe. Conclusions: We conclude that EtOH alters the plasma retinol concentrations proportionally to the amount of EtOH consumed. Moreover, high EtOH consumption increases the concentration of ATRA in plasma/prostate tissue and especially induces the RARβ and RARγ in the dorsal prostate lobe. EtOH consumption and increased ATRA levels were not associated with cell proliferation and apoptosis in the prostate. © 2012 by the Research Society on Alcoholism.

Time-course of neuroendocrine changes and its correlation with hypertension induced by ethanol consumption

Ethanol (ETOH) consumption has been associated with endocrine and autonomic changes, including the development of hypertension. However, the sequence of pathophysiological events underlying the emergence of this effect is poorly understood. Aims: This study aimed to establish a time-course correlation between neuroendocrine and cardiovascular changes contributing to the development of hypertension following ETOH consumption. Methods: Male adult Wistar rats were subjected to the intake of increasing ETOH concentrations in their drinking water (first week: 5%, second week: 10%, third and fourth weeks: 20% v/v). Results: ETOH consumption decreased plasma and urinary volumes, as well as body weight and fluid intake. Furthermore, plasma osmolality, plasma sodium and urinary osmolality were elevated in the ETOH-treated rats. ETOH intake also induced a progressive increase in the mean arterial pressure (MAP), without affecting heart rate. Initially, this increasein MAP was correlated with increased plasma concentrations of adrenaline and noradrenaline. After the second week of ETOH treatment, plasma catecholamines returned to basal levels, and incremental increases were observed in plasma concentrations of vasopressin (AVP) and angiotensin II (ANG II). Conversely, plasma oxytocin, atrial natriuretic peptide, prolactin and the hypothalamus-pituitary-adrenal axis components were not significantly altered by ETOH. Conclusions: Taken together, these results suggest that increased sympathetic activity may contribute to the early increase in MAP observed inETOHtreated rats. However, the maintenance of this effect may be predominantly regulated by the long-term increase in the secretion of other circulating factors, such as AVP and ANG II, the secretion of both hormones being stimulated by the ETOH-induced dehydration. © The Author 2013. Medical Council on Alcohol and Oxford University Press. All rights reserved.

Stress Abolishes the Effect of Previous Chronic Ethanol Consumption on Drug Place Preference and on the Mesocorticolimbic Brain Pathway

BackgroundConditioned place preference (CPP) to ethanol (EtOH) is an important addiction-related alteration thought to be mediated by changed neurotransmission in the mesocorticolimbic brain pathway. Stress is a factor of major importance for the initiation, maintenance, and reinstatement of drug abuse and modulates the neurochemical outcomes of drugs. Thus, the aim of this study was to investigate the effects of concomitant exposure to chronic EtOH and stress on CPP to this drug and alterations of dopaminergic and serotonergic neurotransmission in mice.MethodsMale Swiss mice were chronically treated with EtOH via a liquid diet and were exposed to forced swimming stress. After treatment, animals were evaluated for conditioning, extinction, and reinstatement of CPP to EtOH. Also, mice exposed to the same treatment protocol had their prefrontal cortex (PFC), nucleus accumbens (NAc), and amygdala dissected for the quantitation of dopamine, serotonin, and their metabolites content.ResultsData showed that previous chronic exposure to EtOH potentiated EtOH conditioning and increased dopaminergic turnover in PFC. Exposure to stress potentiated EtOH conditioning and decreased dopaminergic turnover in the NAc. However, animals exposed to both chronic EtOH and stress did not display alterations of CPP and showed an elevated content of dopamine in amygdala. No treatment yielded serotonergic changes.ConclusionsThe present study indicates that previous EtOH consumption as well as stress exposure induces increased EtOH conditioning, which can be related to dopaminergic alterations in the PFC or NAc. Interestingly, concomitant exposure to both stimuli abolished each other's effect on conditioning and PFC or NAc alterations. This protective outcome can be related to the dopaminergic increase in the amygdala.

Cardiovascular alterations at different stages of hypertension development during ethanol consumption: Time-course of vascular and autonomic changes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Testosterone Therapy Differently Regulates the Anti- and Pro-Inflammatory Cytokines in the Plasma and Prostate of Rats Submitted to Chronic Ethanol Consumption (UChB)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Endothelial AT(1) and AT(2) pathways in aortic responses to angiotensin II after stress and ethanol consumption in rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Rutin ameliorates glycemic index, lipid profile and enzymatic activities in serum, heart and liver tissues of rats fed with a combination of hypercaloric diet and chronic ethanol consumption

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Androgen therapy reverses injuries caused by ethanol consumption in the prostate: testosterone as a possible target to ethanol-related disorders

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ethanol consumption enhances periodontal inflammatory markers in rats

Objective: The aim of this study was to assess the short term effect of ethanol administration on periodontal disease in rats. Design: Rats received either ethanol 2 g/kg or water by gastric gavage twice a day. On the fifth day ligatures were tied around the molars of half of the rats to induce periodontitis. After 7 days gingival tissue was removed and assayed for inflammatory markers. Finally, hemi-mandibles were extracted to evaluate bone loss by histomorphometrical techniques. Results: The experimental periodontitis increased significantly the mRNA expression (p < 0.001) and activity (p < 0.001) of inducible nitric oxide synthase (iNOS) in the gingival tissue, whilst short time ethanol administration increased iNOS activity (p < 0.05) and produced an additive effect on iNOS mRNA expression augmented by periodontitis (p < 0.01). The short time ethanol administration also potentiated the periodontitis stimulatory effect on the mRNA expression of interleukin (IL)-1 beta (p < 0.01 and p < 0.001, in semi-quantitative and real time PCR, respectively) and on the height of periodontal ligament (p < 0.05). However, the ligature-induced periodontitis, but not ethanol administration, increased the prostaglandin E-2 content (p < 0.05) and, diminished the alveolar bone volume (p < 0.05), as compared to sham rats. Conclusion: The present results suggest that ethanol consumption could represent a risk indicator for periodontal disease since augments the expression of inflammatory markers, in healthy rats, and increases them, at short term, during the illness. However, scale longitudinal investigation and more case-control studies are needed to confirm this statement. (C) 2012 Elsevier Ltd. All rights reserved.

Ethanol Consumption Alters the Expression and Reactivity of Adrenomedullin in the Rat Mesenteric Arterial Bed

Aims: Adrenomedullin (AM) is a peptide that displays cardiovascular protective activity. We investigated the effects of chronic ethanol consumption on arterial blood pressure, vascular reactivity to AM and the expression of AM system components in the rat mesenteric arterial bed (MAB). Methods: Male Wistar rats were treated with ethanol (20% vol/vol) for 6 weeks. Systolic, diastolic and mean arterial blood pressure were monitored in conscious rats. Vascular reactivity experiments were performed on isolated rat MAB. Matrix metalloproteinase-2 (MMP-2) levels were determined by gelatin zymography. Nitrite and nitrate generation were measured by chemiluminescence. Protein and mRNA levels of pre-pro-AM, CRLR (calcitonin receptor-like receptor) and RAMP1, 2 and 3 (receptor activity-modifying proteins) were assessed by western blot and quantitative real-time polymerase chain reaction, respectively. Results: Ethanol consumption induced hypertension and decreased the relaxation induced by AM and acetylcholine in endothelium-intact rat MAB. Phenylephrine-induced contraction was increased in endothelium-intact MAB from ethanol-treated rats. Ethanol consumption did not alter basal levels of nitrate and nitrite, nor did it affect the expression of MMP-2 or the net MMP activity in the rat MAB. Ethanol consumption increased mRNA levels of pre-pro-AM and protein levels of AM in the rat MAB. Finally, no differences in protein levels or mRNA of CRLR and RAMP1, 2 and 3 were observed after treatment with ethanol. Conclusion: Our study demonstrates that ethanol consumption increases blood pressure and the expression of AM in the vasculature and reduces the relaxation induced by this peptide in the rat MAB.

Ethanol consumption increases the expression of endothelial nitric oxide synthase, inducible nitric oxide synthase and metalloproteinases in the rat kidney

Objectives The effects of longterm ethanol consumption on the levels of nitric oxide (NO) and the expression of endothelial NO synthase (eNOS), inducible NO synthase (iNOS) and metalloproteinase-2 (MMP-2) were studied in rat kidney. Methods Male Wistar rats were treated with 20% ethanol (v/v) for 6 weeks. Nitrite and nitrate generation was measured by chemiluminescence. Protein and mRNA levels of eNOS and iNOS were assessed by immunohistochemistry and quantitative real-time polymerase chain reaction, respectively. MMP-2 activity was determined by gelatin zymography. Histopathological changes in kidneys and indices of renal function (creatinine and urea) and tissue injury (mitochondrial respiration) were also investigated. Results Chronic ethanol consumption did not alter malondialdehyde levels in the kidney. Ethanol consumption induced a significant increase in renal nitrite and nitrate levels. Treatment with ethanol increased mRNA expression of both eNOS and iNOS. Immunohistochemical assays showed increased immunostaining for eNOS and iNOS after treatment with ethanol. Kidneys from ethanol-treated rats showed increased activity of MMP-2. Histopathological investigation of kidneys from ethanol-treated animals revealed tubular necrosis. Indices of renal function and tissue injury were not altered in ethanol-treated rats. Conclusions Ethanol consumption increased renal metalloproteinase expression/activity, which was accompanied by histopathological changes in the kidney and elevated NO generation. Since iNOS-derived NO and MMPs contribute to progressive renal injury, the increased levels of NO and MMPs observed in ethanol-treated rats might contribute to progressive renal damage.

Ethyl sulphate and ethyl glucuronide in vitreous humor as postmortem evidence marker for ethanol consumption prior to death

To clarify the circumstances of death, the degree of inebriation is of importance in many cases, but for several reasons the determination of the ethanol concentration in post-mortem samples can be challenging and the synopsis of ethanol and the direct consumption markers ethyl glucuronide (EtG) and ethyl sulphate (EtS) has proved to be useful. The use of a rather stable matrix like vitreous humor offers further advantages. The aim of this study was to determine the concentrations of ethanol and the biomarkers in the robust matrix of vitreous humor and to compare them with the respective levels in peripheral venous blood and urine. Samples of urine, blood from the femoral vein and vitreous humor were taken from 26 deceased with suspected ethanol consumption prior to death and analyzed for ethanol, EtS and EtG. In the urine samples creatinine was also determined. The personal data, the circumstances of death, the post-mortem interval and the information about ethanol consumption prior to death were recorded. EtG and EtS analysis in urine was performed by LC-ESI-MS/MS, creatinine concentration was determined using the Jaffé reaction and ethanol was detected by HS-GC-FID and by an ADH-based method. In general, the highest concentrations of the analytes were found in urine and showed statistical significance. The mean concentrations of EtG were 62.8mg/L (EtG100 206.5mg/L) in urine, 4.3mg/L in blood and 2.1mg/L in vitreous humor. EtS was found in the following mean concentrations: 54.6mg/L in urine (EtS100 123.1mg/L), 1.8mg/L in blood and 0.9mg/L in vitreous humor. Ethanol was detected in more vitreous humor samples (mean concentration 2.0g/kg) than in blood and urine (mean concentration 1.6g/kg and 2.1g/kg respectively). There was no correlation between the ethanol and the marker concentrations and no statistical conclusions could be drawn between the markers and matrices.

Daidzin suppresses ethanol consumption by Syrian golden hamsters without blocking acetaldehyde metabolism.

Daidzin is a potent, selective, and reversible inhibitor of human mitochondrial aldehyde dehydrogenase (ALDH) that suppresses free-choice ethanol intake by Syrian golden hamsters. Other ALDH inhibitors, such as disulfiram (Antabuse) and calcium citrate carbimide (Temposil), have also been shown to suppress ethanol intake of laboratory animals and are thought to act by inhibiting the metabolism of acetaldehyde produced from ingested ethanol. To determine whether or not daidzin inhibits acetaldehyde metabolism in vivo, plasma acetaldehyde in daidzin-treated hamsters was measured after the administration of a test dose of ethanol. Daidzin treatment (150 mg/kg per day i.p. for 6 days) significantly suppresses (> 70%) hamster ethanol intake but does not affect overall acetaldehyde metabolism. In contrast, after administration of the same ethanol dose, plasma acetaldehyde concentration in disulfiram-treated hamsters reaches 0.9 mM, 70 times higher than that of the control. In vitro, daidzin suppresses hamster liver mitochondria-catalyzed acetaldehyde oxidation very potently with an IC50 value of 0.4 microM, which is substantially lower than the daidzin concentration (70 microM) found in the liver mitochondria of daidzin-treated hamsters. These results indicate that (i) the action of daidzin differs from that proposed for the classic, broad-acting ALDH inhibitors (e.g., disulfiram), and (ii) the daidzin-sensitive mitochondrial ALDH is not the one and only enzyme that is essential for acetaldehyde metabolism in golden hamsters.

The α5 neuronal nicotinic acetylcholine receptor subunits plays an important role in the sedative effects of ethanol but does not modulate consumption in mice

Alcohol use disorders (AUDs) are a major public health problem, and the few treatment options available to those seeking treatment offer only modest success rates. There remains a need to identify novel targets for the treatment of AUDs. The neuronal nicotinic acetylcholine receptors (nAChRs) represent a potential therapeutic target in the brain, as recent human genetic studies have implicated gene variants in the α5 nAChR subunit as high risk factors for developing alcohol dependence. Here, we evaluate the role of 5* nAChR for ethanol-mediated behaviors using α5+/+ and α5-/- mice. We characterized the effect of hypnotic doses of ethanol and investigated drinking behavior using an adapted Drinking-in-the Dark (DID) paradigm that has been shown to induce high ethanol consumption in mice. We found the α5 subunit to be critical in mediating the sedative effects of ethanol. The α5-/- mice showed slower recovery from ethanol-induced sleep, as measured by loss of righting reflex. Additionally the α5-/- mice showed enhanced impairment to ethanol-induced ataxia. We found the initial sensitivity to ethanol and ethanol metabolism to be similar in both α5+/+ and α5-/- mice. Hence the enhanced sedation is likely due to a difference in the acute tolerance of ethanol in mice deficient of the α5 subunit. However the α5 subunit did not play a role in ethanol consumption for ethanol concentrations ranging from 5% to 30% in the DID paradigm. Additionally, varenicline (Chantix®) was effective in reducing ethanol intake in α5-/- mice. Together, our data suggest that the α5 nAChR subunit is important for the sedative hypnotic doses of ethanol but does not play a role in ethanol consumption. Varenicline can be a treatment option even when there is loss of function of the α5 nAChR subunit.

The neurokinin 1 receptor antagonist, ezlopitant, reduces appetitive responding for sucrose and ethanol

Abstract Background: The current obesity epidemic is thought to be partly driven by over-consumption of sugar-sweetened diets and soft drinks. Loss-of-control over eating and addiction to drugs of abuse share overlapping brain mechanisms including changes in motivational drive, such that stimuli that are often no longer ‘liked’ are still intensely ‘wanted’ [7,8]. The neurokinin 1 (NK1) receptor system has been implicated in both learned appetitive behaviors and addiction to alcohol and opioids; however, its role in natural reward seeking remains unknown. Methodology/Principal Findings: We sought to determine whether the NK1-receptor system plays a role in the reinforcing properties of sucrose using a novel selective and clinically safe NK1-receptor antagonist, ezlopitant (CJ-11,974), in three animal models of sucrose consumption and seeking. Furthermore, we compared the effect of ezlopitant on ethanol consumption and seeking in rodents. The NK1-receptor antagonist, ezlopitant decreased appetitive responding for sucrose more potently than for ethanol using an operant self-administration protocol without affecting general locomotor activity. To further evaluate the selectivity of the NK1-receptor antagonist in decreasing consumption of sweetened solutions, we compared the effects of ezlopitant on water, saccharin-, and sodium chloride (NaCl) solution consumption. Ezlopitant decreased intake of saccharin but had no effect on water or salty solution consumption. Conclusions/Significance: The present study indicates that the NK1-receptor may be a part of a common pathway regulating the self-administration, motivational and reinforcing aspects of sweetened solutions, regardless of caloric value, and those of substances of abuse. Additionally, these results indicate that the NK1-receptor system may serve as a therapeutic target for obesity induced by over-consumption of natural reinforcers.