Repeated episodes of chronic intermittent ethanol promote insensitivity to devaluation of the reinforcing effect of ethanol

Studies in animal models have shown that repeated episodes of alcohol dependence and withdrawal promote escalation of drinking that is presumably associated with alterations in the addiction neurocircuitry. Using a lithium chloride-ethanol pairing procedure to devalue the reinforcing properties of ethanol, the present study determined whether multiple cycles of chronic intermittent ethanol (CIE) exposure by vapor inhalation also alters the sensitivity of drinking behavior to the devaluation of ethanol's reinforcing effects. The effect of devaluation on operant ethanol self-administration and extinction was examined in mice prior to initiation of CIE (short drinking history) and after repeated cycles of CIE or air control exposure (long drinking history). Devaluation significantly attenuated the recovery of baseline ethanol self-administration when tested either prior to CIE or in the air-exposed controls that had experienced repeated bouts of drinking but no CIE. In contrast, in mice that had undergone repeated cycles of CIE exposure that promoted escalation of ethanol drinking, self-administration was completely resistant to the effect of devaluation. Devaluation had no effect on the time course of extinction training in either pre-CIE or post-CIE mice. Taken together, these results are consistent with the suggestion that repeated cycles of ethanol dependence and withdrawal produce escalation of ethanol self-administration that is associated with a change in sensitivity to devaluation of the reinforcing properties of ethanol.     

Hepatoprotective effect of chitosan-caffeic acid conjugate against ethanol-treated mice

The chitosan-caffeic acid (CCA) conjugate shows a hepatoprotective effect against oxidative stress-induced hepatic damage in cultured hepatocytes. The objective of this study is the verification of the hepatoprotective effect of the CCA in vivo against ethanol-induced liver injury in mice. The administration of ethanol resulted in the increase of the serum-aminotransferase activities (AST and ALT), triglycerides, total cholesterol, and lipid peroxidation. The CCA co-administration, however, significantly (p < 0.05) ameliorated these serum biomarkers. The antioxidant-enzyme activities in the liver tissue, including those of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were significantly decreased by a chronic ethanol administration, whereas the hepatic lipid-peroxidation level was increased. Moreover, the chronic ethanol administration elevated the gene expression of pro-inflammatory cytokines such as tumor-necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the liver tissue. The CCA co-administration, however, significantly (p < 0.05) increased the activities of the SOD, CAT, and GPx and caused the down-regulation of the TNF-α- and IL-6-gene expressions in the liver tissue. An histopathologic evaluation also supported the hepatoprotective effect of the CCA against ethanol-induced hepatotoxicity in the mice.     

Ethanol withdrawal increases blood pressure and vascular oxidative stress: a role for angiotensin type 1 receptors

We evaluated the possible mechanisms underlying the oxidative stress induced by ethanol withdrawal. With this purpose, we verified the role of AT₁ receptors in such response. Male Wistar rats were treated with ethanol 3%–9% (vol./vol.) for 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 hours after ethanol discontinuation. Increased plasma levels of angiotensin II were detected after ethanol withdrawal. Losartan (10 mg/kg; p.o. gavage), a selective AT₁ receptor antagonist, impeded the increase in blood pressure induced by ethanol withdrawal. Increased lipoperoxidation and superoxide anion (O₂^?) levels were detected in aortas after ethanol withdrawal, and losartan prevented these responses. Decreased hydrogen peroxide and nitrate/nitrite concentration were detected in aortas after ethanol withdrawal, and losartan prevented these effects. Nitrotyrosine immunostaining in the rat aorta was increased after ethanol withdrawal, and AT₁ blockade impeded this response. Increased expression of PKCδ and p47^phox was detected after ethanol withdrawal, and treatment with losartan prevented these responses. Our study provides novel evidence that ethanol withdrawal increases vascular oxidative stress and blood pressure through AT₁-dependent mechanisms. These findings highlight the importance of angiotensin II in ethanol withdrawal–induced increase in blood pressure and vascular oxidative damage.     

全蝎醇提物与丙戊酸干预氯化锂-匹罗卡品慢性点燃模型大鼠癫痫发作的疗效比较

目的 探讨全蝎醇提物(Ethanol Extracts of Scorpion,EES)与丙戊酸(Valproic Acid,VPA)干预氯化锂一匹罗卡品(Lithium Chloride-Pilocarpine,Licl-Pilo)慢性点燃模型大鼠癫痫发作的疗效.方法 186只成年雄性大鼠除6只设为正常对照组外.其余均建立Licl-Pilo慢性点燃大鼠模型,遣模成功后分为模型组、VPA干预组、低 EES 剂量干预组(EESL干预组)、中EES剂量干预组(EESM干预组)和高EES剂量干预组(EESH干预组)各36只.正常对照组、模型组分别灌胃给予等容积的生理盐水,VPA干预组灌胃给予VPA溶液[浓度为120 ms/(kg·d)],EESL干预组、EESM干预组、EESH干预组灌胃给予EES溶液[浓度分别为290 ms/(kg·d)、580 nag/(kg·d)及1160 ms/(kg·d)],观察30天内致痫大鼠慢性癫痛自发性发作(spontaneous seizures,SRS)、发作级别、发作次数,并进行组问比较.结果 Licl-Pilo慢性点燃模型鼠的造模成功率为85.65%,各实验组SRS发生频率5～15次/周.治疗后,EESM干预组、EESH干预组和VPA干预组癫痫大鼠痫性发作级别及SRS发作次数与模型组比较差异有统计学意义(P<0.05);EESL干预组治疗效果不明显,与模型组比较差异无统计学意义(P>0.05).结论 一定剂量的EES能显著降低癫痫大鼠的自发性发作,且与疗效呈明显的量效关系,即剂量越大疗效越好,该结果 为EES的抗癫痫作用提供了行为学依据.     

Ethanol Untangles the Amygdala‐Anxiety Circuit Through Tonic GABA Inhibition

The central amygdala (CeA) has a unique role in integrating stress and the rewarding effects of ethanol (EtOH) and plays a major role in the development of EtOH dependence via signaling of corticotropin‐releasing factor (CRF). A recent report by Herman and colleagues (2013) entitled “Novel Subunit‐Specific Tonic GABA Currents and Differential Effects of Ethanol in the Central Amygdala of CRF Receptor‐1 Reporter Mice” is the first study to investigate inhibitory tonic currents in relation to CRF signaling in the CeA. The findings of that study significantly enhance our understanding of inhibitory tonic currents in the CeA and give insight into how EtOH may differentially affect CRF signaling within the CeA, leading to the development of EtOH dependence. This commentary will focus on the recent findings of Herman and colleagues and will discuss the effects of EtOH on the entire anxiety/emotion circuitry.     

Mass methanol poisonings in the Czech Republic

Abstract

The article provides detailed information on the case of 2012–2013 Czech mass methanol poisoning caused by the consumption of spirits with methanol added during manufacture. The article compares basic characteristics of methanol and ethanol. It also gives toxicological properties of methanol and describes therapy of methanol afflicted patients with the medicinal product Fomepizole. Having provided an overview of the short-term remedies to the Czech 2012–2013 poisoning problems, the authors suggest long-term measures for prevention of possible future mass poisoning cases like legislative changes and extension of school education with courses on ethanol and methanol effects in human organism.