ETHANOL AND MEMBRANE FUNCTION

乙醇和膜功能

• 批准号: 4687751
• 负责人: H C PANT
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON ALCOHOL ABUSE AND ALCOHOLISM
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/4687751
• 关键词: alcoholic beverage consumption; brain cell; dyes; ethanol; fluorescence polarization; growth media; membrane potentials; membrane reconstitution /synthesis; neuropharmacology; neurotoxins; synaptosomes; tissue /cell culture

Ethanol is known to alter the biochemical and biophysical properties of cellular membranes. In this investigation the mechanisms of ethanol-induced membrane potential changes in rat thymocytes were studied with fluorescence spectrophotometry using membrane potential-sensitive carbocyanine dyes. We analyzed (1) an ethanol-induced fluorescence increase (depolarization) in K-free saline-adapted cells, (2) a prolonged hyperpolarizing potential (fluorescence decrease) induced by adding small amounts of KC1 (1-5 mM) in K-+-free saline-adapted cells, and (3) a hyperpolarizing potential induced by the application of the Ca ionophore A23187 in normal saline. The ethanol-induced fluorescence increase in K-free saline solution was completely suppressed by the addition of a small amount of KC1 or the K ionophore valinomycin. Hyperpolarizing potentials induced by adding KC1 (1-15 mM) in K-free adapted cells were abolished by ouabain; this hyperpolarizing potential was not observed in the absence of Na in the bathing medium. These data indicate that the thymocytes possess a ouabain-sensitive electrogenic Na pump. The in vitro treatment of thymocytes with ethanol (200 mM) for up to 5 hours did not significantly alter this pump potential. However, in thymocytes derived from both ethanol-dependent intoxicated and ethanol-dependent withdrawing rats, the Na pump potential was significantly smaller than that observed in controls. The Ca-dependent hyperpolarization in response to A23187 (50 mM) was not significantly altered by the in vitro treatment of the cells with ethanol (200 mM) for 3 hours. These results suggest that ethanol can depolarize the membrane when the Na pump is inhibited by K-free saline and that alterations in Na pump activity may be associated with ethanol dependence.

已知乙醇会改变蛋白质的生物化学和生物物理性质， 细胞膜 在这项研究中， 本文研究了乙醇对大鼠胸腺细胞膜电位的影响 膜电位敏感荧光分光光度法 碳菁染料。 我们分析了（1）乙醇诱导的荧光 增加（去极化）在无钾盐适应细胞，（2）延长 超极化电位（荧光降低） 无K+盐适应细胞中的KCl量（1-5 mM），和（3）a 钙离子载体诱导的超极化电位 A23187的生理盐水溶液。 乙醇诱导的荧光增强 无钾盐溶液被完全抑制，通过添加少量 量的KCl或K离子载体缬氨霉素。 超极化电位 在无钾适应细胞中加入KCl（1-15 mM）诱导的细胞凋亡， 哇巴因;这种超极化电位在没有哇巴因的情况下没有观察到。 钠在洗澡介质。 这些数据表明胸腺细胞具有 哇巴因敏感的产电钠泵 体外治疗 胸腺细胞用乙醇（200 mM）处理长达5小时， 改变该泵电势。 然而，在来自两者的胸腺细胞中， 乙醇依赖性中毒和乙醇依赖性戒断大鼠， 钠泵电位明显小于在 对照 响应于A23187（50 mM）的Ca依赖性超极化 在体外处理细胞时， 乙醇（200 mM）中搅拌3小时。 这些结果表明，乙醇可以 当钠泵被无钾生理盐水抑制时， 钠泵活性的改变可能与乙醇 依赖