ETHANOL AND MEMBRANE FUNCTION

众所周知，乙醇可以改变生物化学和生物物理。 细胞膜的性质。在这次调查中， 乙醇诱导心肌细胞膜电位变化的机制 脑突触体和大鼠胸腺细胞的研究 膜电位-荧光分光光度法 敏感染料。乙醇对心肌细胞膜电位的影响 用罗丹明6G荧光分光光度法研究突触小体。这个 荧光信号对产生的退偏振响应 突触体外K+浓度升高。这个 从5 mm开始，荧光强度随(K+)O的增加而增加 至60 mm，然后在较高浓度下趋于平稳。当 (Na+)O浓度从0变化到137 mM，保持 (K+)O常数为5 mM时，荧光没有变化。 加入乙醇后，荧光强度增强。 荧光强度有显著变化(15%) 用低至10毫米乙醇。荧光强度增加 乙醇浓度在10~100 mM范围内变化。乙醇 对去极化的(80 MM Kc1)突触小体无作用。这个 乙醇对膜去极化的影响与K+相似 去极化。在没有突触体的情况下，乙醇没有 对染料荧光强度的影响。在裂解或12小时内。年长的 突触体的荧光也没有变化。 (K+)O或乙醇。我们得出结论：(1)罗丹明6G 荧光可以用来监测细胞膜的变化 突触体的潜力(2)低剂量乙醇产生 大鼠分离突触体膜电位的变化 大脑。

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 brain synaptosomes and rat thymocytes were studied with fluorescence spectrophotometry using membrane potential- sensitive dyes. The effect of ethanol on membrane potential in synaptosomes was studied using rhodamine 6G fluoroscence. The fluorescence signal responds to the depolarization produced by increasing concentration of K+ outside the synaptosomes. The fluorescence intensity increases with increasing (K+)O from 5 mM to 60 mM and then levels off at higher concentrations. When the (Na+)O concentration was changed from 0 to 137 mM, keeping (K+)O constant at 5 mM, no change is observed in fluorescence. On addition of ethanol, the fluorescence intensity increased. There was a significant change (15%) in fluorescence intensity with as low 10 mM ethanol. The fluorescence intensity increase as ethanol concentration was varied from 10 to 100 mM. Ethanol had no effect of depolarized (80 mM KC1) synaptosomes. The effect of ethanol on membrane depolarization was similar to K+ depolarization. In the absence of synaptosomes ethanol had no effect in the fluorescence intensity of dye. In lysed or 12 hr. old synaptosomes, there was no change in fluorescence either with (K+)O or ethanol. We concluded that (1) Rhodamine 6G fluorescence can be used to monitor the change in membrane potential in synaptosomes (2) low doses of ethanol produces changes in membrane potential in synaptosomes isolated from rat brain.