Speisky H, Kera Y, Penttilä K E, Israel Y, Lindros K O
Department of Pharmacology, University of Toronto, Ontario, Canada.
Alcohol Clin Exp Res. 1988 Apr;12(2):224-8. doi: 10.1111/j.1530-0277.1988.tb00184.x.
The mechanism of ethanol-induced depletion of hepatic glutathione (GSH) was studied in vivo and in isolated hepatocytes. Neither inhibition of ethanol metabolism with 4-methylpyrazole, nor a 10-fold elevation of acetaldehyde levels by inhibition of aldehyde dehydrogenase with cyanamide or disulfiram, affected the magnitude of the GSH depletion observed in vivo. The rate of intracellular GSH accumulation by isolated hepatocytes incubated with cysteine or methionine was not inhibited by the addition of 80 mM ethanol. A significantly decreased rate of GSH accumulation was, however, found in hepatocytes isolated from ethanol-intoxicated animals. Neither the in vivo pretreatment with ethanol nor its in vitro addition to isolated hepatocytes affected the rate of GSH efflux. The results suggest that ethanol itself, rather than its metabolic products, causes depletion of liver GSH, and that events occurring in vivo are required for such an effect to be exerted.
在体内和分离的肝细胞中研究了乙醇诱导的肝谷胱甘肽(GSH)耗竭的机制。用4-甲基吡唑抑制乙醇代谢,或用氨甲环酸或双硫仑抑制醛脱氢酶使乙醛水平升高10倍,均不影响体内观察到的GSH耗竭程度。用半胱氨酸或蛋氨酸孵育的分离肝细胞中细胞内GSH积累速率不受添加80 mM乙醇的抑制。然而,在从乙醇中毒动物分离的肝细胞中发现GSH积累速率显著降低。乙醇的体内预处理及其在体外添加到分离的肝细胞中均不影响GSH外排速率。结果表明,乙醇本身而非其代谢产物导致肝脏GSH耗竭,并且这种作用的发挥需要体内发生的事件。