Lash L H, Woods E B
Department of Pharmacology, Wayne State University, School of Medicine, Detroit, Michigan 48201.
Arch Biochem Biophys. 1991 Apr;286(1):46-56. doi: 10.1016/0003-9861(91)90007-6.
Patterns of chemical-induced cytotoxicity in different regions of the nephron were studied with freshly isolated proximal tubular and distal tubular cells from rat kidney. Three model alkylating agents, methyl vinyl ketone, allyl alcohol, and N-dimethylnitrosamine, were used as test chemicals. Methyl vinyl ketone and a metabolite of allyl alcohol, acrolein, are Michael acceptors that bind to cellular protein sulfhydryl groups and GSH. N-Dimethylnitrosamine binds to cellular protein and DNA. Lactate dehydrogenase leakage was used to assess irreversible cellular injury. Distal tubular cells were more susceptible than proximal tubular cells to injury produced by methyl vinyl ketone or allyl alcohol while the two cell populations were equally susceptible to injury produced by N-dimethylnitrosamine. Preincubation of both proximal tubular and distal tubular cells with GSH protected them from methyl vinyl ketone- and allyl alcohol-induced cytotoxicity but had no effect on N-dimethylnitrosamine-induced cytotoxicity. Similarly, incubation of cells with methyl vinyl ketone or allyl alcohol, but not N-dimethylnitrosamine, altered cellular GSH status. As with GSH status, incubation of cells with methyl vinyl ketone or allyl alcohol, but not N-dimethylnitrosamine, caused pronounced inhibitory effects on mitochondrial function, as evidenced by ATP depletion and inhibition of cellular oxygen consumption. These results demonstrate that alkylating agents are cytotoxic to both proximal tubular and distal tubular cells, and that interaction with cellular GSH is a factor determining nephron cell type specificity of injury.
利用从大鼠肾脏新鲜分离的近端肾小管细胞和远端肾小管细胞，研究了化学物质诱导的肾单位不同区域细胞毒性的模式。三种模型烷基化剂，即甲基乙烯基酮、烯丙醇和N-二甲基亚硝胺，用作测试化学品。甲基乙烯基酮和烯丙醇的一种代谢产物丙烯醛是迈克尔受体，它们与细胞蛋白质巯基和谷胱甘肽（GSH）结合。N-二甲基亚硝胺与细胞蛋白质和DNA结合。乳酸脱氢酶泄漏用于评估不可逆的细胞损伤。远端肾小管细胞比近端肾小管细胞对甲基乙烯基酮或烯丙醇所致损伤更敏感，而这两种细胞群体对N-二甲基亚硝胺所致损伤的敏感性相同。近端肾小管细胞和远端肾小管细胞与GSH预孵育可使其免受甲基乙烯基酮和烯丙醇诱导的细胞毒性，但对N-二甲基亚硝胺诱导的细胞毒性没有影响。同样，细胞与甲基乙烯基酮或烯丙醇孵育（而非与N-二甲基亚硝胺孵育）会改变细胞的GSH状态。与GSH状态一样，细胞与甲基乙烯基酮或烯丙醇孵育（而非与N-二甲基亚硝胺孵育）会对线粒体功能产生明显的抑制作用，这表现为ATP耗竭和细胞氧消耗受到抑制。这些结果表明，烷基化剂对近端肾小管细胞和远端肾小管细胞均具有细胞毒性，并且与细胞GSH的相互作用是决定肾单位细胞类型损伤特异性的一个因素。
