Lash L H, Anders M W
J Biol Chem. 1986 Oct 5;261(28):13076-81.
S-(1,2-Dichlorovinyl)glutathione (DCVG) and S-(1,2-dichlorovinyl)-L-cysteine (DCVC) produced time- and concentration-dependent cell death in isolated rat kidney proximal tubular cells. AT-125 blocked and glycylglycine potentiated DCVG toxicity, indicating that metabolism by gamma-glutamyltransferase is required. S-(1,2-Dichlorovinyl)-L-cysteinylglycine, a putative metabolite of DCVG, also produced cell death, which was prevented by 1,10-phenanthroline, phenylalanylglycine, and aminooxyacetic acid, inhibitors of aminopeptidase M, cysteinylglycine dipeptidase, and cysteine conjugate beta-lyase, respectively. Aminooxyacetic acid and probenecid protected against DCVC toxicity, indicating a role for metabolism by cysteine conjugate beta-lyase and organic anion transport, respectively. DCVC produced a small decrease in cellular glutathione concentrations and did not change cellular glutathione disulfide concentrations or initiate lipid peroxidation. DCVC caused a large decrease in cellular glutamate and ATP concentrations with a parallel decrease in the total adenine nucleotide pool; these changes were partially prevented by aminooxyacetic acid. Both DCVG and DCVC inhibited succinate-dependent oxygen consumption, but DCVC had no effect when glutamate + malate or ascorbate + N,N,N',N'-tetramethyl-p-phenylenediamine were the electron donors. DCVC inhibited mitochondrial, but not microsomal, Ca2+ sequestration. These alterations in mitochondrial function were partially prevented by inhibition of DCVG and DCVC metabolism and were strongly correlated with decreases in cell viability, indicating that mitochondria may be the primary targets of nephrotoxic cysteine S-conjugates.
S-(1,2-二氯乙烯基)谷胱甘肽(DCVG)和S-(1,2-二氯乙烯基)-L-半胱氨酸(DCVC)在分离的大鼠肾近端小管细胞中产生时间和浓度依赖性细胞死亡。AT-125可阻断DCVG毒性，而甘氨酰甘氨酸可增强其毒性，这表明需要γ-谷氨酰转移酶进行代谢。DCVG的一种假定代谢产物S-(1,2-二氯乙烯基)-L-半胱氨酰甘氨酸也可导致细胞死亡，而1,10-菲咯啉、苯丙氨酰甘氨酸和氨氧基乙酸分别作为氨肽酶M、半胱氨酰甘氨酸二肽酶和半胱氨酸共轭β-裂解酶的抑制剂可阻止这种情况发生。氨氧基乙酸和丙磺舒可保护细胞免受DCVC毒性影响，分别表明半胱氨酸共轭β-裂解酶代谢和有机阴离子转运的作用。DCVC使细胞内谷胱甘肽浓度略有下降，但未改变细胞内谷胱甘肽二硫化物浓度，也未引发脂质过氧化。DCVC导致细胞内谷氨酸和ATP浓度大幅下降，同时总腺嘌呤核苷酸池也平行下降；氨氧基乙酸可部分阻止这些变化。DCVG和DCVC均抑制琥珀酸依赖性氧消耗，但当谷氨酸+苹果酸或抗坏血酸+N,N,N',N'-四甲基对苯二胺作为电子供体时，DCVC没有作用。DCVC抑制线粒体而非微粒体对Ca2+的摄取。这些线粒体功能的改变可通过抑制DCVG和DCVC代谢而部分得到预防，并且与细胞活力的下降密切相关，表明线粒体可能是肾毒性半胱氨酸S-共轭物的主要靶点。
