Wallin A, Jones T W, Vercesi A E, Cotgreave I, Ormstad K, Orrenius S
Department of Forensic Medicine, Karolinska Institute, Stockholm, Sweden.
Arch Biochem Biophys. 1987 Nov 1;258(2):365-72. doi: 10.1016/0003-9861(87)90357-2.
The subcellular mechanism of alkenyl halide S-conjugate-induced nephrotoxicity was studied in mitochondria isolated from rat kidney cortex in vitro using the cysteine conjugate of hexachloro-1,3-butadiene, i.e., S-pentachlorobutadienyl-L-cysteine (PCBC) as a model substrate. Respiring mitochondria exposed to various concentrations of PCBC exhibited a dose-dependent loss of ability to retain calcium. This phenomenon was associated with a sudden collapse of the mitochondrial membrane potential. PCBC caused a slow nonenzymatic depletion of mitochondrial glutathione. This was not due to oxidation or formation of mixed disulfides, and was efficiently counteracted by preincubation with aminooxyacetic acid, an inhibitor of cysteine-conjugate beta-lyase activity. PCBC inhibited state 3 respiration in the presence of succinate as substrate, which indicates that the activity of succinate dehydrogenase was affected. Thus, the present data confirm that impairment of mitochondrial function is a feature of nephrotoxicity mediated by alkenyl halide S-conjugates. We suggest a pathway involving interaction of beta-lyase-dependent reactive metabolite with the mitochondrial inner membrane, loss of membrane potential, disturbance of Ca2+ homeostasis, and subsequent respiratory insufficiency as a mechanism for renal tubular cytotoxicity.
使用六氯 - 1,3 - 丁二烯的半胱氨酸结合物，即S - 五氯丁二烯基 - L - 半胱氨酸（PCBC）作为模型底物，在体外从大鼠肾皮质分离的线粒体中研究了卤代烯烃S - 结合物诱导的肾毒性的亚细胞机制。暴露于不同浓度PCBC的呼吸线粒体表现出剂量依赖性的钙保留能力丧失。这种现象与线粒体膜电位的突然崩溃有关。PCBC导致线粒体谷胱甘肽的缓慢非酶消耗。这不是由于氧化或混合二硫化物的形成，并且通过用半胱氨酸结合物β - 裂解酶活性抑制剂氨基氧基乙酸预孵育而得到有效抵消。在以琥珀酸为底物的情况下，PCBC抑制状态3呼吸，这表明琥珀酸脱氢酶的活性受到影响。因此，目前的数据证实线粒体功能受损是卤代烯烃S - 结合物介导的肾毒性的一个特征。我们提出了一条途径，涉及β - 裂解酶依赖性反应性代谢物与线粒体内膜的相互作用、膜电位丧失、Ca2 + 稳态紊乱以及随后的呼吸功能不全，作为肾小管细胞毒性的一种机制。
