Role of Tissue Repair in Survival from S-(1,2-Dichlorovinyl)-L-Cysteine– Induced Acute Renal Tubular Necrosis in the Mouse

S-(1,2-Dichlorovinyl)-L-cysteine (DCVC), a model nephrotoxi-cant in mice, causes acute tubular necrosis and death at high doses. Our earlier studies revealed that renal tissue repair was critical for survival in mice with DCVC nephrotoxicity. The ob-jective of this study was to investigate if increasing renal tissue repair could protect mice from the lethal outcome of DCVC. Male Swiss Webster (SW) mice were administered a low dose of DCVC (15 mg/kg, ip) 72 h before injection of a normally lethal dose of DCVC (75 mg/kg, ip); this resulted in 100 % protection against the lethal effect of DCVC. Because DCVC caused twofold decrease in cytosolic and mitochondrial -lyase activity, the possibility that DCVC protection may be caused by decreased bioactivation was examined. Mercuric chloride (HgCl2, 6 mg/kg), a nephrotoxicant with no effect on -lyase activity, was administered 96 h before a lethal dose of DCVC. This also resulted in 100 % protection from the lethal effect of DCVC. In both studies total glutathione was unchanged at any time after the lethal dose of DCVC was admin-istered, obviating the role of glutathione in protection. In both cases the augmented and sustained tissue repair induced by prim-ing dose and documented by 3H-thymidine pulse labeling and immunocytochemistry for proliferating cell nuclear antigen re-sulted in 100 % survival in spite of the extensive renal injury. These findings suggest that stimulation of renal tubular repair by the priming dose, through augmented cell division, and the resistance of new cells to mechanisms of progression of injury, underlies auto- and heteroprotection against DCVC. The molecular mech-anisms may have potential application in pharmacotherapeutic intervention for treatment of acute renal failure