Nephrotoxicity of halogenated vinyl cysteine compounds

S-(1,2-dichlorovinyl) cysteine (DCVC), is a potent nephrotoxin. In order to determine if other vinyl cysteine conjugates were nephrotoxic, halogenated vinyl cysteines, HVC-1 and HVC-2, were prepared from chlorotrifluoroethylene (CTFE), a fluorocarbon monomer, or chlorodifluoroethylene, a metabolite of haltohane, respectively. Three days after receiving DCVC (5-10 mg/kg), CD-1 mice developed focal renal tubular necrosis. Mice treated with HVC-1 or HVC-2 (5-10 mg/kg) also developed renal necrosis by 3 days post exposure. HVC-1 was not as potent as DCVC with the necrosis limited to the pars recta. At equivalent doses HVC-2 caused less necrosis of the pars recta than HVC-1. The degree of nephrotoxicity by all three compounds exhibited a dose-response from 1-25 mg/kg. Doses greater than 25 mg/kg were often lethal within 3 days and the mice had a complete zonal necrosis of the renal cortex and a two-fold increase in kidney weight. Structural analogues, S-(chlorethyl) or S-(hydroxyethyl) cysteine, did not cause renal necrosis in mice at doses up to 200 mg/kg. These studies indicate that the enzymes reportedly responsible for converting DCVC to a nephrotoxic intermediate will also bioactivate other halogenated vinyl cysteines.