S-(1,2-rmDichlorovinyl)glutathione and are potent nephrotoxins. Agents that inhibit γ-glutamyl transpeptidase, cysteine conjugate β-lyase, and renal organic anion transport systems, namely acid (AT-125), aminooxyacetic acid, and probenecid, respectively, protected against S-conjugate-induced nephrotoxicity. Furthermore, , which cannot be cleaved by cysteine conjugate β-lyase, was not nephrotoxic. These results strongly support a role for renal γ-glutamyl transpeptidase, cysteine conjugate β-lyase, and organic anion transport systems in S-(1,2-dichlorovinyl)glutathione- and S-(1,2,-dichlorovinyl)cysteine-induced nephrotoxicity.