N-(3,5-Dichlorophenyl)succinimide (NDPS) is an agricultural fungicide which induces acute tubular necrosis as its primary toxicity. Two NDPS metabolites, N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS) and N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (NDHSA) previously have been shown to be more potent nephrotoxicants than NDPS. In addition, buthionine sulfoximine (BSO), a glutathione synthesis inhibitor, was found to attenuate NDPS-induced nephrotoxicity. The purpose of this study was to examine the effects of BSO pretreatment on NDHS- and NDHSA-induced nephrotoxicity. Male Fischer-344 rats (4 rats/group) were administered intraperitoneally (i.p.) BSO (890 mg/kg) 2 h before NDHS or NDHSA (0.1 or 0.2 mmol/kg, i.p.) or vehicle (sesame oil, 2.5 ml/kg), and renal function monitored at 24-h intervals for 48 h. BSO pretreatment markedly attenuated NDHSA (0.1 or 0.2 mmol/kg)-induced effects on the renal functional parameters monitored. BSO pretreatment also markedly reduced NDHS (0.1 mmol/kg)-induced renal effects. However, NDHS (0.2 mmol/kg) nephrotoxicity was attenuated to a lesser extent than NDHS (0.1 mmol/kg) nephropathy. These results indicate that glutathione is an important mediator of NDPS metabolite nephrotoxicity and suggests that BSO did not attenuate NDPS nephropathy by inhibiting NDPS biotransformation to NDHS or NDHSA.