BUTHIONINE SULFOXIMINE PROTECTS THE VIABILITY OF ADULT-RAT LEYDIG-CELLS EXPOSED TO ETHANE DIMETHANESULFONATE

Exposure to (EDS) in vivo or in vitro alters adult rat Leydig cell fun ction within 3 hr and these cells subsequently die within 24-48 hr. Pr eviously, we determined that reducing intracellular glutathione levels with buthionine sulfoximine (BSO) protects adult rat Leydig cell func tion during short-term (3 hr) EDS exposures. The present study extends these observations by assessing whether BSO also can prevent Leydig c ell death following EDS exposure. To assess whether BSO can prevent ED S-induced Leydig cell death, Leydig cells were cultured in the presenc e or the absence of 4 mM BSO (12 hr), and subsequently with increasing doses of EDS (3 hr). The effects of EDS on Leydig cell death were est imated using a cytotoxicity assay (MTT assay) and by assessing the abi lity of adult rat Leydig cells to maintain LH-stimulated testosterone production and [S-35]- methionine incorporation 24 hr following EDS ex posure. This culture duration was chosen because sustained alterations in MTT reduction, LH-stimulated testosterone production, and [S-35]me thionine incorporation 24 hr following EDS exposure were found to refl ect alterations in Leydig cell viability. The results suggest that low ering intracellular levels of glutathione with BSO prevents EDS-induce d Leydig cell death. Restoring intracellular levels of glutathione wit h glutathione ethyl ester (8 mM) in the presence of BSO also restored the ability of EDS to kill Leydig cells. Taken together, these data su ggest that glutathione mediates the mechanism by which EDS kills adult rat Leydig cells. (C) 1994 Academic Press, Inc.