IN-VITRO EFFECTS OF CELIPTIUM AND MR-14504 ON MATURE RAT LEYDIG-CELL TESTOSTERONE PRODUCTION

Percoll-purified mature rat Leydig cells have been used to evaluate th e testicular toxicity of two highly potent intercalating agents (Celip tium and MR 14505). Testosterone secretion in the absence and in the p resence of human chorionic gonadotropin (hCG) was measured to assess L eydig cell function. Celiptium and MR 14504 induce time- and dose-rela ted inhibitory effects on the production of testosterone by Leydig cel ls, both in the presence and in the absence of hCG, whatever the conce ntration of hCG used. We have observed that MR 14504 is about 5 times more potent as an inhibitor of rat Leydig cell steroidogenesis than Ce liptium without inducing any cell toxicity. The present study indicate s that the Leydig cell is an additional potential site for the primary toxic effects of these drugs in the adult rat testis.