Inhibition of 3 beta-hydroxy-delta 5-steroid dehydrogenase in rat testicular tissue by mercuric chloride.

Histochemical investigations of 3 beta-hydroxy-delta 5-steroid dehydrogenase (delta 5-3 beta OHD) activity in the testicular tissue of rats administered mercuric chloride (HgCl2) at dosages of 0.05 mg/kg and 0.1 mg/kg (i.p.) daily for 90 days reveal a graded inhibition of delta 5-3 beta OHD activity which was positively related to dosage and to the duration of treatment with this compound. This phenomenon may be mainly responsible for the inhibition of spermatogenesis, observed as a toxic manifestation of mercury compounds.