The effect of mammalian gonadotropins and homologous gonadotropins on the activity of delta 5-3 beta-hydroxy-steroid-dehydrogenase (HSD) in hypophysectomized Rana esculenta.

Mammalian gonadotropins and partially purified gonadotropins (FSH and LH) from an amphibian (Rana esculenta) were used to investigate their action on enzymatic activity of delta 5-3 beta-HSD in male and female hypophysectomized Rana esculenta in stage of genital activity (October) and in stasis or hibernation stage (January). Amphibian and equine LH stimulate delta 5-3 beta-HSD activity especially in females hypophysectomized in the stage of genital activity, while ovine FSH action is very low and amphybian FSH practically inactive. The present data suggested that control of gonadotropic activity in the reproductive cycle in Rana esculenta is LH-dependent.