Demonstration of a direct effect of inhibitors of the degradation of receptor-bound human choriogonadotropin on the steroidogenic pathway.

Results presented in the previous paper (Ascoli, M., and Puett, D. (1978) J. Biol. Chem. 253, 7832--7838) show that the degradation of receptor-bound 125I-labeled human choriogonadotropin can be inhibited by chloroquine, protease inhibitors, and metabolic inhibitors. These compounds were also shown to inhibit gonadotropin-stimulated steroidogenesis. It is reported herein that these inhibitors also block the stimulation of steroidogenesis by both cholera toxin and 8-Br-adenosine 3':5'-monophosphate, thus showing that they are not specific for the hormonal stimuli. These results, taken together with previous observations that show that NH2Cl can block hormone degradation without inhibiting hormone-stimulated steroidogenesis, strongly suggest that the degradation of choriogonadotropin is not required for its stimulatory action on progesterone production.