Mechanism of action of 17 alpha-propyltestosterone in inhibiting hamster flank organ development

Win 17,665 [topterone, (17 beta)-17-hydroxy-17-propylandrost-4-en-3-one] inhibited stimulation of flank organ development of castrated immature male hamsters by both testosterone and dihydrotestosterone, whereas progesterone inhibited the stimulation by only testosterone. Topical application of Win 17,665 on the flank organs of the male hamster did not cause any significant effect on testosterone metabolism of this tissue. In addition, there was no decrease in the lipogenic capacity of the flank organ. The evidence presented indicates that Win 17,665 exerts its antiandrogenic action by binding with the cytosolic Androgen Receptor(s) in the flank organ thus inhibiting the action of dihydrotestosterone.