Androgens in the feedback regulation of gonadotropin secretion in men: effects of administration of dihydrotestosterone to eugonadal and agonadal subjects and of spironolactone to eugonadal subjects.

To study the role of androgens in the feedback regulation of gonadotropin secretion, we measured the effects of administration of dihydrotestosterone undecanoate (DHTU) and of spironolactone. Basal and LRH stimulated LH/FSH levels were determined in: Six eugonadal men, before and after six weeks' DHTU 120 mg/day. Six agonadal subjects after 12 weeks' DHTU 120 mg/day. The results of B were compared to those of Six agonadal subjects without sex steroid treatment. Six eugonadal subjects were studied before and after six weeks' administration of spironolactone. In the two groups of eugonadal subjects, administration of either dihydrotestosterone or spironolactone had no effect on basal and LRH-stimulated gonadotropin levels. A clear but modest suppression was observed in agonadal subjects. Possibly DHT exerts some suppressive effect on gonadotropin secretion in the absence of other testicular products (estradiol, testosterone, inhibin), known to play a role in the negative feedback regulation. From these data it seems unlikely that in the eugonadal male circulating DHT has an important role in the feedback regulation of gonadotropin secretion.