Selective effect of androgens on lh and FSH release in anterior pituitary cells in culture

Abstract

A possible direct effect of androgens at the pituitary level on gonadotropin release was studied using rat anterior pituitary cells in primary culture. The preincubation of cells with 3 × 10−9M testosterone (T) for 40 h increased the concentration of luteinizing hormone-releasing hormone (LHRH) required for half-maximal stimulation (ED)50() of LH)release from 3 × 10−10M to 1 × 10−9M. In the same experiment, the LHRH ED50 for FSH release (3 × 1O−1OM) was not affected by preincubation with T, while a slight stimulatory effect of the androgen was observed on basal FSH release and on the maximal FSH response to LHRH. Time-course experiments showed that the inhibitory effect of T on the LH response to LHRH was maximal after about 48 h of incubation and that 54 h after the removal of T, only 50% of the inhibition was reversed. 5α-Dihydrotestosterone (DHT) and T led o t the same maximal inhibition (15-20% of control) of the LH response to 10−10M LHRH. DHT was, however, about 3 times more potent than T, their ED50 values being 1.6 × 10−10M and 5 × 10−10M, respectively. In contrast to the effect on LH, the FSH response to 10−10M LHRH was only slightly, but not significantly, inhibited by increasing concentrations of DHT or T. The finding that total LH (medium + cell content) remained constant after incubation with T or DHT clearly indicates that the inhibition of the LH response to LHRH is really due to changes in the sensitivity of the releasing mechanisms in the LH-secreting cells. Androgens did, however, lead to increased total FSH. The present data indicate an independent control of LH and FSH secretion by a direct action of androgens at the pituitary level. © 1976 by The Endocrine Society.