Steroids modulate the release of luteinizing hormone from quail pituitary cells

Abstract

An enzymatically dispersed pituitary preparation from male Japanese quail ( Coturnix coturnix) was used to study the effects of gonadal and adrenal steroids on gonadotropin release. Cells were preincubated for 18 hr with or without steroids and then challenged with chicken luteinizing hormone-releasing hormone (cLH-RH I; Gln 8-LH-RH). Preincubation with testosterone (T; 10 n M) significantly suppressed ( P<0.05) luteinizing hormone release in response to cLH-RH I (10 ng/ml). Preincubation with 5α-dihydrotestosterone (5α-DHT) (10 n M) caused even further suppression of LH-RH-stimulated LH release while the same concentration of 5β-dihydrotestosterone and estradiol-17β had no effect. In addition, preincubation with corticosterone (10 n M) significantly ( P<0.01) suppressed the amount of LH released in response to cLH-RH I. Pituitary cells from immature males, when stimulated with cLH-RH I, released LH in a dose-related manner. Neither T nor 5α-DHT (10 n M) altered the effect of LH-RH. These data suggest that T and 5α-DHT play a role in mediating LH release in the avian pituitary while 5β-reduced androgens have no effect. These appears to be no androgen effect in the immature quail. In addition, corticosterone seems to be a factor in controlling gonadotropin secretion in the quail.