EFFECT OF GONADAL STEROIDS ON THE PITUITARY RESPONSIVENESS TO SYNTHETIC LUTEINIZING HORMONE RELEASING HORMONE IN THE MALE DOG

Abstract

SUMMARY Intravenous injections of synthetic luteinizing hormone releasing hormone (LH-RH) stimulated LH secretion in male dogs. An i.m. injection of 0·025–2·5 mg oestradiol-17β given 2·5 h but not 24 h before administration of LH-RH blocked LH secretion. Diethylstilboestrol (2·5 mg) also blocked LH secretion but meso-dihydrodibutylstilboestrol (2·5 mg) was without effect. Testosterone (2·5 and 25 mg), dihydrotestosterone (2·5 mg), 5α-androstane-3α, 17β-diol (2·5 mg), 5α-androstane-3β, 17β-diol (2·5 mg), 5α-androstane-3α, 17α-diol (0·125 mg), 5α-androstane-3β, 17α-diol (0·125 mg) and progesterone (25 and 50 mg) did not prevent LH-RH stimulation of LH secretion.