Sexual differentiation of the steroid feedback mechanism regulating follicle-stimulating hormone secretion in the Syrian hamster.

摘要: The ability of gonadal steroid hormones to influence tonic follicle-stimulating hormone (FSH) secretion was investigated in Syrian hamsters. In Experiment 1, males were castrated as adults, and administered testosterone 20-, 30-, 40-, 50-mm silastic capsules (s.c.) at 67, 74, 81, 88 days, respectively. Circulating FSH reduced by a dose-dependent manner. A similar response adulthood evident neonatally androgenized hamsters given proprionate (TP) on Days 0 I life. By contrast, the absence androgens during neonatal period (females ovariectomized 60 days age orchidectomized birth) resulted only partial suppression circulating even highest dose adulthood. Treatment with estradiol benzoate birth failed produce masculine androgen 2, using protocol, nonaromatizable androgen, dihydrotestosterone, produced serum (30-, 60-, 90-mm capsules). However, dihydrotestosterone alter hypersecretion orchidectomy or females treated either vehicle TP. 3, treatment (10-, 30-mm capsules) decreased gonadectomized dosedependent manner; TP more responsive adults compared birth. Whether nonandrogenized neonates, largest did not completely block castration-induced rise FSH. results indicate that inhibition is sexually d(ffereiuiated dependent upon exposure testicular early development. females, suppress circulation suggested depend, for most part, aromatization estrogen. regulation release may be accomplished action pure androgen.