The role of estrogen in the modulation of pituitary sensitivity of LRF (luteinizing hormone-releasing factor) in men

Abstract

The role of estradiol in modulating pituitary gonadotropin release in the human male was studied by evaluating the effects of clomiphene on the pituitary gonadotropin response to synthetic LRF (150 mug) in 6 eugonadal men. Administration of clomiphene (100 mg single daily dose time 5 days) induced a significant elevation of the basal levels of LH, FSH, estradiol and testosterone. However, the pituitary release of LH and FSH in response to LRF was markedly diminished by the clomiphene treatment. This finding suggests that in men, as in women, endogenous estradiol provides feedback regulation of gonadotropin output by the pituitary.

PIP: The effects of clomiphene on the pituitary response to LRF in eugonadal men were studied to investigate the role of estradiol in the feedback modulation of gonadotropin secretion in men. 150 mcg LRF was given to 6 healthy men (20-28 years) and luteinizing hormone (LH) and follicle stimulating hormone (FSH) evaluated. A 5-day course of clomiphene (100 mg daily) was then given and the LRF test repeated. Serum FSH, LH, estradiol, and testosterone (T) were determined. Clomiphene caused a significant elevation in the basal levels of LH, FSH, Estradiol, and T. Pituitary release of LH and FSH in response to LRF was markedly reduced by clomiphene treatment indicating that estradiol provides feedback regulation of gonadotropin output by the pituitary.