A positive feedback effect of oestradiol on LH release in the male marmoset monkey, Callithrix jacchus

Abstract

S.c. injection of estradiol benzoate in oil, resulting in a sustained elevation of circulating estradiol levels, induced an initial suppression of LH [luteinizing hormone] secretion, followed by a positive discharge of LH in castrated male and female and in intact male marmosets. Estrogen-induced LH release (producing maximum LH concentrations 24 h after the injection) was observed in 75% of castrated males and females. A positive discharge of LH occurred in 50% of intact males 28-36 h after estrogen administration.