Precocious sexual development in female rats with hypothalamic lesions.

Abstract

SummaryTwo types of precocious sexual development were found in female rats with hypothalamic lesions. Anterior lesions were followed by precocious ovarian follicular growth with uterine and vaginal manifestations of estrogen secretion. Lesions damaging part of the arcuate nucleus had not only these sequelae, but also ovarian luteinization. These results are interpreted to mean that anterior lesions increased FSH release, whereas arcuate nucleus lesions increased both FSH and LH release. Together with results of other studies, they suggest that anterior lesions may damage an FSH inhibitory mechanism. The results of arcuate nucleus lesions do not necessarily imply that an LH inhibitory mechanism was destroyed, however. The possibility that such lesions may act by irritating a gonadotropin stimulating mechanism is discussed.