Abstract
A purified pituitary gonadotropin predominantly FSH activity was administered in graded doses to hypophysectomized and intact immature female rats, with and without concurrent administration of diethylstilbestrol in large doses. A more striking and consistent ovarian weight increase to pituitary gonadotropin, brought about 4111-4117 ENDOCRINE SYSTEM [Vol. 35] 356 through stimulation of early ovarian follicle development, regulation of further follicular progression, and depression of interstitial tissue overgrowth was observed in the diethylstilbestrol-treated hypophysecto-mized animals.