this finding is in accord with the hypothesis that the pattern of pituitary gonadotropin secretion throughout the menstrual cycle ( basal secretion interrupted , once every 28 days on the average , by a preovulatory surge ) is not directed by alterations in hypothalamic gonadotropin-releasing hormone secretion but by the ebb and flow of ovarian estrogens acting directly on the pituitary gland .
C0018066
pituitary gonadotropin
C0018061
gonadotropin