The impairment of progesterone-induced pituitary release of prolactin and gonadotropin in patients with hypothalamic chronic anovulation.

Sequential administrations of progessively increasing amounts of estradiol benzoate (EB) for five days followed by 10 mg. of progesterone (P) elicited a prompt pituitary release of luteinizing hormone, follicle-stimulating hormone, and prolactin in normal women during the early follicular phase but not in women with normogonadotropic hypothalamic chronic anovulation with or without associated hyperprolactinemia. Since hypothalamic dopamine functions as an inhibitor for the secretion of both prolactin and gonadotropin, we postulate that sequential EB-P stimulation for simultaneous release of gonadotropin and prolactin may be mediated by a reduction of hypothalamic dopamine in response to progesterone. The failure of patients with hypothalamic chronic anovulation to respond to this sequential ovarian steroid feedback demonstrated in this study may indicate the presence of dopaminergic dysfunction and that this test may prove to be useful in delineating hypothalamic function in amenorrhea patients.