[Plasma LH-RH levels in normal men and women with increasing age, in women with castration, climacteric syndrome, also in pregnancy, delivery and puerperium].

In order to further clarify hypothalamic function, plasma LH-RH was measured by a sensitive radioimmunoassay in normal men and women with increasing age, in women with castration, climacteric syndrome, also in pregnancy, deliver, and puerperium. The following results were obtained: 1) Plasma LH-RH levels were the same in the follicular and luteal phases of adult and premenopausal women, and a gradual increase was noted through the premenopausal period. It had the highest peak in the group within one year after menopause, followed thereafter by a gradual decline throughout the senile period but still remaining higher than that in the adult period. 2) There was no change in plasma LH-RH in men between ages 22 and 55, but a slight increase was found over age 56. 3) There was a high plasma LH-RH peak in the first day after bilateral oophorectomy both in pre- and post-menopausal women. A slight increase was found postoperatively in the premenopausal but not in the postmenopausal group. 4) There was a low plasma LH-RH level in both pre- and post-menopausal women with climacteric syndromes. 5) There was a low plasma LH-RH level through 9-39 weeks of gestation and during labor, it became a little higher at one month postpartum than in non-pregnant women.