The hypothalamic factor influencing secretion of the luteinizing hormone of the anterior hypophyseal lobe

Abstract

As demonstrated by the previous communication, administration of acid aqueous extract from hypothalamus or suspension of the posterior hypophyseal lobe to female rats whose ovaries had mature follicles, resulted in ovulation (Kabak and Sokolova, 1962). The paper presents the results of further investigations in which the same preparations of the posterior hypophyseal lobe or hypothalamus were administered during the first two days after hypophysectomy. Experiments were staged on infantile female rats which received gonadotropin from the pregnant mare serum to stimulate the preovulation growth of the follicles. In contrast with the females with intact hypophysis no ovulation was caused in hypophysectomized female rats either by hypothalamic extract, or by a posterior hypophysis lobe suspension. These data demonstrate that the hypothalamus and the posterior hypophysis lobe contain one or several substances stimulating the luteinizing hormone secretion by the anterior hypophysis lobe.