OESTROGEN SENSITIVE NERVOUS STRUCTURES IN THE HYPOTHALAMUS

Abstract

Small fragments of the ovary, grafted into the region of the para-ventricular nuclei of adult female Wistar rats, (group B) caused a significant decrease in uterine weight indicating inhibition of gonado-tropic activity as compared with normal control animals, (group A) or in rats with hepatic tissue grafted in the same region. The auto-implantation of non-specific tissue into the region of the paraventricular nuclei (group C), the grafting of ovarian tissue into the mammillary region (group D), auto-implantation of ovarian tissue into the anterior lobe of the hypophysis or into its immediate neighborhood (group E), had no significant effect on the secretion of gonadotropic hormones. It is suggested that estrogens affect the gonadotropic function of the hypophysis exclusively through a nervous mechanism. It is assumed that the functional state of nervous elements localized somewhere in the region of the paraventricular nuclei is modulated by the blood-level of estrogens and thus regulates the secretion of gonadotropic hormones.