TESTOSTERONE-SENSITIVE CENTERS IN THE HYPOTHALAMUS OF THE RAT

Abstract

ABSTRACT Microgram quantities of testosterone implanted in the basal tuberal-median eminence region of rats led to ovarian atrophy or atrophy of the seminal vesicles, prostate and testis thirty days later. Implantations in other areas of the diencephalon or in the pituitary gland did not result in weight changes in the sexual organs. The female showed a greater sensitivity to the testosterone implants than did the male. In the male, the degree of atrophy produced, appeared dependent upon the surface area of hormone present in the tuberal region, and considerable decreases in the weight of the sexual organs were noted without apparent changes in physiological function. The data suggest that the basal tuberal-median eminence area of the hypothalamus acts as the focus for »negative feedback« in the control of gonadotrophin secretion from the pituitary gland of the rat.