[Development of hypothalamic regulation of gonadotropic function of the pituitary in hypoinsulinemic rats]

Effects of temporary hypoinsulinemia induced by streptozotocin in neonatal age on the development of the mechanism of hypothalamic regulation of hypophyseal gonadotropic function in rats were studied. With this aim the authors analyzed the status and functional capacity of feedback system mediating hypothalamic regulation of gonadotropin secretion in female and male rats at the age when this system starts functioning in health. Streptozotocin injection in the neonatal age induced a reduction of estradiol concentration and of estradiol and progesterone-stimulated preovulatory peak of luteinizing hormone (LH) in 28-day-old females and a reduction of LH concentration in 28-day-old castrated males. Reduced estradiol and LH peak were observed in adult females injected streptozotocin during the first week of life and reduced LH level in adult males. These results permit a hypothesis that streptozotocin administration to rats in the neonatal age disturbed the mechanism of hypophyseal gonadotropic function regulation in mature rats.