[Analysis of hypothalamo-hypophyseal-gonadal interrelationships in female rats in experimentally induced diabetes].

Hypothalamo-hypophyseo-gonadal system functional activity was studied in rats with streptozotocin diabetes. In intact rats concentrations of sex hormones nuclear receptors were measured in the hypothalamic preoptic-anterior, mediobasal segments and in the adenohypophysis, as were blood serum gonadotropins and sex hormones. Estradiol and progesterone were injected to ovariectomized females and LH-RH levels measured in preoptic-anterior segment of the hypothalamus, arcuate nucleus, and median eminence, as well as LH and FSH concentrations in the blood in order to detect disorders in basal and cyclic gonadotropin secretion. Streptozotocin injection to cycling females disordered the estrous cycle and was associated with reduction of LH, FSH, and sex hormones basal and cyclic secretion. Estradiol nuclear receptors concentrations reduced in the preoptic-anterior hypothalamus and hypophysis, the count of nuclear testosterone-binding sites reduced only in the hypophysis. Gonadotropin wave stimulated with sex steroids in ovariectomized females was reduced in diabetes because of changed activity of LH-RH-producing system. We believe that changes in basal and cyclic secretion of gonadotropins in rat females with experimental diabetes is explained by reduced activity of LH-RH-producing system and receptor binding at the level of the hypothalamo-hypophyseal complex.