Adrenal estrogens in relation to ovarian function.

Abstract

Abstract-The effect of gonadotropins and ovarian hormones on adrenal estrogens in female rats was examined in relation to the ovarian function. Pregnant mare serum gonadotropin (PMS) increased adrenal estradiol level in intact rats but did not alter estrone levels. Human chorionic gonadotropin (HCG) with PMS did not alter the estrone and estradiol levels. Neither PMS or HCG with PMS affected these steroid levels in ovariectomized rats. Injection of hexestrol to intact rats decreased the estrone level. Further decrease in the estrone level resulted after administration of hexestrol with progesterone.In a developmental study, the estrone level at 35 days of age was higher than that at 50 and 80 days of age. The estrone level gradually decreased with adrenal development after ovariectomy performed at 21 days of age. When adrenal slices were incubated with either 3H-estrone or 3H-estradiol, higher radioactivity of estrone accumulated in the adrenal gland of immature rats than in that of adult rats. There was a larger conversion of 3H-estradiol to 3H-estrone than the reverse process in both immature and adult rats. These results indicate that the adrenal estrogens were influenced by ovarian function.The interaction between the adrenal glands and gonads has been suggested from findings of fluctuation in adrenal estradiol at proestrus (1). From the point of the close histological and biochemical relationship, there may be an interaction between adrenal glands and gonads. With respect to the physiological role of ovarian estradiol in the adrenal gland, it has been reported that estradiol enhanced corticosterone production and inhibited the activity of 5a-reductase in rat adrenal gland (2, 3). Recently, evidence has been reported for cellular and nuclear receptors of estradiol in the adrenal gland of rats and mice (4, 5).As little is known of the relationship between adrenal estrogens and the ovarian function, the effect of gonadotropins and ovarian hormones on adrenal estrogens was examined in relation to the ovarian function. MATERIALS AND METHODSAnimals: Female Wistar rats weighing approx. 200 g, or immature rats (21-35 days) were used. The rats were housed in a room kept at 24 + 1 °C on a lighting schedule of 12-hr light (6:00 h to 18:00 h) : 12-hr darkness with free access to food and water. Vaginal smear was recorded daily for each rat. Puberty was determined by daily inspection for vaginal opening. Ovariectomy was performed by a dorsal approach with the rats under ether anesthesia. Ovariectomy was also performed in immature rats at 21 days of age.The surgically treated rats were sacrificed 15, 30, and 60 days after the operation and the