Structure and hormonal output of the adrenal gland after experimental estrogenization of male rats.

Orchidectomy and estrogenization of the male represent a procedure that is applicable in sex reassignment or in prostate cancer therapy. This approach has an influence on the hypothalamic-pituitary-adrenal axis and thus affects cardiovascular function and metabolism. We utilized orchidectomized rats to evaluate the effects of estradiol on the structure and hormonal output of the adrenal gland. Adult Wistar rats were divided into sham-operated (SO; n=7), orchidectomized (Orx; n=7), and estradiol-treated orchidectomized (Orx+E; n=7) groups. Estradiol-dipropionate (0.625 mg/kg b.m.) was administered subcutaneously for three weeks, while the SO and Orx groups received vehicle alone. Set objectives were achieved using histochemistry/immunohistochemistry, stereology, and immunoassays. In Orx+E rats, the hormonal milieu was characterized by decreased testosterone and increased ACTH, compared with the Orx group. Also, orchidectomy and estradiol treatment provoked a significant increase in adrenal cortex volume and volume of ZF <i>per se</i>, with increased cell and nuclei volumes in all three adrenocortical zones (ZG, ZF, and ZR), in comparison with Orx rats. Concentrations of aldosterone in blood, as well as corticosterone in blood and adrenal tissue were increased, while circulating DHEA was decreased (with increased immunoexpression of adrenocortical CYP 17 enzyme), all in Orx+E compared with Orx animals. The wide zonal distribution of VEGF and the pronounced blood supply within the ZF of Orx+E animals acted to support the synthesis and secretion of corticosteroids. These results seem cautionary in the context of young male estrogenization, given the negative impact of high mineralocorticoids and glucocorticoids on cardiovascular function and metabolism.