Sex differences in adrenocortical structure and function. IX. Stereologic studies on the effects of gonadectomy and testosterone or estradiol replacement on adrenal cortex of adult male and female hamsters.

Adrenal glands of adult male hamster are heavier than in female and this sex difference depends primarily on the greater number of adrenocortical cells and their larger size in male gland if compared to female. The aim of the study was to explain the relationship between the sex hormones and the structural of adrenal cortex of male and female hamsters. Orchidectomy lowered the adrenal weight, an effect partially reversed by testosterone. Changes induced by orchidectomy were found mainly in fasciculata and reticularis zones, after testosterone replacement the volume of the former did not differ from control males. Removal of testes lowered the volume of individual zona reticularis cell, after testosterone administration the volume of these cells did not differ from control males. Neither ovariectomy, nor estradiol replacement has a desired effect on the above mentioned parameters in female adrenal cortex. In both sexes gonadectomy lowered the total number of adrenocortical cells and this effect is not restored to normal by 12-days testosterone or estradiol action. Results obtained suggest that the sex dimorphism in the size and structure of hamster adrenal cortex depends on the stimulatory action of testosterone on the gland while estradiol has no distinct effect on parameters studied.