Experimental studies of the effects of estradiol and thyroxine on the fascicular layer of the adrenal cortex

: We studied the effects of estradiol and thyroxine on the secretory function of the adrenal gland cortex in castrated female rats. We evaluated steroidogenesis on the basis changes in histochemical reaction to lipids and corticosterone blood concentrations in adrenal and peripheral veins obtained from RIA studies. It was found that estradiol stimulated or inhibited the synthesis of corticosterone in a dose-dependent manner. In contrast thyroxine alone or combined with estradiol (irrespective of the dose) enhanced steroidogenesis in the adrenal glands of castrated female rats.