Adrenal Steroid Hormone Secretion

The adrenal glands consist of the adrenal cortex and the adrenal medulla. The adrenal cortex contains three functionally distinct cellular layers: the outer zona glomerulosa , the intermediate zona fasciculata , and the inner zona reticularis . The first zone produces aldosterone, the middle zone is responsible for the synthesis of cortisol, and the third zone is the site of adrenal androgen production. All adrenal steroid hormones are cholesterol derived and represent the final products of serial reactions catalyzed by enzymes of the cytochrome P450 family. Cortisol synthesis is mainly regulated by the hypothalamic–pituitary–adrenal axis, whereas aldosterone production is under the control of the renin–angiotensin system and circulating potassium concentrations. Adrenal androgen secretion is controlled by the adrenocorticotropic hormone and possibly other, yet unknown factors, such as the hypothetical ‘adrenal androgen–stimulating hormone.’