Sex steroidogenesis via the intracrine pathway. Androgens and estrogens synthesized in peripheral tissue including the breast require the presence of DHEA, an inactive precursor derived from the adrenal gland, and all of the appropriate enzymes. In addition to their synthesis, sex steroids are also inactivated in the same tissue thus minimizing widespread systemic effects. DHEA = dehydroepiandrosterone; DHEA-S = DHEA sulfated; 4-dione = androstenedione; A-dione = 5α-androstenedione; 3α-, 3β-, and 17βHSD = hydroxysteroid dehydrogenase; 5α-red = reductase.
