Figure 4.
Organization of the adrenocortical zones. The area within the dotted square contains the core steroidogenic activities common to zona reticularis, ovarian theca cells, and testicular Leydig cells (although the latter express 17ßHSD type 3 rather than 17ßHSD5). The left column shows the Δ 5-3ß-hydroxysteroid pathway and the columns to its right shows the Δ 4-3-ketosteroid pathway. The adrenal zones are color-coded to facilitate visualizing overlapping and unique steps in the adrenal zones: the top row shows the zona glomerulosa pathway to mineralocorticoids culminating in aldosterone; the second row shows the zona fasciculata pathway to cortisol. The third row shows the zona reticularis steps to DHEAS and other 17-ketosteroids. The steroidogenic and accessory enzymes are italicized and abbreviated as in Figure 3 side panel. P450c11ß1 is expressed only in the zona fasciculata (P450c11ß1 blue lettering on mineralocorticoid pathway indicates the zona fasciculata formation of corticosterone, not shown) and zona reticularis. 3ßHSD2 expression is lower in the zona reticularis than other zones. Dotted P450c17 17,20-lyase pathways for Δ4-3-ketosteroids are relatively minor.
Modified with permission from Rosenfield RL. Identifying children at risk of polycystic ovary syndrome. J Clin Endocrinol Metab. 2007;92:787-796.