Fig. 1.

Adrenal steroidogenesis. This schematic illustrates the biosynthesis pathways of mineralocorticoids, glucocorticoids, and sex steroids in the adrenal cortex by highlighting the predominant substrates and products within each zone. The three zones, zona glomerulosa (ZG), zona fasiculata (ZF), and zona reticularis (ZR), are labeled and designated with different background colors. Boxes denote steroidogenic enzymes, and arrows represent directionality of the enzymatic reactions. The pathway begins in the upper left hand corner with the conversion of cholesterol to pregnenolone. Multistep conversions are indicated with multiple arrows when the enzymes are not specified