Major substrate precursor of adrenal cortex hormones?

• A. Cholesterol
• B. Glucose
• C. Proteins
• D. Nucleotides

Answer: (A)

Steroid hormones of the adrenal cortex are synthesized from cholesterol. In steroidogenesis, cholesterol is converted in the mitochondria to pregnenolone, the first step toward producing cortisol, aldosterone, and adrenal androgens. The other options don’t serve as direct precursors for these hormones—glucose is mainly an energy source (and can feed metabolism indirectly), while proteins and nucleotides are not converted into steroid hormones. Thus cholesterol is the major substrate precursor.