Biochemical studies suggest that 17,20-lyase activity, and thus efficient synthesis of androgens by human P450c17, requires both reductase and the accessory protein cytochrome b5. Since the human and primate zona reticularis (ZR) secrete androgens, the expression of these proteins, and of 3β-HSD, was investigated by immunocytochemistry in the adrenal cortex of the mature rhesus macaque. Cytochrome b5 expression was restricted to the cells of the ZR which appeared deficient in 3β-HSD. However, both P450c17 and reductase were evident throughout the zona fasciculata. These data provide essential evidence in support of a functional role for cytochrome b5 in the regional control of 17α-hydroxylase and 17,20-lyase activities of P450c17 and thereby adrenal C19 steroid secretion by the primate adrenal gland.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Clinical Endocrinology and Metabolism|
|State||Published - 1999|
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism