Immunohistochemical localization of 17α-hydroxylase/C17-20 lyase and aromatase cytochrome P-450 in polycystic human ovaries

Abstract

ABSTRACT Immunohistochemical localization of 17α-hydroxylase/C17-20 lyase (P-45017α,lyase) and aromatase cytochrome P-450 (P-450arom) in polycystic ovary (PCO) syndrome was studied using specific polyclonal antibodies which had been raised against the corresponding enzymes. In the majority of follicles that were atretic and smaller than 7 mm in diameter, theca interna cells showed high P-45017α,lyase immunoreaction, while small numbers of granulosa cells showed little P-450arom immunoreaction. In some atretic follicles that were larger than 11 mm in diameter, the hyperplastic theca interna cell layer showed high immunoreaction to P-45017α,lyase, while the poorly proliferated granulosa cell layer showed a mixture of weak and negative immunoreaction to P-450arom. No immunoreaction to P-45017α,lyase or P-450arom was recognized in PCO stroma. These findings suggest that the theca interna cells and the granulosa cells from PCOs show abnormal steroidogenic function, while the localization of P-45017α,lyase and P-450arom in PCOs was essentially identical to that in the normal ovary. Theca interna cells in PCO atretic follicles are the main site of excess androgen production. Journal of Endocrinology (1993) 139, 503–509