thecal cell

The thecal cells around each follicle secrete estrogen.

In females, it is synthesized in the ovaries by Thecal cells in very small quantities.

In adult ovarian follicles, granulosa and thecal cells functional Sertoli-like and Leydig-like cells (-Foxl1)

LH induces androgen synthesis by thecal cells, stimulates proliferation, differentiation, and secretion of follicular thecal cells and increases LH receptor expression on granulosa cells.

It is also synthesized in far smaller quantities in women by the thecal cells of the ovaries, by the placenta, as well as by the zona reticularis of the adrenal cortex and even skin in both sexes.

In support of this, BRCA1 expression has been shown to occur in the mouse ovary (granulosa and thecal cells of small and medium follicles) independent of hormonal status, and even in ovaries from estrogen receptor -/- deficient mice [ 41, 42].