The Postmenopausal Ovary Is Not a Major Androgen-Producing Gland

Abstract

It is currently believed that the postmenopausal ovary remains a gonadotropin-driven, androgen-producing gland. However, the adrenal contribution to circulating androgen levels may explain some conflicting results previously reported. In addition, the steroidogenic potential and gonadotropin responsiveness of the postmenopausal ovary have not been recently reassessed. Plasma T, bioavailable T, free T, androstenedione (Adione), and dehydroepiandrosterone sulfate levels were measured in postmenopausal or ovariectomized women with complete adrenal insufficiency, compared with women with intact adrenals. A stimulation human chorionic gonadotropin test (on d 0, 3, and 6) was performed in postmenopausal women with adrenal insufficiency. Dexamethasone was administered for 4 d in postmenopausal women with intact adrenals. Intraovarian T and androstenedione were also measured in homogenates of ovarian tissue from postmenopausal women. Immunocytochemistry was performed on postmenopausal ovaries and premenopausal controls to detect the presence of steroidogenic enzymes (P-450 aromatase, P-450 SCC, 3β HSD, and P-450 C17) and gonadotropin receptors. Plasma androgen levels were below or close to the limit of the assay in all women with adrenal insufficiency. They were similar in postmenopausal and oophorectomized women with normal adrenals. No hormonal changes were observed after human chorionic gonadotropin injections in women with adrenal insufficiency. In contrast, a dramatic decrease of all steroids was observed after dexamethasone administration in postmenopausal women with intact adrenals. Intraovarian T and androstenedione levels were negligible in postmenopausal ovarian tissue. P-450 aromatase was absent from the 17 ovaries studied, and the enzymes for androgen biosynthesis were either absent (n = 13) or present in very low amounts (n = 4). In all the postmenopausal ovaries, FSH and LH receptors were completely absent. In the absence of adrenal steroids, postmenopausal women have no circulating androgens. This result is consistent with the immunocytochemical studies showing the almost constantly absent steroidogenic enzymes and LH receptors in the postmenopausal ovary. Thus, the climacteric ovary is not a critical source of androgens. The arrest of androgen secretion after menopause may impact significantly on women’s health.