The Ovary- A Source of Androgens in PCOS.

The ovaries are involved in a vicious cycle where they are stimulated to produce excessive androgens leading to abnormal follicular growth, lack of ovulation, and the excessive androgen production and the cutaneous manifestations of the syndrome. The diagram below shows the overall structure of the ovary. Basically, there are two-compartments (Figure 1). The theca cells surround the follicles. These produce androgens which act as precursors of the follicular estrogen production by granulosa cells. Elevated insulin, or tonic elevations of luteinizing hormone may lead to excessive androgen production, as shown in Figure 2.

Figure 1. Ovarian compartments.

Theca cells- surround follicles and make androgens that are the precursors of estrogen

made in follicles. Stimulated by LH. Women with PCOS over produce

androgens.

Granulosa cells- cells within follicle, FSH converts androgens to estrogen and helps to

nourish the egg.

Egg- largest cell in the follicle.

Figure 2. Elevated Insulin and LH drive the ovary to produce androgens.

Theca cell Blood vessel

These hormones travel in the blood vessels to have effects in other parts of the body. Androgens cause hirsutism and estrogen may cause endometrial hyperplasia.

Androgen

Granulosa cell