Context: In women with polycystic ovary syndrome, excess ovarian androgen production is driven by increased LH secretion. Studies conducted in animals suggest that the granulosa cell may influence LH-stimulated theca cell androgen production.

Objective: The objective of this study was to determine whether FSH enhances androgen production in women with polycystic ovary syndrome (PCOS) compared to that of normal women.

Design: A prospective study was conducted to compare androgen production in response to FSH in two groups of women.

Setting: The study was conducted in a General Clinical Research Center in a tertiary academic medical center.

Patients: Women with PCOS, 18–35 years (n = 20), and normal ovulatory controls, 18–35 years (n = 10), were recruited for study.

Interventions: Serial blood samples were obtained over a 24 hour period following an intravenous injection of r-hFSH, 150 IU.

Main Outcome Measures: The main outcome measures were serum 17-hydroxyprogesterone (17-OHP), androstenedione (A), dehydroepiandrosterone (DHEA), testosterone (T), and inhibin B (Inh B) responses following FSH administration.

Results: Basal serum 17-OHP, A, and T levels were markedly increased in women with PCOS compared to that observed in normal women. Basal DHEA and Inh B levels were similar to those of normal controls. Following FSH injection, PCOS women demonstrated enhanced production of 17-OHP, A, DHEA, and Inh B whereas in normal women no increases were observed. T levels declined slightly in both groups.

Conclusions: These findings provide evidence that, in PCOS women, theca cell androgen production is enhanced by FSH administration and suggest a granulosa-theca cell paracrine mechanism.