Intrafollicular insulin-like growth factor-II levels in normally ovulating women and in patients with polycystic ovary syndrome

Objective: To investigate intrafollicular insulin-like growth factor II (IGF-II) in patients affected with polycystic ovary syndrome (PCOS) in comparison with normal women. Design: Insulin-like growth factor-II was determined in 103 follicular fluids (FF) from normally ovulating women and in 102 FF from patients with PCOS. Ribonucleic acid was extracted from granulosa cells of follicles obtained from control and PCOS patients and from tissue from polycystic ovaries. Setting: Procedures were performed in a university laboratory. Patients: Twenty-nine normally ovulating women and 19 patients with PCOS underwent ovulation induction for IVF-ET with LH-releasing hormone (LH-RH) analog and gonadotropins. Eleven of them, 4 to 8 months later, underwent ovulation induction with approximately the same dosage of gonadotropins plus a standard dosage of GH. Main Outcome Measures: Intrafollicular IGF-II, IGF-I, epidermal growth factor (EGF), transforming growth factor beta 2, (TGF-beta 2), inhibin, and steroids were evaluated by appropriate RIA, immunoenzymatic assay (EIA), and ELISA assays. The expression of the gene encoding IGF-II was analyzed by Northern blot. Results: Intrafollicular IGF-II was lower in PCOS than in controls. Accordingly, IGF-II messenger RNA expression was lower in PCO than in normal granulosa cells. Several differences in FF IGF-I, EGF, inhibin, and TGF-beta 2 concentrations were observed between PCOS and controls. Conclusions: Both IGF-II and IGF-I were reduced in PCOS, confirming a possible role of an IGF imbalance in the development of this disease.