Association of Serum and Follicular Fluid Leptin Concentrations with Granulosa Cell Phosphorylated Signal Transducer and Activator of Transcription 3 Expression in Fertile Patients with Polycystic Ovarian Syndrome

Objective: Our objective was to evaluate whether polycystic ovarian syndrome (PCOS)-associated infertility is related to alterations of leptin, leptin receptor (Ob-R), and the phosphorylated signal transducer and activator of transcription 3 (p-STAT3)/suppressor of cytokine signal 3 (SOCS3) system in the ovary. Design and Setting: A case-control study was conducted in a university hospital. Patients: Thirty-one infertile PCOS women with oligoovulation plus polycystic ovarian morphology and 79 infertile women with tubal blockage (control) participated in the study. The subjects were stratified according to in vitro fertilization outcomes: successful and failed subgroups. Methods: Serum and follicular fluid (FF) leptin levels were measured with ELISA. RT-PCR and Western blotting were performed to assess expression of mRNA encoding leptin and Ob-R and proteins of p-STAT3 and SOCS3 in granulosa cells (GCs). Results: Leptin levels in serum and FF of PCOS women were significantly higher than those of control (P...