Abstract: Objective To explore the effect of visfatin on the expression of insulin receptor substrate 1 and 2(IRS-1,IRS-2)in ovarian granulosa cells from patients with polycystic ovarian syndrome(PCOS).Methods Ovarian granulosa cells of infertile women with tubal obstruction without insulin resistance(IR)(NO,n=15),PCOS without IR(PCOS-NIR,n=14)and PCOS with IR(PCOS-IR,n=12)were cultured.Serum and follicular visfatin were measured by enzyme-linked immunosorbent assay(ELISA).By treating with super-physiological concentrations of visfatin(100 ng/ml),the mRNA and protein expressions of IRS-1 and IRS-2 in ovarian granulosa cells were obtained by semi-quantitative reverse-transcription PCR(RT-PCR)and western blot,respectively.Results Serum and follicular fluid visfatin levels were significantly higher in the PCOS-NIR and PCOS-IR group than those in NO group.Compared with the NO group,granulosa cells in the PCOS-NIR and PCOS-IR group had higher IRS-1 mRNA and protein expression(P<0.05),but lower IRS-2 mRNA and protein expression(P<0.05).This trend was more obvious than before visfatin administration in the three groups.Conclusion Whether or not accompanied by IR,the elevated levels of visfatin in PCOS may cause the balance disorders of ovary IRS-1/IRS-2.