Abstract: Objective To research the expression of protein insulin receptor substrate( IRS ) and the level of tyrosine phosphorylation in the endometrium of the patients with polycystic ovary syndrome( PCOS)and investigate the correlations between the expressions and the resistance of insulin. Methods Thirty patients with PCOS served as experimental group according to the diagnostic criteria, and 30 females hospitalized synchronously with regular menstrual cycle,normal serum sex hormone, fasting plasma glucose and fasting insulin levels as control group. According to the homeostasis model assessment for insulin resistance,the PCOS group was divided into two groups,insulin resistance group ( group IR)17 cases and non insulin resistance group( group NIR )13 cases. The differences in the expression of IRS-1 and IRS-2 by immunohistochemistry among group IR,group NIR and control group, and the levels of tyrosine phosphorylation of IRS-1 and IRS-2 among the three groups were compared. Results The expressions of protein IRS-1 and IRS-2 and the levels of tyrosine phosphorylation of IRS-1 and IRS-2 in PCOS group were significantly weaker than those in control group ( P ﹤0 . 05 ). The expressions of protein IRS-1 and IRS-2 and the levels of tyrosine phosphorylation of IRS-1 and IRS-2 in the PCOS group with IR were obviously weaker than those in the PCOS group without IR( P﹤0 . 05 ). Conclusion It is obvious that the expressions of protein IRS-1 and IRS-2 declined and the degrees of tyrosine phosphorylation descended in the patients with PCOS. The abnormality is quite distinct in the patients of PCOS group with IR. It speculates that there is a close relationship between the abnormal expression of IRS,the descent of the degree of tyrosine phosphorylation and the genesis of IR in the endometrium of the patients with PCOS.

Key words: polycystic ovary syndrome, receptor, insulin, endometrium