PCOS患者卵巢胰岛素抵抗的发生机理探讨

目的:探讨胰岛素抵抗/高胰岛素血症在PCOS生殖功能障碍中的作用。方法:收集行IVF-ET治疗的11例PCOS患者(PCOS组)和15例排卵正常的输卵管性不孕患者(对照组)促排卵后卵巢黄素化颗粒细胞,行体外培养,分别用不同浓度胰岛素处理细胞48h,采用RT-PCR和Westernblot检测黄素化颗粒细胞胰岛素受体底物(IRS)-1和IRS-2mRNA及蛋白的表达。采用放射免疫法检测血清性激素及空腹血清胰岛素(FIN)水平;采用葡萄糖氧化酶法测定空腹血糖(FPG)水平;计算胰岛素抵抗指数(HOMA-IR)。结果:①PCOS患者血清LH、LH/FSH、T、FIN及HOMA-IR均明显高于对照组(P<0.05);②0mU/ml胰岛素时,PCOS组黄素化颗粒细胞IRS-1mRNA及蛋白的表达水平明显高于对照组(P<0.05),而IRS-2mRNA及蛋白的表达水平较对照组明显降低(P<0.05);③10mU/ml胰岛素对二组患者黄素化颗粒细胞IRS-1和IRS-2mRNA及蛋白的表达均无影响(P>0.05);④100mU/ml或1000mU/ml胰岛素作用后,二组患者IRS-1mRNA及蛋白的表达水平均明显增高(P<0.05),而IRS-2mRNA及蛋白的表达水平均明显降低(P<0.05)。结论:PCOS患者胰岛素抵抗/高胰岛素血症通过提高卵巢颗粒细胞IRS-1的表达,降低IRS-2的表达参与患者卵巢生殖功能障碍的发生。

Molecular Mechanism of Ovary Local Insulin Resistance in Polycystic Ovarian Syndrome Patients

Objective: To explore the roles of insulin resistance and hyperinsulinemic in the pathogenesis of inordinate ovary function of polycystic ovaries syndrome (PCOS). Methods: Ovarian luteinizing granulosa cells from PCOS patients (n=11) and tubal infertile patients with normal ovulatory (control group, n=15) were obtained in the process of IVF-ET. Serum LH, FSH, T and fasting insulin (FIN) were measured by radioimmunoassay. Fasting plasma glucose (FPG) was measured by oxidase assay. Insulin resistance index (IR) was calculated using homeostasis model assessment (HOMA). Collected luteinizing granulosa cells were cultured in vitro. After treated with different concentrations insulin for 48 h, the mRNA expression of insulin receptor substrates (IRS-1, IRS-2) in ovarian luteinizing granulose cells was assessed by semi-quantitative RT-PCR. The protein expression of (IRS-1, IRS-2) in ovarian luteinizing granulose cells were analyzed by Western blot. Results: (1) The levels of LH, LH/FSH, T, FIN and HOMA-IR in PCOS patients were significantly higher than those in control group. (2) At the 0 mU/ml insulin, PCOS luteinizing granulose cells had higher IRS-1 mRNA expression and protein content (P<0.05), but lower IRS-2 mRNA expression and protein content (P<0.05) as compared with the control. (3)Treated with 10 mU/ml insulin, the mRNA expression and protein content of IRS-1, IRS-2 were unchanged in both PCOS group and control group (P>0.05). (4) However, treated with 100 mU/ml or 1 000 mU/ml insulin, the IRS-1 mRNA expression and protein content were increased remarkably (P<0.05) and the IRS-2 mRNA expression and protein content were reduced notably (P<0.05) in both PCOS group and control group, and the response of luteinizing granulosa cells to insulin between the two groups was not statistic different(P>0.05). Conclusion: The insulin resistance and hyperinsulinemic may participate in the pathogenesis of inordinate ovary function of PCOS by up-regulated IRS-1 mRNA and protein expression and decreased IRS-2 mRNA and protein expression.