Résumé
Objective To investigate the expression of phosphatidylinositol 3-kinase(PI-3K)in adipose tissue of polycystic ovary syndrome patients(PCOS),and explore molecular mechanisms of insulin resistance(IR)in PCOS.Methods Samples from patients with PCOS with IR(n=19),PCOS without IR (n=10)and controls(n=15)were collected.Serum fasting insulin(FIN)and fasting plasma glucose (FPG)were measure& Insulin resistance index was calculated using homeostasis model assessment (HOMA)to analyze the relationship between these markers and IR.Western blot technique was used to detect the PI-3K p85 subunit.Gene expression of PI-3K p85 subunit was detected by reverse transcription polymerase chain reaction(RT-PCR)method.Kinase activity was detected by immunoprecipitation,thin- layer chromatography and gamma scintillation counting.Results(1)The levels of FIN[(25.2?3.8) mU/L]and HOMA-IR(1.6?0.3)in PCOS with IR were significantly higher than those in PCOS without IR[(13.4 +3.8)mU/L,0.9?0.3]and controls[(9.5 +2.6)mU/L,0.5?0.3;all P＜0.05).(2) There was no significant difference in the protein(0.65?0.10)and gene expression(0.92?0.12)of PI-3 K p85 subunit in PCOS with IR compared with PCOS without IR(0.72?0.10,1.01?0.10)and control groups(0.73?0.14,1.00?0.12;P＞0.05).(3)PI-3K activity in PCOS with IR(81%)and PCOS without IR(89%)was significantly decreased(P＜0.01,P＜0.05)and negatively correlated with HOMA- IR(r=-0.69,P＜0.01;r=-0.62,P＜0.05).Conclusions No significant difference in the protein and gene expression of PI-3K p85 subunit in PCOS with IR is found.The decreased PI-3K activity may lead to IR of PCOS.