Objective    To study the transduction of insulin signals and the expression of glucose transporter in skeletal muscle of women with gestational diabetes mellitus (GDM) and the role of GDM in development of diseases.     Methods    Forty pregnant women were divided into normal glucose tolerance (NGT) group and GDM group

20 women in each group. A small amount of rectus abdominis was isolated and placed into a culture medium with or without insulin. mRNA expression levels of insulin receptor substrate 1 (IRS-1)

IRS-2

glucose transporter 2 (GLUT-2)

and GLUT-4 were measured by real time PCR. Phosphorylation of protein kinase B (Akt) and expression level of GLUT-4 were assayed by Western blotting.     Results    The expression levels of IRS-1

IRS-2 and GLUT-2 mRNA in basal state were significantly lower in GDM group than in NGT group (P0.05) and no significant difference was observed in expression of GLUT-4 mRNA between the two groups. However

after insulin stimulation

the expression level of GLUT-4 mRNA in basal state was significantly higher in NGT group than in GDM group (P0.05)

while the phosphorylation of Akt and the expression level of GLUT-4 were significantly lower in GDM group than in NGT group (P0.05).     Conclusion    Defects of key effector molecules at transduction and translation levels in the insulin signaling pathway of GDM patients can reduce the reaction to insulin

thus leading to insulin resistance.