OBJECTIVETo study the expression of insulin receptor substrate-1(IRS-1) and insulin receptor substrate-2 (IRS-2) in pancreas of rats with intrauterine growth retardation (IUGR).

METHODSAn IUGR rat model was prepared by protein malnutrition during pregnancy. The pancreas samples of the IUGR pups were obtained at birth, and 3 weeks and 8 weeks of age. The expression of IRS-1 and IRS-2 mRNA were ascertained by RT-PCR. Western blot was used to measure the protein expression of IRS-1 and IRS-2. The rat pups born from the mother rats who received normal diet during pregnancy severed as the control group.

RESULTSThe expression levels of IRS-2 mRNA and protein in pancreas of the IUGR group were significantly lower than those in the control group at all three time points (P<0.05). There were no significant differences in the expression levels of IRS-1 mRNA and protein in pancreas between the IUGR and the control groups.

CONCLUSIONSThe IRS-2 expression levels in pancreas in IUGR rats decrease significantly at birth, and 3 weeks and 8 weeks of age. This might be one of the molecular mechanisms for the development of metabolic syndrome in later life in IUGR individuals.