Assessment of the expression of IRβ, IRS-1, IRS-2 and IGF-IRβ in a rat model of intrauterine growth restriction

Fetal Diagn Ther. 2010;28(3):145-52. doi: 10.1159/000316932. Epub 2010 Aug 19.

Abstract

Objective: To investigate glomerular development and expression of insulin and insulin-like growth factor receptors in an experimental model of intrauterine growth restriction (IUGR).

Material and methods: We studied three groups of Sprague-Dawley fetuses: IUGR - restricted by ligation of the right uterine artery; C-IUGR - left horn controls, and EC - external controls (non-manipulated). Body and organs were weighed, and glomerular number and volume were analyzed. Expression of IRβ, IRS-1, IRS-2 and IGF-IRβ was analyzed in liver, intestine and kidneys by immunoblotting.

Results: Organ/body weight ratios were similar. In IUGR, glomerular number and volume were increased compared to C-IUGR and EC (p<0.001). In the IUGR liver, increases were found in IGF-IRβ compared to C-IUGR and EC; IRβ compared to EC, and IRS-2 compared to C-IUGR. However, decreases in IRβ were noted in IUGR compared to C-IUGR; IRS-1 compared to C-IUGR and EC, and IRS-2 compared to EC. In IUGR intestine, increases were detected in IRβ, IRS-1 and IGF-IRβ compared to C-IUGR and EC. In IUGR kidneys, increases were observed in IRβ and IGF-IRβ compared to C-IUGR and EC, and IRS-1 compared to EC. Decreased IRS-2 in the intestine and kidney were noticed in IUGR compared to C-IUGR and EC.

Conclusion: IUGR fetuses had less glomeruli and alterations in insulin receptors, which may be associated with an increased risk of disease occurrence in adulthood.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Weight
  • Disease Models, Animal
  • Female
  • Fetal Development
  • Fetal Growth Retardation / metabolism*
  • Fetal Growth Retardation / physiopathology
  • Fetus / chemistry
  • Fetus / metabolism
  • Insulin Receptor Substrate Proteins / analysis
  • Insulin Receptor Substrate Proteins / metabolism*
  • Intestinal Mucosa / metabolism
  • Intestines / chemistry
  • Intestines / growth & development
  • Kidney / chemistry
  • Kidney / growth & development
  • Kidney / metabolism
  • Liver / chemistry
  • Liver / growth & development
  • Liver / metabolism
  • Organ Size
  • Pregnancy
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Insulin / analysis
  • Receptor, Insulin / metabolism*
  • Receptors, Somatomedin / analysis
  • Receptors, Somatomedin / metabolism*

Substances

  • Insulin Receptor Substrate Proteins
  • Irs1 protein, rat
  • Irs2 protein, rat
  • Receptors, Somatomedin
  • Receptor, Insulin