Effects of maternal protein malnutrition on fetal growth, plasma insulin-like growth factors, insulin-like growth factor binding proteins, and liver insulin-like growth factor gene expression in the rat

Pediatr Res. 1995 Mar;37(3):334-42. doi: 10.1203/00006450-199503000-00014.


We examined the effects of maternal dietary protein restriction on fetal growth and expression of IGF-I and -II, and IGF-binding proteins (IGFBP). We sought to dissociate the respective effects of maternal protein versus calorie restriction on growth indices and IGF synthesis by the neonates of protein-restricted dams. Pregnant Wistar rats (six to eight per group) fed a low (5%) protein diet throughout gestation had impaired body weight gain compared with controls fed a normal (20%) protein diet (by 45%, p < 0.001). Their serum and liver IGF-I concentrations and liver IGF-I mRNA concentrations were also reduced by 60, 80, and 50%, respectively. Serum IGFBP-3 was reduced by 60% in protein-restricted dams within 1 to 2 h after delivery (p < 0.001 versus controls), although IGFBP-1, -2, and -4 were not significantly affected by the dietary protein intake. In pups of protein-restricted dams, the mean body and liver weight at birth was 15-20% less than that observed in the progeny from normal protein-fed dams (p < 0.01). Their plasma and liver IGF-I concentrations were 30 and 60% lower, respectively, whereas liver IGF-I mRNA abundance was reduced by 50% (p < 0.01). In contrast, neonatal plasma IGF-II and liver IGF-II mRNA concentrations were not significantly affected by the maternal protein malnutrition. Also, the plasma levels of IGFBP were not altered in the growth-retarded pups. Maternal protein restriction did not affect fetal and placental growth, plasma and liver IGF-I levels, and liver IGF-I mRNA abundance in 20-d-old fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Carrier Proteins / metabolism*
  • Embryonic and Fetal Development* / physiology
  • Female
  • Gene Expression Regulation, Developmental / physiology*
  • Gestational Age
  • Insulin-Like Growth Factor Binding Proteins
  • Liver / metabolism
  • Maternal-Fetal Exchange*
  • Pregnancy
  • Prenatal Exposure Delayed Effects
  • Protein-Energy Malnutrition / blood*
  • Rats
  • Rats, Wistar
  • Somatomedins / genetics
  • Somatomedins / metabolism*


  • Carrier Proteins
  • Insulin-Like Growth Factor Binding Proteins
  • Somatomedins