Development of the neonatal rat small intestinal barrier to nonspecific macromolecular absorption. II. Role of dietary corticosterone

Pediatr Res. 1992 Jul;32(1):50-7. doi: 10.1203/00006450-199207000-00010.


The role of oral corticosterone (C) in the maturation of the neonatal rat jejunal barrier to the absorption of nonspecific macromolecules was evaluated. This was done by adding C to the diet of rat pups weaned at an early age, 17 d, from maternal milk (MM) to either a protein hydrolysate (PH) or soy (S) artificial formula. Both PH and S are known to cause a delay in small intestinal closure to the absorption of a 40-kD glycoprotein tracer, horseradish peroxidase (HRP), on d 21 of age. C was added to PH and S formulas from d 17 to 21 at 0.26 mumol/L (10 micrograms/dL), a level found in the MM of lactating rat dams, or at 10.29 mumol/L (400 micrograms/dL) (PH + 10C, PH + 400C) (S + 10C, S + 400C). Controls consisted of rat pups fed PH or S without C and animals remaining with the dam on MM. The delay in jejunal closure to HRP on d 21 in both PH- and S-fed pups was prevented by C supplementation at both the higher and lower concentrations. Geometric mean (95% confidence intervals) jejunal HRP absorption in PH + 10C pups was 74 (32,167) IU HRP/mL x cm x min, less than in pups fed PH without C [353 (200,615); p less than 0.05] and indistinguishable from HRP absorption in MM-fed animals [111 (79,154)]. HRP absorption in PH + 400C pups [52 (23,115)] was also less than that in animals fed PH without C (p less than 0.01) and indistinguishable from those fed MM.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

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

MeSH terms

  • Animals
  • Animals, Newborn
  • Corticosterone / administration & dosage
  • Corticosterone / pharmacology*
  • Diet
  • Horseradish Peroxidase / pharmacokinetics
  • Intestinal Absorption / drug effects*
  • Jejunum / drug effects*
  • Jejunum / growth & development
  • Jejunum / physiology
  • Milk
  • Rats
  • Rats, Inbred Strains
  • Weight Gain / drug effects


  • Horseradish Peroxidase
  • Corticosterone