Binding and the effect of the red kidney bean lectin, phytohaemagglutinin, in the gastrointestinal tract of suckling rats

Br J Nutr. 2006 Jan;95(1):105-15. doi: 10.1079/bjn20051612.

Abstract

Enteral exposure of suckling rats to phytohaemagglutinin (PHA) has been shown to induce growth and precocious functional maturation of the gastrointestinal tract. The aim of the present study was to explore the mechanism of this action. Suckling rats, 14 d old, were fed a single dose of PHA (0.05 mg/g body weight) or saline. The binding of PHA to the gut epithelium and its effect on the morphology and functional properties of the gut and pancreas were studied up to 3 d after treatment. Initially, at 1-24 h, the PHA bound along the gut mucosal lining, resulting in disturbed gut morphology with villi shortening and rapid decreases in disaccharidase activities and macromolecular absorption capacity. During a later phase, between 1 and 3 d, the PHA binding had declined, and an uptake by enterocytes was observed. An increase in crypt cell proliferation and gut growth became evident during this period, together with a functional maturation, as indicated by increases in disaccharidase (maltase and sucrase) activities and the low macromolecular absorption capacity. Pancreas growth also increased, as did its content of digestive enzymes. We conclude that enteral exposure to PHA in suckling rats temporarily causes mucosal disarrangement and functional impediment of the gut, which may be explained by binding to and disruption of the gut mucosa and a two-fold increase in the plasma corticosterone concentration. These findings may lead to a better understanding of the role of diet in gastrointestinal maturation and may constitute a basis for the treatment of mammals having an immature gut.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Suckling
  • Biomarkers / blood
  • Corticosterone / blood
  • Endocytosis / physiology
  • Epithelial Cells / drug effects
  • Epithelial Cells / metabolism
  • Gastric Mucosa / metabolism
  • Gastrointestinal Tract / drug effects*
  • Gastrointestinal Tract / physiology
  • Immunohistochemistry / methods
  • Insulin / blood
  • Intestinal Absorption / physiology
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism
  • Intestine, Small / anatomy & histology
  • Intestine, Small / drug effects
  • Intestine, Small / metabolism
  • Intestines / drug effects
  • Intestines / physiology
  • Organ Size / drug effects
  • Organ Size / physiology
  • Pancreas / drug effects
  • Pancreas / physiology
  • Phytohemagglutinins / metabolism
  • Phytohemagglutinins / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Stomach / drug effects
  • Weight Gain / drug effects
  • Weight Gain / physiology

Substances

  • Biomarkers
  • Insulin
  • Phytohemagglutinins
  • Corticosterone