title: Enterally but not parenterally administered Phaseolus vulgaris lectin induces growth and precocious maturation of the gut in suckling rats.
abstract: BACKGROUND
  The lectin, phytohemagglutinin (PHA) has been shown to induce growth and functional maturation of the gastrointestinal (GI) tract in suckling rats.
  
  
  OBJECTIVE
  To investigate the effect of the administration route, and whether enteral exposure to PHA was necessary to induce functional maturation.
  
  
  METHODS
  Fourteen-day-old rats were daily administered PHA via orogastric feeding (0.05 mg PHA/g BW) or via subcutaneous injection (0.05 or 0.005 mg PHA/g BW) for 3 days, while the controls received saline orogastrically. At 17 days of age, organ weight, intestinal and pancreatic function, and plasma corticosterone levels were analyzed. Moreover, 14-days old pups receiving a single dose of PHA, enterally or parenterally, were sacrificed after 12 h and examined for organ PHA binding using immunohistochemistry.
  
  
  RESULTS
  Enteral PHA exposure resulted in PHA binding in the epithelial lining of the small intestine, increased gastrointestinal growth, reduced intestinal macromolecular absorption, altered the disaccharidase expression towards an adult-like pattern, and increased the pancreatic protein and trypsin contents. In contrast, parenteral PHA exposure (high dose) resulted in PHA-binding in extra-intestinal organs, increased liver and spleen weight, and decreased thymus weight. Moreover, the intestinal maltase activity increased moderately, and the transfer of BSA to blood plasma was partially reduced. Both PHA treatments led to elevated plasma corticosterone levels.
  
  
  CONCLUSIONS
  These results demonstrated that enteral exposure to PHA was necessary to induce the precocious maturation of the GI tract and the pancreas, while parenteral administration affects the extra-intestinal organs. Furthermore, the enteral effects were probably not mediated via a corticosteroid dependent pathway.
authors.affiliation: Department of Cell and Organism Biology, Animal Physiology, Lund University, Lund, Sweden. Ann.Linderoth@cob.lu.se
authors.forename: Ann
authors.initials: A
authors.lastname: Linderoth
authors.forename: Olena
authors.initials: O
authors.lastname: Prykhod'ko
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Pierzynowski
authors.forename: Bjorn R
authors.initials: BR
authors.lastname: Westrom
mesh_terms: D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development*; D001835:Body Weight; D003345:Corticosterone / Q000097:blood; D004750:Enteral Nutrition; D041981:Gastrointestinal Tract / Q000201:enzymology / Q000254:growth & development*; D007150:Immunohistochemistry; D009929:Organ Size; D009928:Organ Specificity; D010179:Pancreas / Q000254:growth & development; D010288:Parenteral Nutrition; D010835:Phytohemagglutinins / Q000008:administration & dosage* / Q000032:analysis / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010835:Phytohemagglutinins; D003345:Corticosterone