title: Glutamine reduces phorbol-12,13-dibutyrate-induced macromolecular hyperpermeability in HT-29Cl.19A intestinal cells.
abstract: BACKGROUND
  Loss of mucosal integrity is associated with intestinal hyperpermeability, which may be inhibited by glutamine. The nature of this effect is unknown. The effect of glutamine on protein kinase C (PKC)-mediated hyperpermeability in HT-29Cl.19A intestinal cells was studied.
  
  
  METHODS
  Confluent monolayers of HT-29C1.19A cells were cultured on permeable filters and mounted in Ussing chambers for permeability studies. Apical to basolateral transepithelial permeability for intact horseradish peroxidase (HRP) was determined. Phorbol-12,13-dibutyrate (PDB) was used to activate PKC-mediated hyperpermeability, and the effect of glutamine (0.6 mmol/L) was studied.
  
  
  RESULTS
  Two hours of PDB stimulation increased the HRP flux, reaching five times control values after 4 hours. Bilateral exposure to glutamine for 4 hours reduced PDB-induced hyperpermeability (37%). Preincubation with glutamine 2 hours before PDB stimulation showed an earlier and greater effect (3 hours, 43%; 4 hours, 50%). This bilateral effect of glutamine was mimicked by separate apical exposure. Basolateral exposure alone had no effect.
  
  
  CONCLUSIONS
  Glutamine rapidly reduced the PKC-mediated hyperpermeability for HRP in HT-29Cl.19A intestinal cells. The dependency on apical exposure suggests that glutamine may be more effective when delivered by the enteral route.
authors.affiliation: Department of Surgery, Free University Hospital, Amsterdam, Institute of Neurobiology, Faculty of Biology, University of Amsterdam, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Kouznetsova
authors.forename: P B
authors.initials: PB
authors.lastname: Bijlsma
authors.forename: P A
authors.initials: PA
authors.lastname: van Leeuwen
authors.forename: J A
authors.initials: JA
authors.lastname: Groot
authors.forename: A P
authors.initials: AP
authors.lastname: Houdijk
mesh_terms: D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004847:Epithelial Cells / Q000648:ultrastructure; D005973:Glutamine / Q000378:metabolism / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D007422:Intestines / Q000648:ultrastructure*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism
chemical_list: D005973:Glutamine; D015240:Phorbol 12,13-Dibutyrate; D006735:Horseradish Peroxidase; D011493:Protein Kinase C