title: Transepithelial transport of putrescine across monolayers of the human intestinal epithelial cell line, Caco-2.
abstract: OBJECTIVE
  To study the transepithelial transport characteristics of the polyamine putrescine in human intestinal Caco-2 cell monolayers to elucidate the mechanisms of the putrescine intestinal absorption.
  
  
  METHODS
  The transepithelial transport and the cellular accumulation of putrescine was measured using Caco-2 cell monolayers grown on permeable filters.
  
  
  RESULTS
  Transepithelial transport of putrescine in physiological concentrations (> 0.5 mM) from the apical to basolateral side was linear. Intracellular accumulation of putrescine was higher in confluent than in fully differentiated Caco-2 cells, but still negligible (less than 0.5%) of the overall transport across the monolayers in apical to basolateral direction.EGF enhanced putrescine accumulation in Caco-2 cells by four fold, as well as putrescine conversion to spermidine and spermine by enhancing the activity of S adenosylmethionine decarboxylase. However, EGF did not have any significant influence on putrescine flux across the Caco-2 cell monolayers. Excretion of putrescine from Caco-2 cells into the basolateral medium did not exceed 50 picomoles, while putrescine passive flux from the apical to the basolateral chamber, contributed hundreds of micromoles polyamines to the basolateral chamber.
  
  
  CONCLUSIONS
  Transepithelial transport of putrescine across Caco2 cell monolayers occurs in passive diffusion, and is not influenced when epithelial cells are stimulated to proliferate by a potent mitogen such as EGF.
authors.affiliation: Medizinische Klinik II, J.W.Goethe Universität, Theodor Stern Kai 7, D.60590 Frankfurt, Germany. milovic@em.uni-frankfurt.de
authors.forename: V
authors.initials: V
authors.lastname: Milovic
authors.forename: L
authors.initials: L
authors.lastname: Turchanowa
authors.forename: J
authors.initials: J
authors.lastname: Stein
authors.forename: W F
authors.initials: WF
authors.lastname: Caspary
mesh_terms: D001692:Biological Transport; D018938:Caco-2 Cells; D004815:Epidermal Growth Factor; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology*; D011700:Putrescine / Q000378:metabolism*; D011994:Recombinant Proteins
chemical_list: D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D011700:Putrescine