Effect of short chain fatty acids on paracellular permeability in the caco-2 model of intestinal epithelium. Mariadason, John M., David H. Barkla, Peter R. Gibson. UNIVERSITY OF MELBOURNE DEPARTMENT OF MEDICINE, THE ROYAL MELBOURNE HOSPITAL, and MONASH UNIVERSITY, DEPARTMENT OF ANATOMY, VICTORIA, AUSTRALIA
APStracts 3:0215G, 1996.
Control of paracellular permeability in the colonic epithelium is fundamental to its functional competence. This study examines the relationship between physiologically relevant short chain fatty acids (SCFAs) and paracellular permeability using the Caco-2 cell line model. Butyrate induced a concentration dependent, reversible increase in trans-epithelial resistance (TER), that was maximal after 72 hours. Butyrate (2 mM) increased TER by 299 +/- 69% (mean +/- sem, n=5, P<0.05, t test) and reduced mannitol flux to 52 +/- 11% (P<0.05) of control. The effect of butyrate was dependent upon protein synthesis and gene transcription, but not dependent on its oxidation or activation of cAMP. The other SCFAs propionate and acetate, also induced a concentration dependent increase in TER. Butyrate's effect parallelled changes in cellular differentiation as alkaline phosphatase activity, carcinoembryonic antigen expression (CEA), and dome formation were increased. Furthermore, other differentiating agents (DMSO and retinoic acid) also increased TER. Thus, SCFAs reduce paracellular permeability in the Caco-2 cell line, possibly by promotion of a more differentiated phenotype. If such an effect occurs in vivo it may have ramifications for the biology and pathobiology of colonic mucosa.

Received 28 February 1996; accepted in final form 26 September
1996.
APS Manuscript Number G77-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996