Short chain fatty acids but not lactate or succinate stimulate mucus release in the rat colon

Background: Short chain fatty acids (SCFAs) affect various intestinal funct ions. Mucus is an important physiological component of the intestinal mucos al barrier. However, the effect of SCFAs or other organic acids on the inte stinal mucus release is poorly understood. The aim of this study was to inv estigate whether lumen SCFA stimulates mucus release into the rat colon. Me thods: A solution of SCFA. lactate or succinate was-infused into the colon of anesthetized rats, and we then measured the hexose content of the efflue nt. We also examined the influence of cholinergic antagonists on the effect s of SCFA. Results: A SCFA mixture (75 mM acetate, 35 mM propionate and 20 mM butyrate) or individual SCFAs (130 mM) increased the mucus release into the colon in a similar manner. The individual SCFAs, but not lactate or suc cinate, stimulated colonic mucus secretion in similar concentration-depende nt manners. Butyrate stimulated colonic mucus secretion at 20 mM, but aceta te, propionate, lactate and succinate at this concentration did not. Pretre atment with an anti-cholinergic agent diminished the stimulatory effects of SCFAs on mucus secretion. Conclusions: Lumen SCFAs, but not lactate or suc cinate, stimulate mucus release from the rat colon via a cholinergic nerve mechanism. (C) 2000 Elsevier Science Inc. All rights reserved.