REGIONAL DIFFERENCES IN THE EFFECT OF MUCOSAL GLUCOSE AND AMINO-ACIDSON ION-TRANSPORT IN NORMAL AND CHOLERA TOXIN-STIMULATED PORCINE SMALL-INTESTINE

Background: This study explores regional differences in the response t o mucosal D-glucose and L-amino acids in both normal intestine and int estine stimulated with cholera toxin. Methods: Proximal, mid and dista l small intestines from 6- to 8-week-old pigs were bathed in Ussing ch ambers with a buffer containing 15 mM serosal glucose, and the effect of adding a cocktail giving luminal chamber concentrations of 15 mM D- glucose and 20 mM of each L-alanine, L-proline, L-lysine, L-phenylalan ine, and L-glutamine on transmucosal Na+ and Cl- transport was measure d. Results: In all segments of both normal and cholera toxin-treated i ntestine, electrogenic Na+ and electroneutral NaCl absorption were pro moted. No significant differences in the net increase of Na+ and Cl- a bsorption between normal and cholera toxin-stimulated intestine were p resent. Under both conditions no segmental differences were present in the stimulated Cl- absorption, describing identical capacity for stim ulated electroneutral NaCl absorption. In contrast the electrogenic Na + absorption was, compared to the proximal part, doubled in the mid an d distal parts under both conditions. Conclusions: We conclude that mu cosal D-glucose and L-amino acids stimulate electroneutral NaCl and el ectrogenic Na+ absorption to the same degree in normal and cholera tox in-treated small intestine. There Is no segmental difference in stimul ated electroneutral NaCl absorption, while electrogenic Na+ absorption is highest in mid and distal parts.