REGIONAL DIFFERENCES IN THE EFFECT OF CHOLERA-TOXIN AND ENTEROTOXIGENIC ESCHERICHIA-COLI INFECTION ON ELECTROLYTE AND FLUID TRANSPORT IN THE PORCINE SMALL-INTESTINE

The regional differences in secretory and absorptive responses to chol era toxin (CT) and to infection by enterotoxigenic Escherichia roll (E TEC), producing heat-stable enterotoxins,were studied in the porcine s mall intestine. Proximal, mid and distal small intestine from newly we aned piglets were used. Na+ and Cl- fluxes and electrical parameters i n CT stimulated and ETEC-infected intestine mere measured by the Ussin g chamber technique In addition,CT-induced fluid accumulation in ligat ed loops was measured. CT induced fluid accumulation, which was highes t in the proximal segment and decreased in the aboral direction of the small intestine. In addition, CT induced a net Cl- secretion in the p roximal and mid segments, while net Nai absorption was reduced only in the proximal segment. The ETEC-infected intestine showed a net increa se in Cl- secretion in the proximal part and abolished the net Na+ abs orption in the distal segment. These results demonstrate segmental dif ferences in the epithelial transport responses to enterotoxin from Vib rio cholerae and to ETEC infection. This needs to be taken into consid eration in relation to oral rehydration studies.