RESPONSES OF PLASMA CYCLIC NUCLEOTIDES AND GUT HORMONE AFTER ORAL INGESTION OF CHOLERA TOXIN IN MICE

Abstract

The pathophysiologic aspects of gut hormones, as related to diarrhea induced by cholera toxin were investigated. After cholera toxin had been given by gavage, changes of intestinal fluid retention, hematocrit, plasma cyclic nucleotides and of plasma gut hormone levels were measured in order to assess the effects of the cholera toxin. Radioimmunoassay methods were used. The intestinal fluid retention was remarkable and concomitant with increasing hematocrit values. The levels of plasma c-AMP increased significantly, yet there were no changes in plasma c-GMP. The levels of plasma gastrin increased slightly and levels of substance P and gut GLI (enteroglucagon) increased significantly, but levels of plasma secretin, glucagon immunoreactivity (GI) and contrary to expectation, VIP were unchanged.
These results suggest that plasma gut GLI increases following diarrhea, that intestinal substance P plays an important role in the mechanism of cholera plus diarrhea, and that c-AMP levels have little influence on this effect.