Effect of histamine receptor antagonists on bile damage to the gastric mucosa of canine

SUMMARY The net ionic fluxes ofH+ and Na+ were examined in Heidenhain pouches during damage with sodium taurocholate solution. The increase in ionic flux which occurred with taurocholate could be prevented in animals given H1 and H2 histamine antagonists in combination. The results suggest that histamine mediates changes in the transmucosal ionic flux produced by bile acid. Although it is well recognised that damaged gastric mucosa becomes more permeable to both hydrogen and sodium ions, the mechanisms involved are poorly understood. Davenport (1972) suggested that the surface lipoprotein layer of gastric epithelium was the major constituent of themucosal barrier, and disruption of this layer facilitated back diffusion of hydrogen ions which in turn caused release of histamine from mast cells. Support for this hy-pothesis was provided by Johnson (1966, 1968) who used the pylorus-ligated stomach in rats t