The effect of sodium taurocholate on the permeability of antral and fundic gastric mucosa

Abstract

The effect of sodium taurocholate on the permeability of antral and fundic gastric mucosae was investigated by using an in vitro preparation of rabbit antral and fundic gastric mucosae mounted in Ussing chambers and perfused with a physiological bicarbonate solution at 37°C. Permeability was measured by the transmucosal flux of [ 14C]erythritol, a water-soluble, nonlipid-soluble molecule. Twenty millimolar sodium taurocholate at pH 7.4 in the mucosal solution did not increase the flux of erythritol across fundic tissue when compared to controls but did cause a significant fall in tissue resistance, whereas 20 m M sodium taurocholate at pH 7.4 in the mucosal solution of antral tissue increased the flux of erythritol after 30 min when compared with controls, 2.23 ± 0.43 and 0.68 ± 0.14 pmol/cm 2/sec, respectively, and caused a statistically significant fall in tissue resistance. At pH 2.5 2 m M sodium taurocholate in the mucosal solution increased the flux of erythritol across fundic tissue when compared with controls, 5.73 ± 1.03 and 0.82 ± 0.15 pmol/cm 2/sec, respectively, and statistically reduced tissue resistance. In antral tissue 2 m M sodium taurocholate at pH 2.5 increased erythritol flux across antral tissue when compared with controls, 13.97 ± 5.15 and 1.38 ± 0.34 pmol/cm 2/sec, respectively, and statistically reduced tissue resistance. In treated mucosa the slope of the regression of flux against time was significantly greater in antral than fundic tissue, indicating greater antral mucosal permeability. At both high and low pH the increase in physical permeability caused by taurocholate is greater in antral than fundic mucosa.