Effect of sodium taurocholate and ethanol on hydrogen ion absorption in rabbit esophagus.

Abstract

The effect of sodium taurocholate (NaTC) (5 mM) and ethanol (5%) on H+ absorption by the esophagus was studied duringin vivo perfusion of rabbit esophagus with solutions of graded concentration of H+ containing either one of these agents. Net ion and volume fluxes, changes in osmolality and PD, histological change, absorption of NaTC or ethanol, were correlated with concentration of acid in the perfusate. There was linear correlation between H+ efflux and luminal H+ concentration except for experiments with NaTC at H+ concentrations higher than 100 mM. Both NaTC and ethanol caused greatly increased rate of removal of H+ from the lumen (accompanied by fall in PD), increased transport of other ions in the direction of their chemical gradients, and much structural disintegration. These changes were more severe with NaTC than with ethanol. In neutral solutions NaTC did not cause changes in PD or net ion fluxes, while ethanol depressed PD and increased net ion fluxes to a lesser extent than when acid was present. NaTC was not absorbed in a neutral solution but absorption increased with acidity. Acidity did not affect ethanol absorption. These data suggest that increased permeability of the esophageal mucosa is the basic mechanism underlying esophagitis. Increased permeability is related to absorption of NaTC or ethanol. The synergistic action of bile or alcohol and acid on the esophageal mucosa is compared to that of aspirin/acid on the gastric mucosa.