Effects of salicylate and bile salt on ion transport by isolated gastric mucosa of the rabbit.

The effects of luminal addition of salicylate and taurocholate on ion transport by fundic mucosa were examined in vitro using isotopic and pH stat techniques. Salicylate, 3 mM, did not alter, but 20 mM caused a 40% decrease in, the acid secretory rate. Taurocholate, 20 mM, caused a transient, apparent cessation of acid secretion followed by stimulation. Salicylate, 3 or 20 mM, increased Na+ but not Cl- permeability at luminal pH 7. At luminal pH 4, however, salicylate increased Cl- in addition to Na+ and H+ permeability. Taurocholate, 10 or 20 mM, increased both cation and anion permeability at pH 7 and 4. Addition of salicylate or taurocholate results in stimulation of net Na+ transport. While salicylate and taurocholate increase cation permeability at pH 7, they have differing effects on acid secretion and anion permeability. The data suggest that salicylate and taurocholate alter cation permeability by different mechanisms and are consistent with the concept that enhanced diffusion of H+ into the tissue causes a nonspecific alteration in the permeability pathway.