Relation between transmucosal potential difference, ionic flux, and the intraluminal supply of H+ in the ferret...

To investigate the relation between gastric transmucosal potential difference, ionic flux, and the intraluminal concentration of H+, test solutions containing various concentrations of HCl were instilled into ferret stomachs both before and after exposure to various doses of acetic acid. The changes in ionic composition of the test solution were determined and the transmucosal potential difference was recorded throughout each experiment. The results showed that after exposure to the organic acid (1) ionic flux was proportional to the concentration of acetic acid used and was a direct function of the concentration of H+ within the lumen, and (2) the decrease in transmucosal potential difference was proportional to the concentration of acetic acid used but did not appear to be related to the subsequent magnitude of ionic flux. It is suggested that the decrease in gastric transmucosal potential difference that follows exposure of the gastric mucosa to an organic acid is a measure of the increase in mucosal permeability, whereas the subsequent ionic movements are governed by the concentration of H+ within the gastric lumen.