This study explored the possibility that each surface of the gastric epithelial cell contains ion transport systems contributing to the observed transmucosal potential difference ( Vt). The model proposes that Vt arises from a K+ and Cl– diffusion potential across the submucosal face of the epithelial cells in series with the potential generated by electrogenic transport of H+ and Cl– across the mucosal face. The bio-electric effects of changes in the ionic composition of the bathing media and the tissue composition data were used to test this hypothesis. Vt varied with the log of submucosal K+ at constant Cl– and with the log of submucosal Cl– at constant K+; the sum of the slopes averaged 50 mv. Simultaneous tenfold changes in K+ and Cl– in the submucosal solutions resulted in a 53-mv change in Vt, a reasonable agreement with the theoretical value of 58 mv for a system in which the total electrical conductance is given by the sum of the K+ and Cl– conductances. Alterations in Na+ at either surface had no appreciable effect on Vt. Chemical analysis of gastric mucosae and plasma revealed the predicted pattern of K+ (mucosa) > K+ (extracellular), Na+ (mucosa) < Na+ (extracellular), and Cl– (mucosa) < Cl– (extracellular).
No takes yet. Share an insight, caveat, or question.
Harris et al. (1964) studied this question.