Anion exchange in oxyntic cell apical membrane: Relationship to thiocyanate inhibition of acid secretion

J. M. Wolosin, J. G. Forte

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

The effects of SCN- on H+-accumulation by inside-out gastric vesicles derived from the apical membrane of secreting oxyntic cells are reported. SCN- inhibited the formation of pH gradients in Cl- and isethionate media. In Cl-, the concentration of SCN- required to achieve a certain degree of inhibition of H+ uptake (or dissipation of preformed gradients) was increased with the increase in Cl- concentration, indicating some competitive phenomena between these anions. Comparison of the rates of dissipation of similar pH gradients achieved in Cl-vs. isethionate suggested the existence of a fast Cl-/SCN- exchange. In addition, direct isotopic fluxes confirmed the existence of rapid anion exchange and K-salt transport for both Cl- and SCN-. The rates of anion-exchange and K-salt transport were of similar magnitude, and the rates for SCN- in either countertransport against Cl- or cotransport with K+ were twice as fast as the equivalent values for Cl-. These mediated pathways in the apical membrane provide the possible means for rapid access of SCN- to the acidic canalicular spaces of the oxyntic cell that is implicit in recent proposals to explain SCN- inhibition of gastric HCl secretion.

Original languageEnglish
Pages (from-to)261-268
Number of pages8
JournalJournal of Membrane Biology
Volume76
Issue number3
DOIs
StatePublished - Oct 1983
Externally publishedYes

Keywords

  • (H+K)-ATPase
  • HCl secretion
  • anion transport
  • apical membrane
  • gastric mucosa
  • gastric secretion

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