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. 1984 Jul;82(3):651–657. doi: 10.1111/j.1476-5381.1984.tb10803.x

Inhibition of partially purified K+/H+-ATPase from guinea-pig isolated and enriched parietal cells by substituted benzimidazoles.

W Beil, K F Sewing
PMCID: PMC1987000  PMID: 6146367

Abstract

The cellular and subcellular distributions of adenosinetriphosphatases (ATPases) were examined in guinea-pig gastric mucosal cells. All cell types displayed Mg2+-ATPase and bicarbonate (HCO3-)-stimulated ATPase activity. K+-ATPase was located only in fractions derived from parietal cells. Differential and density-gradient centrifugation of material prepared from parietal cells revealed that K+-ATPase activity was located in a tubulo-vesicular membrane fraction. Enzyme activity was ten fold greater in this fraction than in a crude parietal cell homogenate. The substituted benzimidazoles, omeprazole and picoprazole, inhibited K+-ATPase (IC50 1.8 +/- 0.5 mumol l-1 and 3.1 +/- 0.4 mumol l-1, respectively). Detailed kinetic analysis indicated that these compounds were non-competitive and reversible inhibitors of the enzyme. In contrast cimetidine and verapamil were without effect on the enzyme. The relevance of the inhibition of K+-ATPase to the antisecretory activity of the benzimidazoles, in experimental animals and man, is discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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