Omeprazole Inhibits the Formation of Acid in the Parietal Cell by a Direct Inhibition of the H⁺K⁺ATPase, the Acid Pump of the Stomach

Abstract

H₂-receptor antagonists and antimuscarinic agents are well known antisecretory drugs, exerting their action by blocking cell surface receptors. Recently, substituted benzimidazoles (timoprazole, picoprazole and omeprazole) have been shown to inhibit acid production in vitro in gastric glands from rabbit (1), and acid secretion in vivo in various species including human (2). In the present report of studies on cells isolated from the pig gastric mucosa (3), and on purified membranes containing the H⁺K⁺ATPase, it is shown that the substituted benzimidazole, omeprazole, inhibits the production of gastric acid, probably by direct interaction with the H⁺K⁺ ATPase, the acid pump.