[Cellular localization of adenyl cyclase activated by histamine and prostaglandin E2 in rat gastric mucosa and their role in regulation of gastric secretion]

Abstract

It was shown that cimetidine, the inhibitor of H2-receptors of histamine, does not affect the activation of adenylate cyclase by prostaglandin E2 (PGE2) in rat gastric mucosa homogenate. At the same time cimetidine completely inhibits the stimulating effect of histamine on the adenylate cyclase activity. Using isolated rat gastric cells separated into fractions rich (to 90%) and poor (up to 25%) of parietal cells, it was demonstrated that the prostaglandin-stimulated adenylate cyclase is localized in the non-parietal (presumably mucoid) cells, while the histamine-sensitive one is localized in parietal acid-producing cells. The mechanisms of histamine and PGE2 action are discussed and a scheme of participation of these substances in regulation of gastric secretion is proposed.