The localization of a histamine H2-receptor adenylate cyclase system in canine parietal cells and its inhibition by prostaglandins.

A method is described for the preparation of parietal cell-enriched suspensions from dog gastric mucosa. Histamine and E type prostaglandins produce an elevation of cyclic AMP concentration in mixed cell preparations. Parietal cell-rich fractions respond to histamine but only weakly to prostaglandins whilst in fractions virtually free from parietal cells the converse is observed. Prostaglandins which are good antisecretory agents, PGE1, PGE2 and 16,16 dimethyl PGE2 are potent inhibitors of the histamine elevations of cyclic AMP in parietal cell-rich fractions, whilst PFG2alpha shows 1% of their potency. The experiments described support the view that histamine stimulates gastric acid secretion by excitation of an H2-receptor adenylate cyclase system in the plasma membrane of the parietal cell and that acid secretory inhibition by prostaglandins is a result of inhibition of that system.