| Abstract: | In dispersed mucosal cells from guinea pig stomach cyclic AMP was increased 4-fold by theophylline, 5-fold by prostaglandin E2, and 10- to 15-fold by histamine. Theophylline augmented the increase in cellular cyclic AMP caused by histamine or prostaglandin E1 and the actions of histamine and prostaglandin E1 were additive. Cellular cyclic AMP was not altered by carbachol, gastrin, secretin, vasoactive intestinal peptide, glucagon, insulin or the octapeptide of cholecystokinin. Metiamide or diphenhydramine but not atropine inhibited the increase in cellular cyclic AMP caused by histamine, but did not alter the concentration of cyclic AMP in control cells or in cells incubated with theophylline or prostaglandin E1. |
