Acid secretion and mucosal cyclic nucleotide content of the guinea pig isolated stomach during bethanechol stimulation.

Acid secretion and mucosal cyclic AMP and cyclic GMP content of guinea pig isolated stomach preparations were measured at various times after stimulation with bethanechol (1.7 X 10(-5) M). Significant increases in acid secretion were observed without changes in cyclic nucleotides. Pre-incubation of the tissues with theophylline (10(-3) M) increased acid secretion and nucleotide content. An additional increase in acid secretion was then obtained with bethanechol in these tissues but without further change in nucleotides. Carbachol (30 micrograms/kg) administered by interperitoneal injection to conscious guinea pigs also failed to change gastric mucosal cyclic nucleotides when the animals were sacrificed 15 min later. These results are discussed in relation to the mechanisms of cholinergic stimulation of gastric acid secretion.