Vagal inhibition of gastric acid secretion: evidence for cholecystokinin as the inhibitory transmitter in the mouse stomach

Abstract

In the mouse isolated stomach preparation, electrical stimulation of vagal preganglionic fibres activated cholinergic excitatory pathways and noncholinergic inhibitory pathways to the gastric glands. Both were blocked by hexamethonium suggesting that there is at least one nicotinic synapse in each. The inhibitory vagal response was blocked by dibutyryl cyclic GMP, an established cholecystokinin antagonist which abolished cholecystokinin-mediated inhibition of acid secretion. It is suggested that there are direct inhibitory vagal pathways to the gastric glands and that cholecystokinin may be the inhibitory transmitter.