Effect of bombesin, a natural tetradecapeptide, on myoelectrical and mechanical activity of isolated, ex vivo perfused, canine stomach.

Electrical and mechanical activity were recorded from the canine stomach, isolated and ex vivo perfused with homologous blood. The action of Bombesin, a natural tetradecapeptide, was compared with the action of pentagastrin, methacholine and electrical stimulation on the electrical and mechanical activity of this isolated preparation. All drugs used and vagal stimulation resulted in premature control potentials, uncoupling of the normal phase locked pattern of electrical control activity, appearance of response activity and appearance of mechanical reaction. These responses were blocked or decreased by atropine, tetrodotoxin and hexamethonium. It appears that the neural release of acetylcholine is implicated in the mechanism of action of Bombesin gastrointestinal motility.