BOMBESIN-STIMULATED ACETYLCHOLINE-RELEASE FROM MYENTERIC PLEXUS NEURONS

The ability of bombesin to stimulate acetylcholine release from guinea pig myenteric plexus neurons was studied using a primary neuronal culture system. Bombesin caused dose-dependent increases in [3H]acetylcholine (ACh) release from guinea pig myenteric plexus neurons. ACh release in response to 0.5 mM bombesin (160 ± 12% of control) was blocked by exposure to a calcium-free medium (116 ± 13%) by nifedipine (101 ± 11%) and by omega conotoxin (107 ± 10%). Bombesin-stimulated ACh release was inhibited the protein kinase C inhibitor, H7, but was not affected by inhibitors of the cAMP signaling pathway. Interactions with inhibitory neuropeptides was implied by sensitivity of bombesin-stimulated ACh release to neuropeptide Y and galanin. The findings suggest that bombesin activation of protein kinase C in myenteric neurons resuits in increased acetylcholine release. © 1993 Academic Press. All rights reserved.