Injection into the CSF of bombesin and peptides related to the bombesin family induces a robust inhibition of the gastric acid secretion stimulated by histamine, gastrin, or vagal activation in rats, rabbit, cats, and dogs. Bombesin is more potent than a number of bombesin analogs or unrelated peptides. Its action is CNS mediated and responsive sites occur in both forebrain and hindbrain. The most sensitive site is located in the nucleus ambiguus; other responsive sites include the paraventricular nucleus and the dorsal vagal complex. The inhibition of acid secretion occurs independently from changes in gastrin release, requires the integrity of spinal pathways, and appears to be elicited by an alteration of sympathetic nerve activity to both the adrenals and the stomach and a decrease of parasympathetic outflow to the stomach. Central injection of bombesin also influences other gastric secretory functions. It elicits an increase in gastric mucus and in bicarbonate and gastrin secretion, and it inhibits pepsin secretion and experimental gastric and duodenal ulcers in rats. Much less is known regarding the brain sites and mechanisms of action for these effects than for the effects on gastric acid secretion. The profound CNS actions of bombesin to alter gastric secretion in various animal species, along with the presence of bombesin-immunoreactive terminals and receptors in brain areas involved in regulation of gastric function, suggest a possible role of endogenous bombesin-like peptides in the CNS regulation of gastric secretion and maintenance of mucosal integrity. Recently developed bombesin antagonists will be useful in assessing the physiological relevance of bombesin in the CNS. The robust CNS-mediated alterations of gastric secretion in response to central injection of bombesin and the complexity of the neurohumoral pathways and mechanisms involved make bombesin one of the most useful tools for elucidating the intricacies of the brain-gut interaction.
|Original language||English (US)|
|Number of pages||11|
|Journal||Annals of the New York Academy of Sciences|
|State||Published - 1989|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)