A SINGLE MEAL ELICITS REGIONAL CHANGES IN BOMBESIN-LIKE PEPTIDE LEVELS IN THE GUT AND BRAIN

Several studies have demonstrated that exogenous bombesin (BN) elicits a potent satiety effect when administered centrally or systemically. It has been suggested that BN-like peptides may play a physiological role in the control of food intake. The objective of the present study was to determine whether the levels of endogenous BN-like peptides change in response to a meal. All rats were food deprived overnight for a 12 h period. Half the animals were then allowed to feed for 35 min (postprandial group) and the remainder formed the preprandial group. Regions of the brain (hypothalamus, cerebellum, medulla, pons, neocortex, hippocampus, olfactory bulbs, striatum, midbrain and pituitary), gut (oesophagus, fundus, antrum, duodenum, jejunum, ileum, colon) and adrenal glands were analyzed for BN-like peptide levels using radioimmunoassay. Our results indicate significant increases in the levels of BN-like peptides in the hypothalamus and hippocampus, as well as in the antrum of the stomach, after food ingestion. These results are the first to demonstrate the activation of endogenous BN-like peptide mechanisms in response to ingestion. These rapid alterations in peptide levels may support the contention that BN-like peptides play a physiological role in the regulation of ingestive behavior.