Central neuromodulation of gastric acid secretion by bombesin-like peptides.
The amphibian skin tetrapeptide bombesin shows potent action in reducing gastric acid secretion by intracerebral ventricular (ICV) administration in rats. In order to establish a relationship between this action and the amino acid composition of the bombesin-like peptides, most of the natural bombesin-like peptides and some synthetic analogues were tested on their ability to reduce gastric acid secretion by ICV administration. The amphibian peptides bombesin, its [Tyr4]-bombesin analogue, alytesin, ranatensin and litorin, and the mammalian peptide GRP significantly reduced gastric acid output 2 hr after peptide administration (p less than 0.01). The data support the following prerequisites for the maximal neuromodulatory role of bombesin-like peptides on gastric secretion: Trp is required at position 8; Gln and His are important at positions 7 and 12, respectively; Leu replacement by Phe, which occurs in the litorin subfamily, modifies the response; and unspecified amino acids or sequences are also involved in the N-terminal region of bombesin-like peptides. Synthetic analogues are currently being tested to confirm and extend these conclusions.
D000595:Amino Acid Sequence; D000818:Animals; D001839:Bombesin / Q000494:pharmacology*; D005750:Gastric Juice / Q000378:metabolism*; D019886:Gastrin-Releasing Peptide; D006863:Hydrogen-Ion Concentration; D008297:Male; D015287:Neurokinin B / Q000031:analogs & derivatives*; D009842:Oligopeptides / Q000494:pharmacology; D010446:Peptide Fragments; D010455:Peptides / Q000494:pharmacology*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects
D009842:Oligopeptides; D010446:Peptide Fragments; D010455:Peptides; C003291:ranatensin; C010212:litorin; D019886:Gastrin-Releasing Peptide; C040794:neuromedin C; D015287:Neurokinin B; C038393:neuromedin B; D001839:Bombesin; D011761:Pyrrolidonecarboxylic Acid