Stimulation of dog gastropancreatic hormone release by neuromedin B and its analogues.
The effects on gastrin, insulin, and glucagon release of neuromedin B (NMB), the C-fragment decapeptide of gastrin-releasing peptide-10 (GRP-10), seven analogues replacing amino acid positions 3, 6, and 9, and two C-terminal desamide analogues were examined in conscious dogs using intravenous bolus injection of these peptides study the structure-activity relationship of two bombesin-related peptides identified in mammals. The replacement from valine of position 6 of GRP-10 to threonine effectively reduced the stimulatory potency of these hormone secretions. Removal of the C-terminal amide of NMB and GRP-10 resulted in an almost complete loss of their stimulatory effect on gastrin secretion. [Leu3]GRP-10 elicited the most potent stimulatory activity on three hormone secretions among the analogues including NMB and GRP-10. These results indicate that valine in position 6 of GRP-10 and C-terminal amide of two peptides play an important role in the bioactivities of bombesin family peptides.
D000595:Amino Acid Sequence; D000818:Animals; D001839:Bombesin / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005755:Gastrins / Q000097:blood*; D005934:Glucagon / Q000097:blood*; D007328:Insulin / Q000097:blood*; D015287:Neurokinin B / Q000031:analogs & derivatives*; D009479:Neuropeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D011863:Radioimmunoassay; D013329:Structure-Activity Relationship; D013912:Threonine; D014633:Valine
D005755:Gastrins; D007328:Insulin; D009479:Neuropeptides; D010446:Peptide Fragments; D013912:Threonine; C040794:neuromedin C; D015287:Neurokinin B; C038393:neuromedin B; D005934:Glucagon; D014633:Valine; D001839:Bombesin