Distinct receptors mediate gastrin-releasing peptide and neuromedin beta-induced delay of gastric of liquids in rats.
The present study was carried out to define which bombesin receptors are involved in the delay of gastric emptying induced by bombesin-like peptides. Adult male rats were fitted with gastric and jugular vein cannulas. Gastric emptying was determined 5 min after a 3-ml intragastric load of 0.9 M NaCl using phenol red as a marker. Mammalian bombesin-like peptides gastrin-releasing peptide-10 and neuromedin B both induced a delay of gastric emptying. When [Phe6]bombesin-(6-13)-methyl ester, a selective antagonist of the gastrin-releasing peptide-preferring subtype of bombesin receptors, was injected 5 min before the agonists, the effect of gastrin-releasing peptide-10 was competitively inhibited, whereas that of neuromedin B remained unaffected. Our results indicate that gastrin-releasing peptide-10 and neuromedin B delay gastric emptying by acting on distinct receptors in rats, in vivo.
Varga
G
G
Institute of Experimental Medicine, Budapest, Hungary.
Liehr
R M
RM
Scarpignato
C
C
Coy
D H
DH
D000818:Animals; D001839:Bombesin / Q000819:agonists* / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005746:Gastric Emptying / Q000187:drug effects*; D008297:Male; D015287:Neurokinin B / Q000031:analogs & derivatives* / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018004:Receptors, Bombesin / Q000819:agonists
D010446:Peptide Fragments; D018004:Receptors, Bombesin; C071101:bombesin (6-13), Phe(6) methyl ester-; C040794:neuromedin C; D015287:Neurokinin B; C038393:neuromedin B; D001839:Bombesin