Inhibition of acid secretion by bombesin is partly mediated by release of fundic somatostatin.
The effect and mode of action of bombesin on gastric acid secretion was examined in the isolated, luminally perfused mouse stomach. Bombesin caused a concentration-dependent inhibition of basal and histamine-stimulated acid secretion and an increase in somatostatin secretion. Pertussis toxin was used to determine the contribution of somatostatin to the observed inhibition of acid secretion. Previous studies have shown that at a concentration of 125 ng/ml, pertussis toxin reverses completely the inhibition of acid secretion induced by exogenous and endogenous somatostatin. Preincubation of the stomach for 60 min with pertussis toxin (125 and 1250 ng/ml) reversed partially the inhibitory effect of bombesin on basal and histamine-stimulated acid secretion by 51%-59%, implying that bombesin-induced inhibition was partly mediated by release of somatostatin. The residual inhibition may represent a direct effect of bombesin on parietal cells.
Schubert
M L
ML
Department of Medicine, Medical College of Virginia, Richmond.
Hightower
J
J
D000818:Animals; D000863:Antacids; D001839:Bombesin / Q000494:pharmacology*; D005744:Gastric Acid / Q000378:metabolism*; D005748:Gastric Fundus / Q000378:metabolism; D008297:Male; D051379:Mice; D010477:Perfusion; D037342:Pertussis Toxin; D011863:Radioimmunoassay; D013004:Somatostatin / Q000378:metabolism*; D013270:Stomach; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D000863:Antacids; D010566:Virulence Factors, Bordetella; D013004:Somatostatin; D037342:Pertussis Toxin; D001839:Bombesin