[Effects of bombesin on gastrin, somatostatin, glucagon and acid secretion from isolated rat stomach in vitro].

Effects of bombesin on the secretion of gastric acid and gastro-intestinal hormones were investigated in isolated perfused rat stomach. Bombesin (intra-arterial, 2 x 10(-10) mol/L, 0.3 ml/min) stimulated gastric acid secretion from basal 2.50 +/- 0.05 x 10(-1) to 8.40 +/- 1.50 x 10(-1) mEq/min (P less than 0.001). Exogenous addition of pentagastrin did not potentiate this effect of bombesin. Bombesin induced twice releasing of gastrin and somatostatin in portal effluent but inhibited glucagon secretion. The basal releasing rates of these three hormones were 62 +/- 8 pg, 5.9 +/- 1.1 ng, and 0.40 +/- 0.03 ng/min respectively. The peak values of gastrin and somatostatin during bombesin stimulation were 1000 +/- 20 pg and 12.2 +/- 2.0 ng/min respectively, while the nadir value of glucagon was 0.17 +/- 0.05 ng/min. All three responses were dose-dependent. These three hormones were all detectable, albeit at much lower concentrations in the pyloric effluent perfusate than they were in the portal effluent.