铃蟾肽(Bombesin)对离体灌流大鼠胃的胃泌素、生长抑素、胰升糖素及胃酸释放的影响

本研究用离体大鼠胃灌流技术来观察铃蟾肽对胃-肠激素及胃酸分泌的影响。2×10~(?)mol/L铃蟾肽以0.3ml/min速度作动脉内输注,可刺激胃酸的分泌,自2.50±0.05×10~(-1)增至5.50±1.50×10~(-1)mEq/min,但与外源性五肽胃泌素无协同作用。铃蟾肽引起两次性的门脉中胃泌索及生长抑素的释放,但抑制胰升糖素释放。这三种激素的基础释放率分别为:胃泌素62±8pg,生长抑素5.9±1.1ng,胰升糖素0.40±0.03ng/min;2×10~(-8)mol/L铃蟾肽以0.3ml/min作动脉内输注,胃泌素及生长抑素的峰值分别为1,000±20pg及12.2±2.0ng/min,胰升糖素的最低值为0.17±0.05ng/min,三种激素的反应均与铃蟾肽的浓度成正比。在胃腔流出液中也可测到上述三种激素,但量要少得多。

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.