离体大鼠胃扩张时胃泌素生长抑素分泌的变化及机制探讨

目的：探讨胃扩张时胃泌素，生长抑素分泌的变化以及胃内神经，体液调节机制在其中的可能作用。方法：用带血管灌流的离体大鼠胃，从胃腔灌注生理盐水造成胃扩张模型，经血管注入神经递质或相应拮抗剂等，观察上述指标变化。结果：胃扩张引起容量依赖性的胃泌素分泌减少及生长抑素分泌增加；从胃动脉注入河豚毒或阿托品，上述效应分别被阻断５０％和４０％Ａ左右；注入生长抑素拮抗剂ｃｙｃｏ「７－ａｍｉｎｏｈｅｐｔａｎｏｙｌ－Ｐ

Role of somatostatin and cholinergic mechanisms of gastrin release regulation in isolated rat stomach during gastric distention

AIM:To examine the effect of graded distention of isolated rat stomach on the release of gastrin and somatostatin(SS), and the possible intragastric mechanisms.METHODS and RESULTS:Graded gastric distention by 5, 10, 15 mL saline for 20 minutes caused a significant volume-dependent decrease of gastrin release and increase of SS release. In response to 10 mL distention, infusion of axonalblocker TTX(10 6 mol/L) and cholinergic blocker atropine (10 7 mol/L) attenuated a decrement of gastrin release by 50% and an increment of SS by 40%, respectively. The SS antagonist (SS-A) cyclo [7-aminohepanoyl-Phe-D-Trp-Lys-Thr(Bzl)](10 6 mol/L) attenuated the inhibition of gastrin release by 60%. Furthermore, combined infusion of SS-A and atropine completely abolished distention induced inhibition of gastrin release.CONCLUSIONS:Distention of isolated rat stomach stimulates SS release via cholinergic and non-cholinergic TTX-insensitive pathways. But SS also intragastric cholinergic pathways are responsible for the distention-induced inhibition of gastrin release.