Hirschowitz B I, Fong J
Division of Gastroenterology, University of Alabama, Birmingham 35294.
Am J Physiol. 1990 Jun;258(6 Pt 1):G919-25. doi: 10.1152/ajpgi.1990.258.6.G919.
In four gastric-fistula dogs, selective antral vagotomy markedly reduced the vagal stimulation of gastrin release, thereby defining both the vagal pathway for stimulation of gastrin and the anatomic source of such gastrin release. Despite loss of gastrin response, vagal excitation by 100 mg/kg 2-deoxy-D-glucose (2-DG) produced the same acid and pepsin responses after antral vagotomy as before, but there was an approximately 40% diminished fundic response to pentagastrin, histamine, and synthetic human gastrin, as well as to endogenous gastrin released by graded doses of bombesin. Bethanechol did not reverse the defect, ruling out inadvertent fundic vagal denervation, nor did raising serum gastrin by bombesin alter the response to vagal stimulation by 2-DG. Fundic response to bethanechol was increased by approximately 60%, and the output of gastrin increased at least fivefold after antral vagotomy. Gastrin responses to food were diminished and those to sham feeding were eliminated. Separation of the denervated antral pouch had no additional effect on acid secretion. Vagal stimulation of gastric secretion thus occurs almost exclusively through direct cholinergic effects on the fundus with little or no contribution from antral gastrin. Vagal denervation sensitizes the antrum to cholinergic stimulation.
在四只胃瘘犬中，选择性胃窦迷走神经切断术显著降低了迷走神经对胃泌素释放的刺激，从而确定了刺激胃泌素释放的迷走神经通路以及这种胃泌素释放的解剖学来源。尽管胃泌素反应丧失，但100mg/kg 2-脱氧-D-葡萄糖（2-DG）引起的迷走神经兴奋在胃窦迷走神经切断术后产生的胃酸和胃蛋白酶反应与术前相同，但对五肽胃泌素、组胺和合成人胃泌素以及对不同剂量蛙皮素释放的内源性胃泌素的胃底反应大约降低了40%。氨甲酰甲胆碱不能逆转这种缺陷，排除了无意中切断胃底迷走神经的可能性，用蛙皮素提高血清胃泌素也不会改变对2-DG迷走神经刺激的反应。胃窦迷走神经切断术后，胃底对氨甲酰甲胆碱的反应增加了约60%，胃泌素的分泌量至少增加了五倍。对食物的胃泌素反应减弱，对假饲的反应消失。分离去神经的胃窦袋对胃酸分泌没有额外影响。因此，迷走神经对胃分泌的刺激几乎完全通过对胃底的直接胆碱能作用发生，胃窦胃泌素的贡献很小或没有贡献。迷走神经切断使胃窦对胆碱能刺激敏感。
