下丘脑外侧区注入胃泌素对大鼠胃酸分泌的影响

本工作观察了下丘脑外侧区(LHA)、腹内侧核(VMH)或侧脑室(LCV)注射17肽胃泌素(G17)或五肽胃泌素(G5)对清醒大鼠胃酸分泌的影响。结果表明,将 G17或 G5注入 LHA可引起胃酸分泌明显增加,而将 G5注入 VMH、LCV 或静脉则不影响胃酸分泌;切断迷走神经可以阻断在 LHA 注入 G5引起胃酸分泌增加的效应;在阿托品背景下,将 G5注入 LHA仍能引起胃酸分泌明显增加;静脉注射酚妥拉明,心得安或纳洛酮均不影响 G5对 LHA 刺激胃酸分泌的作用。这些结果提示:LHA 是胃泌素作用的一个特异性部位,由 LHA 发出的冲动可能通过迷走神经内的两种传出纤维引起胃酸分泌,一为胆碱能纤维,另一为非胆碱能非肾上腺素能纤维。

EFFECT OF GASTRIN INJECTED INTO THE LATERAL HYPOTHALAMUS ON GASTRIC ACID SECRETION IN RATS

Effect of pentagastrin (G5) or gastrin (G17) injected into the lateral hypo- thalamus (LHA),the ventromedial hypothalamus (VMH) or the lateral cerebral ventricle (LCV) on gastric acid secretion was observed.In unanesthet(?)zed rats 300 pmol of G5 or G17 injected into LHA increased the gastric acid output significantly,but injection of G5 into VMH,LCV or vein with the same induced no such increase.After vagotomy the increase in gastric secretion induced by G5 injected into LHA was abolished.Under the background of systematic atropine, gastric secretion could still be increased be G5 injected into LHA.Increase of gastric secretion by G5 injected into LHA was also not abolished by systematic administration of phentolamine,propranolol or naloxone. In view of the above results,it is suggested that LHA be a special area in response to gastrin and the effect is mediated by both cholinergic and noncholinergic-non- adrenergic fibers via the vagal nerve.