Ladabaum U, Koshy S S, Woods M L, Hooper F G, Owyang C, Hasler W L
Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA.
Am J Physiol. 1998 Sep;275(3):G418-24. doi: 10.1152/ajpgi.1998.275.3.G418.
Nausea and gastric dysrhythmias occur in conditions associated with gastric distension. The roles of distal and proximal gastric mechanoreceptors in these responses are unexplored. Because antral distension induces vomiting in animals and antral and fundic vagal afferent discharges differ, we hypothesized that distal gastric distension in humans leads to greater symptomatic and dysrhythmic responses than proximal distension. Symptoms and electrogastrograms were recorded in healthy humans during distal and proximal gastric distension with a barostat. Distal but not proximal distension induced nausea and a 747 +/- 250% increase in dysrhythmic power (P < 0.05), responses not affected by granisetron, indomethacin, or atropine, agents that block dysrhythmias in other settings. In the distal stomach, bloating and pain developed at lower pressures (P < 0.05) not modified by granisetron, and compliance was significantly lower (P < 0.05). In conclusion, gastric mechanoreceptor activation in the less-compliant distal stomach produces nausea and dysrhythmias via non-5-hydroxytryptamine3 (5-HT3), non-prostaglandin-dependent, and noncholinergic pathways. Distal mechanoreceptor activation induces greater bloating and pain than proximal mechanoreceptor activation via 5-HT3-independent pathways.
恶心和胃节律失常发生在与胃扩张相关的情况下。胃远端和近端机械感受器在这些反应中的作用尚未得到探索。由于胃窦扩张会诱发动物呕吐，且胃窦和胃底迷走神经传入放电不同，我们推测人类胃远端扩张比近端扩张会导致更强烈的症状性和节律失常反应。在健康人体中，使用恒压器对胃远端和近端进行扩张时，记录症状和胃电图。胃远端而非近端扩张会诱发恶心，且节律失常功率增加747±250%（P<0.05），这些反应不受格拉司琼、吲哚美辛或阿托品的影响，而这些药物在其他情况下可阻断节律失常。在胃远端，腹胀和疼痛在较低压力下出现（P<0.05），不受格拉司琼影响，且顺应性显著降低（P<0.05）。总之，顺应性较低的胃远端机械感受器激活通过非5-羟色胺3（5-HT3）、非前列腺素依赖性和非胆碱能途径产生恶心和节律失常。与近端机械感受器激活相比，远端机械感受器激活通过不依赖5-HT3的途径诱发更强烈的腹胀和疼痛。
