Björnsson E S, Chey W D, Ladabaum U, 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):G498-505. doi: 10.1152/ajpgi.1998.275.3.G498.
Colonic motor function is modulated by extended and local neural reflexes involving unknown mediators. To test the role of serotonin (5-HT3) pathways, increases in colonic tone during antral distension and duodenal lipid perfusion (gastrocolonic responses) and changes in orad and caudad colonic tone in response to local colonic distension (peristaltic reflex) were measured after double-blind granisetron (10 microg/kg) or placebo infusion in healthy human volunteers. Antral distension evoked increases in colonic tone, which were blunted by granisetron (P < 0.05) without effects on antral compliance. Intraduodenal lipid perfusion also evoked increased colonic tone, which was reduced by granisetron (P < 0.05). In contrast, orad colonic contractions and caudad relaxations and contractions during colonic distension were unaffected by granisetron. In conclusion, 5-HT3 receptor antagonism blunts both the mechano- and chemoreceptor components of the human gastrocolonic response without altering antral compliance. In contrast, 5-HT3 pathways play no role in the ascending or descending components of the colonic peristaltic reflex. These findings demonstrate different roles for 5-HT3 receptors in the control of colonic motor function by the proximal gastrointestinal tract and by local neural reflexes.
结肠运动功能受涉及未知介质的广泛和局部神经反射调节。为了测试5-羟色胺（5-HT3）通路的作用，在健康人类志愿者中进行双盲格拉司琼（10微克/千克）或安慰剂输注后，测量胃窦扩张和十二指肠脂质灌注期间结肠张力的增加（胃结肠反应）以及局部结肠扩张（蠕动反射）时结肠近端和远端张力的变化。胃窦扩张引起结肠张力增加，格拉司琼使其减弱（P<0.05），而对胃窦顺应性无影响。十二指肠内脂质灌注也引起结肠张力增加，格拉司琼使其降低（P<0.05）。相反，结肠扩张期间结肠近端的收缩以及远端的舒张和收缩不受格拉司琼影响。总之，5-HT3受体拮抗作用减弱了人类胃结肠反应的机械感受器和化学感受器成分，而不改变胃窦顺应性。相反，5-HT3通路在结肠蠕动反射的升支或降支中不起作用。这些发现表明5-HT3受体在近端胃肠道和局部神经反射对结肠运动功能的控制中具有不同作用。
