Rouzade M L, Fioramonti J, Bueno L
Laboratoire de Pharmacologie-Toxicologie, INRA, Toulouse.
Gastroenterol Clin Biol. 1996;20(6-7):575-80.
The aim of this study was to determine, using specific antagonists, whether 5-HT3 receptors participate in triggering transient lower esophageal sphincter relaxations, independently or in relation with their CCKergic control.
Esophageal, lower esophageal sphincter and fundus pressure were manometrically monitored in 5 conscious dogs. Gastric distensions with air at constant pressure (1.0 and 1.7 kPa) were performed during 30 min under IV infusion of CCK8S (0.5 microgram/kg/h) or NaCl 9/1000 and were preceded (10 min) by IV administration of 5-HT3 receptors antagonists (ondansetron 0.2-500 micrograms/kg and granisetron 100 micrograms/kg) or NaCl 9/1000.
The number of transient relaxations induced by a 1.7 kPa gastric distension (7.9 +/- 0.4/30 min) was dose-dependently reduced by ondansetron (1-100 micrograms/kg) and by granisetron (100 micrograms/kg). Ondansetron (100 micrograms/kg) did not modify the number of relaxations under a 1.0 kPa gastric pressure (2.7 +/- 0.4 vs 2.6 +/- 0.4/30 min) but reduced the increase of the occurrence of relaxations induced by CCK8S under a gastric pressure of 1.0 and 1.7 kPa.
These results suggest that the CCK control in triggering transient lower esophageal sphincter relaxations is modulated by serotonin via 5-HT3 receptors subtypes.
本研究旨在使用特异性拮抗剂确定5-羟色胺3（5-HT3）受体是否独立地或与其胆囊收缩素能控制相关地参与引发食管下括约肌的短暂松弛。
对5只清醒犬进行食管、食管下括约肌和胃底压力的测压监测。在静脉输注胆囊收缩素八肽（CCK8S，0.5微克/千克/小时）或生理盐水（9/1000）的情况下，以恒定压力（1.0和1.7千帕）对胃进行30分钟的充气扩张，在这之前（10分钟）静脉注射5-HT3受体拮抗剂（昂丹司琼0.2 - 500微克/千克和格拉司琼100微克/千克）或生理盐水（9/1000）。
1.7千帕胃扩张诱导的短暂松弛次数（7.9±0.4/30分钟）被昂丹司琼（1 - 100微克/千克）和格拉司琼（100微克/千克）剂量依赖性地减少。昂丹司琼（100微克/千克）在1.0千帕胃压力下未改变松弛次数（2.7±0.4对2.6±0.4/30分钟），但减少了CCK8S在1.0和1.7千帕胃压力下诱导的松弛发生率的增加。
这些结果表明，血清素通过5-HT3受体亚型调节胆囊收缩素在引发食管下括约肌短暂松弛中的控制作用。
