连翘对豚鼠离体回肠运动的影响

目的:观察连翘对豚鼠离体肠管运动的影响,以期探讨其止呕作用的机制。方法:以呕吐相关受体激动剂为工具药,利用离体恒温浴槽,观察连翘对豚鼠离体回肠收缩的影响。结果:连翘能够抑制离体肠管的自发活动,表现为收缩张力降低,并呈剂量依赖性关系。乙酰胆碱(acetylcholine,Ach)、组织胺(histamine,His)、五羟色胺(5-hydroxytryptamine,5-HT)能够兴奋肠管,使张力升高、振幅变大,连翘高(10 g·L-1)、中(5 g·L-1)、低(2 g·L-1)剂量均能抑制以上3种工具药所致肠管收缩,降低其收缩张力和振幅,但对频率无明显影响。多巴胺(dopamine,DA)能够抑制肠管收缩,表现为张力降低、振幅变小,连翘高剂量和中剂量能够拮抗DA的肠管松弛作用,使张力升高、振幅变大;连翘低剂量能够进一步使张力降低,但使振幅增大。结论:连翘可以抑制豚鼠回肠运动,其机制可能是通过阻断肠平滑肌上的M受体、H1受体、5-HT受体和D2受体,也可能是对肠管的直接抑制作用,其止呕机制尚待进一步深入研究。

Effects of Forsythiae Fructus on guinea pig ileum contractility in vitro

Objective: To study contractility of guinea pig ileum in vitro,and analyze the mechanism of anti-emetic effects of Lianqiao. Method: Using emesis-relating agonists as drugs, the inhibitory effects of Lianqiao on guinea pig ileum contractility in vitro were observed in organ bath. Result: Lianqiao could inhibit guinea pig ileum spontaneous contractions,reducing the tone of contractions dose-dependently. Acetylcholine(Ach), histamine(His), 5-hydroxytryptamine(5-HT) stimulated contractions of the guinea pig ileum,enhanced the tone and amplitude. All the three doses (10,5,2 g·L^-1) of Lianqiao could suppress the contractility,significantly reduced the tone and amplitude of ileum contractions stimulated by drugs but not the frequency. Dopamine could inhibit the spontaneous contraction tone and amplitude of ileum; Both the large doses(10, 5 g·L^-1) of Lianqiao could antagonise the inhibitory effect of DA,enhance the tone and amplitude. Small dose(2 g·L^-1) had additive effects on tone of ileum contractions with DA,but enhanced the amplitude not the frequency. Conclusion: Lianqiao have an inhibitory effect on guinea pig ileum contractions,the mechanism might be blocking M receptor, H₁ receptor,5-HT receptor and D₂ receptor or directly suppressed ileum smooth muscle. The mechanisms of anti-emetic effect of Lianqiao needs further study.