银杏叶提取物对结肠运动的影响机制

The effect of ginkgo biloba extract on colonic motility in guinea pig

目的 探讨银杏叶提取物 (EGb)对豚鼠离体结肠运动的影响及其机制。方法 制备豚鼠离体结肠肠段标本 ,通过灌流给药的方法观察不同浓度EGb、银杏黄酮等对离体结肠收缩活动的影响。结果 EGb (0 5～ 5 0 0mg/L)可对结肠自主活动产生抑制和兴奋两种不同的影响 ,其中以抑制作用为主。EGb也可部分拮抗由ACh、5 HT引起的结肠运动的增强效应 ;并协同血管活性肠肽 (VIP)、无钙Kreb液灌流引起的抑制作用 ;对γ 氨基丁酸、肾上腺素引起的结肠运动抑制效应无显著影响 ;用M受体阻断剂阿托品预处理可部分阻断EGb对结肠自主活动的影响。银杏黄酮 (0 0 1～ 0 1mg/L)可使豚鼠离体结肠运动抑制 ,且表现一定的剂量依赖性。结论 EGb对豚鼠结肠运动的影响可能是通过影响 5 HT、ACh、VIP等肠神经系统递质的释放 ,经M受体介导以及对平滑肌的直接作用等多种途径实现的。银杏黄酮可能是EGb发挥抑制作用的有效部位。

Objective To explore the effect of ginkgo biloba extract(EGb) on colonic motility of guinea pig and the mechanism in vitro . Methods The role of colonic motility at different dosages of EGb and Flavonoids was separately observed. Results EGb induced two kinds of actions: inhibition and excitation. EGb could antagonize the effect stimulated by ACh and 5-HT. And it could increase the inhibitory effect of VIP and perfusion by free Ca 2+ Krebs solution. But EGb had no effect on norepinephrine,GABA and atropin. Flavonoids could inhibit significantly the spontaneous contraction of colon dose-dependently. Conclusion EGb may regulate the motility of colon of Guinea pig through 5-HT,ACh,VIP,Ca 2+ ,M-receptor and direct effect on the intestinal muscle. Flavonoids,which has restraining effect on isolated colonic motility,may be one of valid elements of EGb which inhibits colonic contraction.