银杏内酯对大鼠胃平滑肌电话动的作用

EFFECTS OF GINKGOLIDE A ON MYOELECTRIC ACTIVITY OF RAT STOMACH

目的 :探讨银杏叶提取物银杏内酯A对胃肌电活动的影响。方法 :离体灌注大鼠胃平滑肌标本 ,细胞外记录方法观察用药后平滑肌自发电活动的变化特点及其规律。结果 :银杏内酯A在 1μmol/L浓度时可显著压抑甚或消除外源性乙酰胆碱所介导的峰电位活动增强作用 (n =12 ,P <0 .0 1) ,但对平滑肌的正常慢波和自发峰电位活动无明显影响 ;在较高浓度 ( 5 0 μmol/L)时 ,银杏内酯A则使胃电慢波频率较对照增加 ,峰电位的活动加强 ,负载有峰电位的慢波频数显著增加 (n =7,P <0 .0 1) ,该效应不能被M胆碱能受体阻断剂阿托品所阻断。结论

Aim: To investigate the effects of ginkgolide A, which compounds extracted from the dried leaves of the ginkgo biloba tree, on gastric myoelectric activity of rat. Methods: Using extracellular recording method on the stomach smooth muscle in vitro. the changes of gastric myoelectric activity was observed during superfusion) of ginkgolide.Results: The infusion of ginkgolide A(1 μmol/L) prevlented potently the increase of acetylcholine(ACh)induced spike potential (SP) activity (n=12,(P<0.01), but it had no significant effect on normal gastric myoelectric activity. However, after administration of ginkgolide A at 50 μmol/L 35 minutes, the slow wave frequency and percentage of slow wave with SP were significantly increased (n=7,P<0.01). The effect cannot be inhibited by atropine, a cholinergic receptor blocker.Conclusion: Ginkgolide A had the modulation action on stomach smooth muscle movement and could cause the increase of gastric myoelectric activity at higher concentration.