大黄对豚鼠离体膀胱逼尿肌条收缩活动影响的实验研究

Effect of rhubarb on contractile activity of isolated bladder detrusor muscle strips in guinea pigs

目的:观察大黄水煎剂对豚鼠离体膀胱逼尿肌肌条的收缩活动并探讨其作用机理。方法:将逼尿肌肌条置于灌流肌槽内,采用累计加大黄和分别加阻断剂的方法,观察肌条的收缩活动。结果:M 胆碱能受体阻断剂阿托品及α1肾上腺素能受体阻断剂酚妥拉明可部分阻断其收缩反应,钙通道拮抗剂异搏定可阻断其振幅的增加。结论:大黄水煎剂增加收缩张力的作用可能部分通过兴奋M 胆碱能受体、α1肾上腺素能受体介导,其增大收缩波平均振幅的作用可能部分通过M 胆碱能受体以及L型电压依赖性钙通道介导。

Object: The purpose of this study was to assess the effect of the water extracts of rhubarb on bladder detrusor muscle and to examine the possible mechanism of its action. Methods: Bladder detrusor muscle strips from guinea pigs were suspended in organ baths and the isometric force were measured by ink-writing recorders. The response to rhubarb and the effect of hexamethonium, phentolamine, atropine and verapamil on rhubarb-induced contraction were also assessed. Results: (1) Administration of rhubarb dose-dependently increased resting tension, mean contractile amplitude and frequency in detrusor strips. (2) α-adrenergic receptor antagonist phentolamine, muscarinic cholinergic antagonist atropine and calcium channel blocker verapamil partly inhibited the contraction responses induced by rhubarb. Conclusion: The results suggest that rhubarb dose-dependently increased contractile tension, mean contractile amplitude and frequency of detrusor strips. The action of increased tension induced by rhubarb can be inhibited by atropine and phentolanine, suggesting that the action may be via M-muscarinic cholinergic receptor and α1-adrenergic receptor. The action of increased mean contractle amplitude induced by rhubarb can be inhibited by verapamil and atropine, suggesting that the action may be via L-type calcium channel and M-muscarinic cholinergic receptor.