氢溴酸槟榔碱对豚鼠体外胃不同部位肌条作用及其机制

Effect of arecoline on the different segments of isolated gastric smooth muscle strips from guinea pig in vitro

[目的]观察氢溴酸槟榔碱(Ah)对豚鼠体外胃不同部位平滑肌肌条收缩运动的影响,并初步探索其作用机制。[方法]用胃不同部位(6处)平滑肌条置于灌流浴槽,在37℃恒温、通氧和Krebs液灌注条件下,分别记录单独使用Ah和阻断剂孵育后Ah的收缩效应。[结果]①Ah可显著增高各部分体外胃平滑肌条的张力,增大收缩振幅和收缩波曲线下面积,2者均比基础值有显著增高(P<0.05)。而且其效应强度不同部位有明显差异。纵肌效应:Ah对胃窦纵肌的作用振幅大于胃底、胃体(P<0.01);效应曲线下面积大于胃体(P<0.01)。环肌效应:Ah对胃窦环肌作用振幅大于胃底(P<0.05);效应曲线下面积大于胃体和胃底(P<0.05),对胃体环肌作用的曲线下面积亦大于胃底(P<0.05)。②阿托品和维拉帕米均能部分阻断Ah的收缩作用,显著降低其振幅(P<0.01)。[结论]Ah对豚鼠体外胃平滑肌条的收缩活动有明显兴奋作用,推测这种效应部分介导于M-胆碱能受体,L型电压依赖性Ca2+通道。

[Objective] To observe the effect of arecoline（Ah） on the different segments of isolated gastric smooth muscle strips and explore the possible mechanism. [Methods] Gastric smooth muscle strips from uinea pig（six different parts）were suspended in issue chambers containing 4ml Krebs solution at 37℃ and its spontaneous contractive activity was observed and recorded. The response to arecoline and the effect of atropine and verapamil on arecoline induced contraction were also assessed. [Results] （1）Arecoline significantly raised the tension of all gastric muscle strips in Guinea pig and also increased contractile amplitude and areas under curves of all gastric mucle strips. To different parts, the effect was different. To longitudinal muscle strips（LMS. the contractile amplitude of gastric antral LMS was significantly larger than that of gastric fundus and gastric body （P〈0. 05）; the areas under curves of gastric antral LMS was significantly larger than that of gastric body （P〈0. 05）. To ring muscle strips（RMS）; the contractile amplitude of gastric antral RMS was obviously larger than that of gastric fundus （P〈0. 05）; the areas under curves of antral RMS was markedly larger than that of gastric body and the RMS of gastric fundus （P〈0. 05） ,and the areas under curves of RMS of gastric body was larger than that of gastric fundus （P〈0. 05）. （2） The effect of arecoline to gastric contraction could be eliminated by atropine and verapamil partially and the mean contractile amplitude increased （P〈0. 01）. [Conclusion] Arecoline has exciting stimulation on the contractile activity of isolated gastric muscle strips in Guinea pig and the periaqueductal gray stimulation of arecoline to stomach may be via muscarinic cholinergic receptor and L-type calcium channel.