粉防己碱抗氯化铯诱发家兔在体心脏早后除极及心律失常的作用

目的 :研究粉防己碱 (Tet)抗氯化铯 (CsCl)诱发触发活动及触发性心律失常作用。方法 :14只家兔分对照组和Tet组 ,Tet组给予Tet 0 5mg kg min共 10min ,对照组给予生理盐水 ,然后给予CsCl1 5mmol kg静注 ,给药前后记录心电图和右室心内膜MAP。结果 :Tet组和对照组均诱发EAD ,但Tet组EAD幅度低于对照组 ,室性心律失常发生率低于对照组。结论 :Tet有抗CsCl诱发EAD及室性心律失常作用。其机制可能是Tet抑制慢钙通道 ,减少内向电流。

Effects of Tetrandrine on early after depolarizations and arrhythmias induced by Cesium Chloride in rabbits

Objectives:We studied the effects of tetrandrine on early afterdepolarizations(EAD)and arrhythmias induced by Cesium Chloride in rabbits.Method:14 rabbits were randomly divided into two groups|tetrandrine group and control group.Each group included 7 rabbits.Tetrandrine was intravenously given(0.5 mg/kg/min)in ten minutes in tetrandrine group,while normal saline was given in control group.Then,Intravenous bolus doses of Cesium Chloride(1.5 mmol/kg)were given to above two groups.We recorded the lead Ⅱ electrocardiogram (ECG)and the endocardial monophasic action potential(MAP)of the right ventricle before and after administration of Cesium Chloride.Result:Cesium Chloride was effective to induce the EAD,decrease the MAP amplitude(MAPA),prolong the monophasic action potential duration at 90% repolarization(MAPD 90) and R|R interval in two groups.But the EAD amplitude was lower in tetrandrine group than in control group.The rate of incidence of ventricular arrhythmias was lower in tetrandrine group than in control group.Conclusion:Tetrandrine is effective to resist the EAD induced by Cesium Chloride and inhibit ventricular arrlythmias.The mechanism may be Ca~ ++channel was blocked by tetrandrine and slows the inward current was slowed.