粉防己碱抗氯化铯诱发家兔在体心脏早期后除极化及心律失常的作用

Effects of tetrandrine on early afterdepolarizations and arrhythmias induced by cesium chloride in rabbits

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-1·min-1共 10min ,对照组给予生理盐水 ,然后给予CsCl1 5mmol/kg静脉注射 ,给药前后记录心电图和右室心内膜单向动作电位 (MAP)。结果 Tet组和对照组均诱发早期后除极 (EAD) ,但Tet组EAD幅度小于对照组 ,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 。

Objective To determine the effects of tetrandrine on early afterdepolarizations (EAD) and arrhythmias induced by cesium chloride in rabbits Methods Fourteen rabbits were randomly divided into two groups tetrandrine group and control group,7 rabbits for each Tetrandrine was intravenously administered (0 5 mg·kg -1 ·min -1 ) in ten minutes for the tetrandrine group,while normal saline was given for the control group Then,Intravenous bolus doses of cesium chloride (1 5 mmol/kg) were given in two groups The lead II of electrocardiogram (ECG) and the endocardial monophasic action potential (MAP) of the right ventricle were recorded before and after the cesium chloride injection Results Cesium chloride induced EAD,decreased the MAP amplitude (MAPA),prolonged the monophasic action potential duration at 90% repolarization (MAPD 90 ) and R R interval in two groups But the EAD amplitude was less in tetrandrine group than in control group The incidence of ventricular arrhythmias was lower in tetrandrine group than in control group Conclusions Tetrandrine resisted the EAD induced by cesium chloride and inhibited ventricular arrhythmias That tetrandrine blocks Ca 2+ channel and slows the inward current could explain these observations