氨乙基异硫脲对大鼠离体心脏冠脉结扎后再灌期心律失常与细胞动作电位的作用

Effects of AET on reperfusion induced arrhythmias and action potential alterations in the isolated rat heart with transient coronary artery occlusion

用Langendorff方法与微电极技术研究自由基清除剂氨乙基异硫脲(AET)对离体大鼠心脏冠脉结扎后再灌期心律失常与细胞动作电位的作用。AET(0.001～1mmol/L)使室颤和室速发生率明显下降,使正常窦性心律时间增加。浓度为0.01～1mmol/L的AET可使不可逆室颤发生率下降为零。冠脉阻塞再灌损伤使缺血中心区心肌动作电位波形异常,APA,RP,V_(max)各参数下降。AET(0.1mmol/L)可使异常波形动作电位显著减少。

We have used the isolated rat heart with 10 min coronary artery occlusion and 3 min reperfusion to investigate whether the free radical scavenger AET(2-β-aminoethyl-isothiourea)has the effect on the prevention of reperfusion arrhythmias.Inclusion of AET(0.001-1mmol/L)to the perfusate significantly reduced the incidence of reperfusion-induced ventricular fibrilation and ventricular tachycardia.Associated with this reduction in rhythm disturbances was an increase in the total duration of normal sinus rhythm during the 3 min of reperfusion.Electrophysiological studies indicated that APA,RP and Vmax were depressed due to the coronary occlusion and reperfusion injury.In the treatment of AET(0.1 mmol/L),the number of cells with abnormal AP was strikingly reduced.This confirms that AET treatment can protect myocardium from electrophysiological abnormalities,thus reducing the incidence of malignant arrhythmias.