硫酸锌预处理对大鼠缺血再灌注心肌Cx43及再灌注室性心律失常影响

Effect of ZnSO_4 Precondition on Myocardium Celluar Cx43 Protein during Ischemia / Reperfusion and Reperfusion Ventricular Arrhythmias in Rats

目的观察硫酸锌预处理对大鼠心肌缺血再灌注(I/R)引起的室性心律失常的影响,探索硫酸锌对缝隙连接蛋白43(Cx43)的调节。方法雄性SD大鼠随机分为假手术+生理盐水预处理组(Sham+Sa组),假手术+硫酸锌预处理组(Sham+Zn组),I/R+生理盐水预处理组(I/R+Sa组),I/R+硫酸锌预处理组(I/R+Zn组),每组6只。建立大鼠心肌缺血再灌注模型,观察再灌注60 min内室性心律失常发生的情况,采用蛋白印迹(Western-Blot)技术检测各组Cx43磷酸化水平。结果与Sham+Sa组及Sham+Zn组相比,I/R+Sa组心律失常评分显著升高(P<0.01),心室肌Cx43去磷酸化水平显著升高(P<0.01)。与I/R+Sa组相比,I/R+Zn组心律失常评分显著减低(P<0.01),心室肌Cx43去磷酸化水平降低(P<0.01)。结论硫酸锌预处理可以显著降低大鼠缺血再灌注室性心律失常的发生,其机制可能与硫酸锌调控缺血再灌注后Cx43磷酸化水平有关。

Objective To investigate the arrhythmia and the phosphorylation of gap junction protein Connexin43 （Cx43 ） during the ischemia/reperfusion injury in rat heart and effects of ZnSO4 （zinc）precondition on it.Methods The male SD rats were randomly divided into 4 groups：sham with saline precondition group（Sham＋Sa）,sham with ZnSO4 precondition group（Sham＋Zn）,ischemia/reperfusion with saline precondition group（I/R＋Sa）,ischemia/reperfusion with ZnSO4 pre-condition group（I/R＋Zn）（n=6 in each）.The incidence of ventricular arrhythmias and arrhythmia score were observed and the phosphorylation level of Cx43 was evaluated by Western-Blot in each group.Results Compared with the Sham＋Sa group and Sham＋Zn group,ventricular arrhythmia score in I/R＋sa group was obviously increased （P〈0.01 ）,and the phosphorylation level of Cx43 in ventricular myocardial cells was also significantly increased （P〈0.01 ）.Compared with the I/R＋Sa group,ventricular arrhythmia score in I/R＋Zn group obviously decreased （P〈0.01 ）,and the phosphoryla-tion level of Cx43 in ventricular myocardial cells was also significantly decreased （P〈0.01）.Conclusion ZnSO4 precon-dition can effectively reduce the incidence of reperfusion ventricular arrhythmias which may be associated with the modula-tion of Cx43 phosphorylation during ischemia/reperfusion in rats.