应激诱导磷蛋白1可能通过调节Cx43表达影响低温缺血再灌注后心室肌电传导

STIP1 may affect ventricular myoelectric conduction after hypothermic ischemia-reperfusion by regulating the expression of Cx43

目的探讨低温缺血再灌注心律失常大鼠心室肌电传导变化及其可能机制。方法选择清洁级2~3月龄健康雄性SD大鼠,制备离体心脏灌注模型16个,随机分为两组(n=8),正常对照组(C组):持续灌注37℃K-H液120 min;低温缺血再灌注组(IR组):持续灌注37℃K-H液30 min后停止灌注60 min,随后再灌注30 min。分别在持续灌注15 min(T_(0))、持续灌注30 min(T_(1))、再灌注15 min(T_(2))、再灌注30 min(T_(3))时点采集心率(HR)、传导速度(CV)和电传导图并记录心律失常情况;通过Western blot和免疫组化检测再灌注后左心室前壁组织应急诱导磷蛋白1(STIP1)、连接蛋白43(Cx43)蛋白的表达和分布。结果IR组:在再灌注期间,有7例发生心律失常;在T_(2)、T_(3)时点与T_(0)和T_(1)比较,HR、CV明显降低(P<0.05)且传导方向呈发散改变。与C组比较,IR组心肌组织中STIP1、Cx43蛋白表达均明显降低(P<0.05),IR组Cx43蛋白着色的颗粒减少,有偏侧化现象。结论STIP1可能通过调节Cx43表达影响低温缺血再灌注后心室肌电传导。

Objective To investigate the changes of ventricular myoelectric conduction and its possible mechanism in hypothermic ischemia-reperfusion arrhythmia rats.Methods Healthy male SD rats aged 2~3 months were selected to prepare isolated heart perfusion models(n=16).The rat models were randomly divided into normal control group(C group,continuous perfusion of 37℃K-H solution for 120 min)and hypothermic ischemia-reperfusion group(IR group,continuous perfusion of 37℃K-H solution for 30 min,reperfusion stopped for 60 min,and then reperfusion for 30 min),with 8 rats in each group.Heart rate(HR),conduction velocity(CV)and electrical conduction chart at the timepoint of continuous perfusion for 15 min(T_(0)),continuous perfusion for 30 min(T_(1)),reperfusion for 15 min(T_(2))and reperfusion for 30 min(T_(3))were collected,and the arrhythmia was recorded.The expression and distribution of STIP1 and Cx43 in the anterior wall of left ventricle after reperfusion were detected by western blot and immunohistochemistry.Results IR group had 7 cases of arrhythmia during reperfusion.Anlayis on IR group showed,HR and CV were decreased significantly at T_(2)and T_(3)when compared with T_(0)and T_(1)(all P<0.05)and the conduction direction showed divergent change.The expression of STIP1 and Cx43 protein in myocardial tissue of IR group were apparently decreased when compared with C group(both P<0.05),and Cx43 positive stained particle numbers in IR group were also decreased,in which the phenomenon of lateralization was observed.Conclusions STIP1 may affect ventricular myoelectric conduction after hypothermic ischemia-reperfusion by regulating the expression of Cx43.