神经调节蛋白-1干预对大鼠心肌梗死后低电压区起搏阈值的影响

摘要

Objective:To explore the influence of neuregulin- 1 (NRG-1)intervention on pacing threshold of low voltage area in rats after myocardial infarction.Methods:Myocardial infarction model of rat was established via an-terior descending coronary artery ligation.The 34 rats with myocardial infarction were randomly and averagely di-vided into two groups:NRG-1 group (received NRG-1peritoneal injection)and control group (received peritoneal injection of normal saline of the same volume).After two weeks,pacing thresholds were tested in low voltage area related with infarct in rats after myocardial infarction,and Cx43 (an integral membrane protein of the connexin family)expression was measured in low voltage area.Results:After drug intervention two weeks,compared with control group,there was significant reduction in pacing threshold [(1.466±0.503)V vs.(0.7167±0.194)V,P =0.002]in NRG-1 group;there was significant rise in Cx43 expression [(0.30±0.15)vs.(0.95±0.20),P <0.001] in low voltage area in NRG-1 group.Conclusion:Neuregulin-1 significantly reduces pacing threshold of low voltage area in rats after myocardial infarction,the mechanism may be related to increase Cx43 expression and improve e-lectrical conductivity of myocardial cells.%目的：探讨神经调节蛋白-1（NRG-1）干预对大鼠心肌梗死后低电压区起搏阈值的影响。方法：采用冠状动脉前降支结扎法建立心肌梗死大鼠模型，34只心肌梗死大鼠被随机均分为两组：NRG-1干预组（接受 NRG-1腹腔注射）和对照组（接受同体积生理盐水腹腔注射）。2周后测试大鼠心肌梗死后梗死相关的低电压区的起搏阈值，并检测低电压区 Cx43（连接蛋白家族的一种蛋白质）的表达。结果：药物干预2周时，NRG-1组起搏阈值明显低于对照组起搏阈值[（0.7167±0.194）V 比（1.466±0.503）V，P ＝0.002]；心肌梗死后低电压区 NRG-1组 Cx43表达较对照组明显增多[（0.95±0.20）比（0.30±0.15），P ＜0.001]。结论：NRG-1明显降低大鼠心肌梗死后低电压区起搏阈值，其机制可能与增加 Cx43表达，改善心肌细胞间电传导有关。