Influence of neuregulin-1 on pacing threshold of low voltage area in rats after myocardial infarction / 心血管康复医学杂志

ABSTRACT

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.