Influence of Resistance Training on Myocardial Neuregulin-1 Expression and Cardiac Structure and Function in Rats with Myocardial Infarction

Objectives:To discuss the influence of resistance training on cardiac structure and function, expression of Neuregulin-1 (NRG1) and its signaling pathway in rats with myocardial infarction (MI) .Methods:Adult male sprague-dawley rats, 3-mouth old, weight about 180-220 g were randomly divided into three groups:Sham-operated group (Sham) , sedentary MI group (MI) and MI with resistance training group (MR) .The MI model in rat was established by ligation of the left anterior descending (LAD) coronary artery, and rats in MR were subjected to 4-week resistance training.At the end of the 4-week training, hemodynamic measurement was preformed to evaluate cardiac function;after that the heart was picked for histological section.The expression levels ofα-SMA, CD105, BCL-2, Bax, NRG1, ErbB2, ErbB4, PI3 K, Akt and ERK1/2were detected by Immunohistochemical measurement, Western Blotting or RT-qPCR.Results:Compared with MI group, resistance training has effectively promoted cardiac function and the pathological myocardial hypertrophy, increased BCL-2/Bax ratio and the expression ofα-SMA, CD105, NRG1 protein and erbb2, erbb4 mRNA in myocardial tissue, upregulated the phosphorylation levels of PI3K-Akt and ERK1/2 signal.Conclusion:Resistance training could improve the cardiac function by ameliorating cardiomyocyte pathologic hypertrophy, inhibiting apoptosis and promoting angiogenesis after MI, its mechanism may be associated with NRG1 and the activation of its downstream signaling pathways.