Study of sympathetic neural remodeling after myocardial infarction in rats
XI Yang *,QU Xiu-fen,YU Yan-wei,LI Jing-jie,ZHAO Gang,HUANG Yong-lin. * Department of Cardiology,First Hospital of Harbin Medical University,Harbin 150001,China
Objective To evaluate the sympathetic neural remodeling mechanism of ventricular arrhythmia after left ventricular myocardial infarction in rats and the effect of β-blocker on remodeling. Methods After treated with ligating the proximal portion of the left coronary artery or sham-operation procedure,the rats were classifed into 4 infarction groups and 4 control groups (3 days,7 days,30 days after surgery and propranolol taken orally). The density and extent of sympathetic innervation in left ventricular periinfarcted area、ventricular septum and right ventricle in different groups were examined by tyrosine hydroxylase immunohistochemistry. Results The density of sympathetic innervation were lower in periinfarcted area and ventricular septum,and higher in right ventricle in infarction groups compared with control group 3 days after surgery (P0.05). The density and extent of sympathetic innervation in periinfarcted area、ventricular septum and right ventricle were higher in infarction group compared with control group 7 days after surgery,that were more significant 30 days later (P0.01). Propranolol can decrease the density of sympathetic innervation in ventricular septum and right ventricle (P0.01),and normalize the extent of sympathetic innervation in the whole ventricle after left ventricular myocardial infarction. Conclusion These data indicate that left ventricular myocardial infarction resulted in sympathetic neural remodeling in periinfarcted area、ventricular septum and right ventricle,β-blocker can play an important role in improving this sympathetic neural remodeling.
【CateGory Index】： R542.22