Influences of Shensong Yangxin capsule on expression of tyrosine hydroxylase mRNA and inducible ventricular arrhythmias after myocardial infarction in rabbits

Objective:To investigate the influences of Shensong Yangxin Capsule on the expression of tyrosine hydroxylase mRNA and susceptibility to ventricular arrhythmias in rabbit myocardial infarction models.Methods: Left anterior descending coronary artery was ligated to induce myocardial infarction in 30 rabbits,then they were randomly divided into SSYX group(treated with Shensong Yangxin Capsule,n=15) and MI group(n=15).Sham operation was performed in 15 control rabbits.After eight weeks,ventricular arrhythmias were induced by programmed electrical stimulation,and the expression of tyrosine hydroxylase mRNA was studied using real time fluorescent quantitation RT-PCR techniques.Results: ventricular arrhythmias incidence induced by programmed electrical stimulation was significantly higher in MI group than Sham group(46.7% vs.13.3%,P0.01).Shensong Yangxin Capsule treatment obviously decreased ventricular arrhythmias incidence compared with MI group(26.7% vs.46.7%,P0.05).The expression of tyrosine hydroxylase mRNA at infarction border and left ventricular wall in MI group were much higher than corresponding segments in sham group(P0.01).After eight-week Shensong Yangxin Capsule treatment,the expression of tyrosine hydroxylase mRNA was reduced remarkably campared with MI group(P0.05).Conclusion: In rabbit myocardial model,Shensong Yangxin Capsule treatment reduceds expression of tyrosine hydroxylase mRNA,and decresases incidence of ventricular arrhythmias.