The effect of TNF-α early expression on ventricular arrhythmias in rats with AMI and the study for mechanism

Objective:To investigate the effect of TNF-α early expression on ventricular arrhythmias in rats with AMI and the mechanism.Methods:Rats with AMI were induced by left anterior descending coronary branch ligation.The mRNA and proteinum expression level of TNF-α were detected by real-time fluorescent quantitative PCR and histochemistry.Electrocardiogram was also recorded.Different concentrations of TNF-α were added to isolated rat hearts to observe the arrhythmia effects.The effect of TNF-α on intracellular Ca2+ concentration was detected by laser confocal technique.Results:The mRNA and protein expression levels of TNF-α were higher in MI group than in S group from 10 min after AMI(P0.05).The frequency of ventricular arrhythmias was higher in MI group than in S group(P0.05)and the occurrence time of ventricular arrhythmias was coincided with the secretion of TNF-α.200 U/ml TNF-α could cause ventricular arrhythmias.Using etanercept beforehand,arrhythmias by TNF-α were reduced(P0.05).TNF-α increased intracellular Ca2+ intensity.Conclusion:There is relationship between TNF-α early expression and ventricular arrhythmias in rats with AMI.The effect might be associated with the increased intracellular Ca2+ intensity caused by TNF-α.