Effects of ischemic postconditioning on ischemia-reperfusion arrhythmias in rats

Objective To observe the effects of postconditioning on ischemia-reperfusion arrhythmias in rats,and to explore its possible mechanism. Methods Twenty-four male Wistar rats were randomly divided into 3 groups:sham operation group(n=8),ischemia-reperfusion group(n=8),ischemic postconditioning group(n=8).The myocardial ischemia-reperfusion model was established by ligation of the left anterior descending coronary artery for 30 min,followed by 120 min reperfusion.ECG was monitored during the entire process.The expression of Cx43 mRNA was measured by reverse transcription-PCR,and ventricular arrhythmias was detected with ventricular arrhythmia score(VAS). Results Compared with sham operation group,Cx43 mRNA expression level was signi- ficantly lower in ischemia-reperfusion group(P0.01).Compared with ischemia-reperfusion group,Cx43 mRNA expression significantly increased in ischemic postconditioning group(P0.01).Compared with sham operation group,ventricular arrhythmias score significantly increased in ischemia-reperfusion group(P0.01).Compared with ischemia-reperfusion group,ventricular arrhythmias score decreased significantly in ischemic postconditioning group(P0.01). Conclusion Postconditioning could reduce the occurrence of reperfusion arrhythmias by inhibiting degradation of Cx43 mRNA caused by ischemia-reperfusion in ventricular myocytes.