Effect Of Nicorandil Preconditioning On MtDNA 4834bp Deletion Of Myochondial Ischemia-reperfusion Injury In Rats

Objecttive:To investigate the effect of nicorandil preconditioning on mitochondiral DNA4834 bp deletion of myochondial ischemia-reperfusion injury in rats.Methods:Weighing 200 g-300 g,aged between 7-9 weeks fifty healthy male Sprague-Dawley(SD) rats were randomly allocated into 5 groups(n=10 each):group Sham,group MIRI,group IPC,group Nic and group Nic+5-HD. MIRI grpup was induced by 30 min through occlusion of left circumflex coronary altery followed by 120 min reperfusion. In group Nic and Nic+5-HD a bolus of nicorandil 150 ug/kg was given iv at 10 min before myocardial ischemia followed by continuous infusion at 15 ug·kg-1min-1 until the beginning of myocardial ischemia.In group Nic+5-HD a bolus of 5-HD(mitochondrial ATP sensitive potassium channel blockers)10 mg/kg wag injected iv at 40 min before myocardial ischemia.The animals were sacrificed at the end of 120 min reperfusion.It is the modeling to establish rat myocardial ischemia reperfusion for separation of myocardial cell’s mitochondria and extract mitochondrial DNA.The mitochondrial DNA4834 bp deletion mutation was detected by nested-PCR(nested polymers chain reaction) technique.Results:The frequence of the mitochondrial DNA 4834 bp deletion mutation of MIRI group,IPC group,Nic group and Nic+5-HD group were 100%,20%,30%,89%.The mt DNA4834 bp mutation frequency of Nic group was significantly lower than MIRI group and Nic+5-HD group(P ﹤0.05),there were no significant difference between Nic group and IPC group(P﹥0.05).Conciusion:Nicorandil precondition decrease the mt DNA4834 bp deletion mutation of rats.