Experimental study on the dose-response relation of myocardial protection:hyperpolarized cardioplegic arrest with nicorandil / 医学研究生学报

ABSTRACT

Objectives:Dose-response effect of nicorandil cardioplegia at various concentrations was studied to optimize its myocardial protective effect.Methods:Forty-eight isolated working rat hearts were divided into 6 groups randomly.They were group A:control (depolarized cardiac arrest with St.Thomas solution No.2),group B,C,E,F and G:hyperpolarized cardiac arrest (nicorandil concentration were 25,50,100,125 and 150μmol/L respectively).The hearts underwent a 120-minute hypothermic arrest (15±1)℃ with cardioplegia (40 ml/kg) and reinfused with cardioplegia (40 ml/kg) at interval of 30 minutes.Mechanical arrest time,cardiac functional recoveries,myocardial content of malondialdehyde (MDA) and ultrastructure were measured.Results:The protective effect of nicorandil cardioplegia was dose-related.Conclusions:The optimal concentration of nicorandil in cardiplegia may be 100μmol/L for myocardial protection.