The effects of atorvastatin on myocardial no-reflow after ischemia/reperfusion in rats

Objective To evaluate the effects of atorvastatin on myocardial no-reflow after ischemia/reperfusion in rats,and to investigate the possible mechanisms.Methods Fifty-six male SD rats were randomly assigned to four groups: shame group,ischemia and reperfusion group,atorvastatin group and atorvastatin+L-NNA group.Pretreatment of gastric lavage with atorvastatin [20 mg/(kg·d)] were given to subjects in atorvastatin group for 3 days.L-NNA(15 mg/kg) intravenous administration 15 minutes before ischemia plus atorvastatin pretreatment was given to subjects in atorvastatin+L-NNA group.All rats,except for those in shame group,received occlusion of left anterior descending artery(LAD) for 60 minutes followed by 120 minutes of reperfusion.Serum CK-MB and myocardial NO were detected after experiment.Different myocardium regions of ischemia,no-reflow and infarction were recognized and assessed according to Evans blue dye,thioflavin S fluorescent dye and triphenyltetrazolium chloride(TTC) staining techniques,respectively.Electronic microscope was applied to observe ultramicrostructures of capillary endothelial cells and myocardial mitochondria.Results Atorvastatin significantly elevated the myocardial NO,reduced CK-MB activity,relieved the microcirculation and myocardial mitochondrial injury,and reduced the no-reflow and necrosis areas(P0.05).However,these effects were reversed by L-NNA.Conclusion Atorvastatin can reduce the area of myocardial no-reflow after ischemia-reperfusion.This beneficial effect is dependant on NO by up-regulating eNOS expression,which activates mitochondrial K-ATP channel and reduces microvascular injury.