Protective Effects of Pharmacological Preconditioning on Ischemic Reperfusion Injury

Objective:The purpose of this study is to explore the mechanisms underlying ischemia-reperfusion injury of the heart.To investigate the protective effects of pharmacological preconditioning(PPC) on ischemiareperfution injury.Methods: The heart of rabitts were used to made ischemia-reperfusion model in our experiment.All hearts were subject to 20 minutes local ischemia;then were reperfused for 30 minutes.Thirty rabitts were randomly divided into three groups:ⅠSham control group(SC);Ⅱ Adenosine preconditioning group(Adopc);Ⅲ Norepinephrine preconditioning(NEPC).Observed indexes include:①myocardial contractility.②the incidence of arrhythmia.③CK in blood.④myocardial ultrastructure observation.Results : The results showed that Ⅱ、Ⅲ group,Significantly improved myocardial contractility(±dp/dtmax) as compared with Ⅰ group during reperfusion period(P0.05),The incidence of reperfusion arrhythmia was higher in group Ⅱ and Ⅲ than in group Ⅰ(P0.01).CK leakage was remarkably reduced in group Ⅱand Ⅲ(P0.05).Myocardial electron microscope observation demonstrated that myocardial ultrastucture of group Ⅱand Ⅲ was better than of group Ⅰ.Conclusion : This study suggested pharmacological preconditioning can remarkably enhance cardio-protecive effects on ischemia-reperfusion injury.The cardio-protective effects of PPC were carried out by activating themselves endogenous protective mechanism.