Autophagy Is Involved in the Cardioprotection Effect of Remote Limb Ischemic Postconditioning on Myocardial Ischemia/Reperfusion Injury in Normal Mice, but Not Diabetic Mice

BackgroundRecent animal study and clinical trial data suggested that remote limb ischemic postconditioning (RIPostC) can invoke potent cardioprotection. However, during ischemia reperfusion injury (IR), the effect and mechanism of RIPostC on myocardium in subjects with or without diabetes mellitus (DM) are poorly understood. Autophagy plays a crucial role in alleviating myocardial IR injury. The aim of this study was to determine the effect of RIPostC on mice myocardial IR injury model with or without DM, and investigate the role of autophagy in this process.Methodology and ResultsStreptozocin (STZ) induced DM mice model and myocardial IR model were established. Using a noninvasive technique, RIPostC was induced in normal mice (ND) and DM mice by three cycles of ischemia (5 min) and reperfusion (5 min) in the left hindlimb. In ND group, RIPostC significantly reduced infarct size (32.6±3.0% in ND-RIPostC vs. 50.6±2.4% in ND-IR, ppConclusionsThe current study suggested that RIPostC exerts cardioprotection effect on IR in normal mice, but not DM mice, and this difference is via, at least in part, the up-regulation of autophagy.