Platelet‐Derived Microparticles are Implicated in Remote Ischemia Conditioning in a Rat Model of Cerebral Infarction

AIM: Remote ischemic preconditioning protects against ischemic organ damage by giving short periods of subcritical ischemia to a remote organ. We tested the hypothesis that remote ischemic conditioning can attenuate cerebral stroke in a rat middle cerebral artery occlusion (MCAO) model by microparticles (MPs). METHODS AND RESULTS: MPs were extracted from healthy rats that underwent hindlimb ischemia-reperfusion preconditioning (RIPC), and were transfused into rats that had undergone MCAO without RIPC. The transfusion resulted in an increase in platelet-derived MPs in blood and reduction in infarction area, confirmed by both 2-3-5-triphenyltetrazolium chloride staining and magnetic resonance imaging, albeit to a lesser degree than RIPC itself. Behavioral tests (modified Neurological Severity Score [mNSS]) were calculated to judge the behavioral change. However, no significant difference was observed after MP transfusion in 24 h or the following consecutive 9 days. CONCLUSIONS: RIPC induces an increase in MPs, and platelet-derived MPs may confer at least part of the remote protective effect against cerebral ischemic-reperfusion injury.