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

Summary 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.