Platelet-derived microvesicles are involved in cardio-protective effects of remote preconditioning.

The ischemia-protective mechanism of remote precondition has been a mystery for a long time. Little was known about details of the inter-organ cardio-protective. Microvesicles, also known as microparticles (MPs), are small membrane-vesicles budding from the plasma membrane of cell. Recent studies have indicated MPs to be an important messenger in various biological processes. Our research mainly examined the hypothesis that remote ischemic conditioning can attenuate heart infarction in a rat after they were subjected to 30 min ischemia and 180 min reperfusion (I/R) by MPs. MPs were extracted from three groups of rat: 1) healthy rats, 2) healthy rats that underwent hindlimb ischemia-reperfusion preconditioning (RIPC) immediately, 3) healthy rats that underwent RIPC in 6 hours. Isolated MPs were transfused into rats that had undergone I/R without RIPC. The transfusion of MPs from rats that underwent RIPC immediately resulted in an increase in platelet-derived MPs in blood and reduction in infarction size, confirmed by 2-3-5-triphenyltetrazolium chloride staining. We further observed the contractile function in hearts after they were subjected to different treatments. However, no significant difference was observed in transfusion of MPs from rats that underwent RIPC in 6 hours. RIPC induces an increase in MPs, and platelet-derived MPs may confer at least part of the remote protective effect against cardiac ischemic-reperfusion injury.