Role Of The Jak/Stat Pathway In The Cardioprotection Of Remote Ischemic Preconditioning

Object iveTo investigate the effect of remote ischemic preconditioning on myoca rdial infarction、myocardium enzymes and cardiac muscle cell architecture inischemia-reperfusion injury of rats, and the involved protective mecha nisms.MethodsTwenty-four healthy male SD rats (200～250g) were randomly divided in to four groups, ischemia-reperfusion group (Group Ⅰ/R), ischemia30min and reperfusion120min without additional intervention; rote ischemic pr econditioning group (Group RIPC), take the noninvasive blood pressure mea surement instrument casing entangle the rat limb root, occlusion for5min, loosen5min, repeated4times; remote ischemic preconditioning+ischemia-reperfusion group (Group RIPC+I/R), the rats were comprised4cycles of5min reperfusion followed by5min ischemia, and then the rats were isch emia30min and reperfusion120min;AG490(JAK/STAT pathway inhibitor) group (Group AG490), rats were treated with remote ischemic preconditioni ng and ischemia-reperfusion,5min before reperfusion the rats were treat ed with AG490. After reperfusion120min,2ml blood were talen from the a-bdominal aorta, and then take the myocardial specimens. The blood sampl es were used to detect creatine kinase(CK)、lactic acid dehydrogenase(LDH) and troponin(cTNI). The myocardial infarct size was measured by TTC stain ing. The cell ultra micro-structure injury of myocardium was examined by electron and light microscope.ResultsMyocardial infarct size and myocardial enzyme were significantly redu ced in Group RIPC+I/R compared to those in Group I/R (P<0.05). Myocardial infarct size and myocardial enzyme were significantly increased in Group AG490compared to those in Group RIPC+I/R,but were significantly reduced in Group AG490compared to those in Group I/R(P<0.05).ConclusionRemote ischemic preconditioning provides cardioprotective effect.JAK/STAT pathway is involved in the cardioprotective effects of remote ische mic preconditioning.