Effect of JAK-STAT pathway on myocardial ischemic post-conditioning in rabbit hearts

Objective To explore the effect of JAK-STAT pathway on myocardial ischemic postconditioning(IPO)in vivo model of rabbit heart.Methods Thirty rabbits were randomly divided into three groups.Group 1(ischemic/reperfusion,I/R,n =10):the left anterior descending(LAD)of each rabbit heart was reperfused for 120 min after being occluded for 30 min.Group 2(ischemic postconditioning,IPO,n =10):before the 120 min reperfusion,the LAD was loosen and cut off every 30 s,for 3times.Group 3(AG490+IPO,n =10):like group 2,the difference was given tyrosine inhibitor AG490.Taken the time before occlusion 10 min as starting point,every 10 min,we recorded left ventricle pressure in the procedure of ischemic reperfusion.Through collecting 2ml blood as a sample at the specified time,creatine phosphatekinase(CPK)was detected.After the experiment was completed,all hearts were detected for the apoptosis on the myocardium.Results The level of CPK in group 2was significantly decreased compared to group 1(P 0.05).There were no significant difference between group 1and group 3.It has a bad heart function if±dp/dt max approach to zero.The heart function in group 1was downtrend compared with group 2.In group 3,the heart function was downtrend,too.The cadiocyte apoptosis of group 1and group 3was higher than that of group 2.The statistical results showed that the contrast between group 1and group 2was significant(P 0.05);there were no significant difference between group 1and group 3.Conclusion IPO can reduce the release of CPK,necrosis and apoptosis of cell;improve the heart function.The JAK-STAT pathway participates the protection mechanism of IPO.