Effect Of Distal Dexmedetomidine Intervention On Myocardial Ischemia-Reperfusion Injury In Rats

Objective:To explore the protective effect of intrathecal injection of dexmedetomidine on the myocardial ischemic reperfusion rats,and its mechanism.Methods:Forty-five Wistar adult male rats were randomly divided into 3 groups(n=15 each):sham operation group(Sham group),myocardial ischemia reperfusion group(I/R group)and Intrathecal dexmedetomidine pretreatment group(DEX group).The model of myocardial ischemia reperfusion injury was established by ligation of left anterior descending coronary artery(LAD)for 30 min and reperfusion for another 120 min.The LAD was only explosed,but not ligated in sham group.The rats in DEX group were injected intrathecally with dexmedetomidine of 1?g/kg for 30 min before operation.Equal volume of buffer solution was given in sham group and I/R group.The levels of Cardiac troponin I(cTnI)and norepinephrine(NE)were tested.Rats were sacrificed after blood collection,and myocardial infarct size was calculated and the expression of c-fos protein in spinal dorsal horn was detected.Results:Compared to sham group,the levels of cTnI,NE,myocardial infarction proportion and c-fos protein expression were significantly increased in I/R group and DEX group(p<0.05).Compared to I/R group,the level of cTnI,NE,myocardial infarction propotion and c-fos protein expression were significantly decreased in DEX group(p<0.05).Conclusion:Intrathecal dexmedetomidine,as central distal preconditioning,may have protective effects through inhibiting the expression of c-fos protein in spinal dorsal horn on the myocardial ischemic reperfusion rats.