Changes of cardiac function and myocardial apoptosis in rabbits after limb ischemia reperfusion

Objective To investigate the changes of cardiac function and myocardial apoptosis after limb ischemia reperfusion in rabbits.Methods Thirty rabbits were randomly divided into 3 groups:sham-operated control group (group SC),ischemia group (groupⅠ,8 hours of bilateral hind limb ischemia) and ischemia reperfusion group (group IR,4 hours of bilateral hind limb ischemia and 4 hours of reperfusion).Immunohistochemical studies and TUNEL were done to evaluate cell apoptosis.The SOD activity and MDA content in myocardial tissue and plasma LDH activity were determined. The left ventricular function were observed by physiology recording instrument.The cardiac histopathologic changes in experimental rabbits were observed.Results In group IR,the apoptosis index and expression of Bax were significantly increased compared with the other two groups.Similarly,ischemia reperfusion reduced SOD activity and enhanced LDH activity and MDA level,and the left ventricular function decreased in group IR.There was a positive correlation among the MDA content and the LDH activity,the expression of bax,the number of apoptosis cells.Under light microscope, myocardial impairment was found in group IR.Conclusion The myocardial injury occured and the left ventrieular function decreased after limb ischemia reperfusion,and they were associated with oxidative damage and apoptosis.