缺血预处理对离体大鼠肺缺血再灌注氧化损伤的影响

目的 :研究缺血预处理 (IP)对离体大鼠肺缺血再灌注氧化损伤的影响。方法 :建立离体大鼠肺缺血再灌注损伤模型。 18只SD大鼠随机分为 3组 ,每组 6只。对照组 (Con)持续平衡灌注通气 60min ,无缺血 ;缺血再灌注组 (IR)缺血 45min ,再灌注 3 0min ;缺血预处理组 (IP)先给予连续 2次的 5min缺血、5min再灌注的预处理 ,再行缺血 45min和再灌注 3 0min。测定缺血前和再灌注末灌注液中丙二醛 (MDA)、超氧化物歧化酶 (SOD)和白细胞数量 ,测定再灌注末肺组织髓过氧化物酶 (MPO)活性、黄嘌呤氧化酶 (XOD)活性和湿 /干比 (W /D)。结果 :IR组再灌末MDA含量、MPO活性、XOD活性和W /D较Con组明显升高 (P <0 0 1) ,而SOD活性则显著下降 (P <0 0 1)。IP能明显减少再灌后MDA、MPO、XOD和W /D的增加 ,提高SOD的活性 (P <0 0 1)。结论 :IP能明显抑制离体大鼠肺缺血再灌注导致的氧化损伤。

THE EFFECTS OF ISCHEMIC PRECONDITIONING ON OXIDATIVE INJURY INDUCED BY ISCHEMIA-REPERFUSION IN ISOLATED RAT LUNGS

Objective:To investigate the effects of ischemic preconditioning on oxidative injury induced by ischemia-reperfusion in isolated rat lungs.Methods:A model of ischemia-reperfusion injury in buffer-prefused rat lungs was used.Eighteen rats were randomly allocated into three groups,6 in each group.Control group (Con) was perfused and ventilated for 60 min without ischemia,ischemia-reperfusion group (IR) was interrupted with perfusion and ventilation for 45 min followed by reperfusion for 30 min,ischemia-preconditioning group (IP) was applied ischemic preconditioning (5 min ischemia and 5 min reperfusion for two times) before 45 min warm ischemia and 30 min reperfusion.The level of Malondialdehyde (MDA),superoxide dismutase (SOD) and white blood cell (WBC) were measured before ischemia and at the end of reperfusion in perfusate,the myleoperoxidase (MPO) activity,xanthine oxidase (XOD) activity and wet to dry weight ratio (W/D) of lungs were also measured at the end of the experiment.Results:After 45 min ischemia and 30 min reperfusion,the levels of MDA,XOD activity,MPO activity and W/D were significantly higher in IR group than those in Con group,but the activity of SOD was significantly decreased (P<0.01).IP significantly attenuated the increase of MDA,MPO,XOD and W/D after I/R,but increased the activity of SOD.Conclusions:The data showed that ischemic precontioning could attenuate the oxidative injury induced by ischemia-reperfusion in isolated rat lungs.