Limb Ischemia Preconditioning Protects Against Lung Ischemia Reperfusion Injury In Rats

BACKGROUND:Studies find that limb ischemic preconditioning have obvious protective effects on ischemia reperfusion injury of remote vital organs.OBJECTIVE:To study the protective role of bilateral limb ischemia preconditioning during lung ischemia reperfusion injury in rats.METHODS:18male Sprague-Dawley rats of clean degree were randomly divided into three group:Sham group(group S,n=6),Ischemia/reperfusion group(group I/R,n=6),limb ischemia preconditioning group(group L,n=6).The Bilateral limb ischemia preconditioning(limb IP) was generated by3cycles of5min occlusion and5min release of the bilateral hind femoral artery. After limb IP,Lung I/R injury of rats was induced by blocking hilum of the left lung for one hour followed with reperfusion for two hour.At the end of experiments.the wet/dry ratio(W/D), activity of superoxide dismutase (SOD) and myleoperoxidase (MPO),the levels of malondialdehyde (MDA) were determined in lung tissues. The pathological changes of lung tissues were also observed.The contents of tumor necrosis factor-a(TNF-a), interleukin-1β(IL-1β) and interleukin-6(IL-6) in serum were detected using enzyme-linked immunosorbent assay.Results:Compared to the group I/R,the lung tissue W/D ratio,MPO activity,MDA and the cytokines(TNF-a, IL-1β and IL-6)levels significantly decreased in group L(P<0.05),while the SOD aetivity significantly increased(P<0.05).There were no statistical difference in the changes of the above parameters between group L and group S(P>0.05),The morphologic damages significantly reduced in group L.Conclusion:Limb ischemia preconditioning has protective effect against lung ischemia-reperfusion injury, which may be related to its inhibition of activation and infiltration of neutrophils and the release of reactive oxygen species and pro-inflammatory cytokines (TNF-α, IL-1β,IL-6).