Effects Of Lipoxin A4 On Lung Ischemia-reperfusion Injury In Rats And Its Mechanism

Objective: To study effect and mechanism of lipoxinA4(LXA4)on lung ischemia/reperfusion injury in rats,so as to provide the basis of clinical application.Method: 36 healthy male Sprague-Dawley rats of SPF degree,weighting 230~280g,were randomly divided into three groups(n=12): Sham operation group(S Group),Ischemia/reperfusion group(IR Group): blocking the left hilar after 45 min and then restore the blood reperfusion,Lipoxin A4 group(LX Group): 0.1 mg/kg of lipoxinA4 was administered 10 min before reperfusion,and the rest of the treatment was performed with the IR group.At the end of experiments,activity of superoxide dismutase(SOD)and myleoperoxidase(MPO),the levels of malondialdehyde(MDA)were determined in lung tissues;The contents of interleukin-1?(IL-1?),interleukin-6(L-6)and tumor necrosis factor-?(TNF-?)in lung tissues were detected using enzyme-linked immunosorbent assay(ELISA)and the expression of HO-1 were detected using western blot;the wet/dry ratio(W/D);The pathological changes of lung tissues were observed through HE staining by optocal microscope.Results: Compared to the Group IR,W/D ratio,MPO activity,MDA and cytokines(IL-1?,TNF-?)levels in the lung tissue of Group LX significantly decreased(P<0.05),the lung tissue SOD activity and HO-1 significantly incresaed(P<0.05).the morphologic damages significantly reduced in Group LX.Conclusion: Lipoxin A4 administration has protective effect against LIRI,which may be related to its inhibition of activation and infiltration of neutrophils and the release of reactive oxygen species,pro-inflammatory cytokines(IL-1?,TNF-?)and upregulation of HO-1,and these may finally help to peotect lung from injury.