Effect of ischemia preconditioning on the expression of adhesion molecules in lung injury following ischemia-reperfusion of extremities in rats

Objective To investigate the effect of ischemia preconditioning(IPC) on the expression of ICAM-1 in lung injury after ischemia reperfusion of extremities(LIR) in rats.Methods 30 male healthy Wistar rats were randomly divided into three groups(10 each): Control group,ischemia-reperfusion group(IR) and ischemia preconditioning group(IPC).The positive rate of CD18 in blood polymorphonuclear neutrophil(PMN) was measured by using flow cytometry.The expression of intercellular adhesion molecule-1(ICAM-1) in lung tissues was detected by reverse-transcription polymerase chain reaction(RT-PCR) and Western blotting.The levels of wet/dry ratio(W/D) of lungs of different groups were determined.The biochemical method was used to measure the contents of myeloperoxidase(MPO) in lung tissues of different groups.The pathological changes in lungs were observed with light microscope.Results It was found that the levels of MPO and W/D were increased and the expression of ICAM-1 was up-regulated in lungs of IR group after rats' limbs suffering from ischemia-reperfusion(P0.01 or P0.05).However,ischemia preconditioning significantly decreased fluorescent positive rate of PMN CD18,attenuated the increase of MPO and W/D of lungs.The results of RT-PCR and Western blotting showed that the expression of ICAM-1 was down-regulated in lung tissue of IPC group than that of IR group.Pulmonary pathology revealed congestion and swelling in pulmonary microvessels with broadened pulmonary interstitial tissue and leucocyte infiltration dominated by neutrophils after limbs' IR.Conclusions Ischemia preconditioning may protect lung tissues from limb ischemia-reperfusion injury in rats,which is related to the down regulation of ICAM-1 expression.