Abstract: Objective to investigate the alleviative effects of lidocaine postconditioning on pulmonary injury following ischemia reperfusion. Methods 72 adult SD rats were randomized to 4 groups (n=18 for the each): sham group, ischemia-reperfusion group, ischemic postconditioning group and lidocaine postconditioning group. The pulmonary ischemia-reperfusion model was established by occlusion of the left hilum of lung for 45min and the reperfusion was taken by removing the clamp for 2h. At the moment of reperfusion, lidocaine 4mg/kg was injected in as a priming dose following a continuous rate of 4mg/kg·h. PaO2, TNF-α, W/D of left lung, the level of MDA of left lung tissue were measured. At the end of reperfusion left lung was removed for microscopic determination. Results Following reperfusion PaO2 of lidocaine group was much higher than that of I-R group（P＜0.05）. Lidocaine postconditioning induced a significant decrease in the level of MDA of lung tissue（7.03±1.17μmol/L） compared with ischemia reperfusion group ( 8.77±1.42μmol/L）（P＜0.05）.Lidocaine postconditioning resulted in a lower level of TNF-α（1.69±0.34μg/L）than that of I-R group(2.52±0.54μg/L）（P＜0.05）. Microscopic examination showed that lidocaine postconditioning could decrease the level of edema of left lung and accumulation of neutrophils. Conclusion Lidocaine postconditioning exerts a protective effect on pulmonary ischemia-reperfusion injury administered in the beginning of reperfusion. The effect may be related to the antioxidant effect and the suppression of expression of TNF-α.

Key words: ischemia reperfusion, lidocaine, postconditioning, pulmonary