A Study Of Protective Effect Of Ischemic Postconditioning On Ischemia-Reperfusion Injury Of Lung

ObjectiveIschemia-reperfusion-induced lung injury may lead to primary graft failure and remain a significant cause of morbidity and mortality after lung transplantation. Ischemia-reperfusion lung injury is associated with cascade reaction of lipid peroxidation,leukocytic infiltration- activation,elastase releasing etc. Ischimic postconditioning is a new protective method of organ,which was found recently in the process of studying tissular protection of cardiac muscle,liver etc.With this method,we may relieve ischemia-reperfusion injury of lung and protect function of lung.Our experiment aims at studying protection of this method to lung of IRI and selecting the best way so as to obtain a new one relieving IRI of lung after operation and then provide experimental evidence to lung protection.MethodsRat orthotopic left pulmonary warm ischemia reperfusion model was established refering to Jiang Guanchao's method. Fifty rats were divided into five groups at random:·Group J(n=10): Dissociating hilum of left lung and not blockading it.Two hours and fifty later, samples were got.·Group IR(n=10): Dissociating hilum of left lung and blockading it for forty-five minutes,and then opening hilum of left lung .Two hours and five later, samples were got.·Group S1(n=10): First,dissociating hilum of left lung and blockading it for forty-five minutes.Second,manipulating pulmonary artery with ischemia-postconditioning after opening pulmonary vein and left bronchus.Two hours later, samples were got.·Group S2(n=10): First,dissociating hilum of left lung and blockading it for forty-five minutes.Second,manipulating pulmonary artery with ischemia-postconditioning after opening pulmonary vein and keeping left bronchus blockaded.Third,operning left bronchus. Two hours later, samples were got.·Group S3(n=10): First,dissociating hilum of left lung and blockading it for forty-five minutes.Second,manipulating pulmonary artery and left bronchus at the same time with ischemia-postconditioning after opening pulmonary vein.Two hours later, samples were got. and then all of samples were taken for H-E stain and detected in the laboratory.Results1. Pulmonary H-E stain of Group IR showed edema(both interstitial and alveolar space),neutrophil infiltration in alveolar tissue and damage of alveolus after 2 hours of reperfusion. Group S2 is similar to Group IR.Group S1 and S3 is better than Group IR.Group J is better than any others.2. SOD of Group J is higher than Group IR,and MDA/MPO/NE are lower than Group IR.3. SOD of Group S1 and S3 are higher than Group IR and lower than Group J; MDA/MPO/NE are lower than Group IR and higher than Group J.4. SOD/MDA/MPO/NE of Group S2 are similar to that of Group IR.Conclusion1. Ischemia-Reperfusion Injury of lung showed edema(both interstitial and alveolar space),neutrophil infiltration in alveolar tissue and damage of alveolus .2.Cascade reaction has happened after ischemic reperfusion,such as lipid peroxidation,leukocytic infiltration-activation and elastase releasing etc.3.The two ways of S1/S3 ischemic postconditioning can release IRI of lung,and they have no evident difference.4.The way of S2 can't release IRI of lung.