兔肺动脉栓塞再灌注中内皮素1、一氧化氮、血管假血友病因子、热休克蛋白的变化

目的 探讨兔肺动脉栓塞缺血再灌注模型中肺损伤发生的可能机制.方法 健康新西兰白兔30只,雌雄不拘.运用5F Berman球囊堵塞左下肺动脉,然后球囊放气,复制肺动脉栓塞缺血再灌注模型.随机分为5组:假手术组、肺动脉栓塞1 h组、肺动脉栓塞2 h组、肺动脉栓寒2 h再灌注1 h组和肺动脉栓塞2 h再灌注2 h组.各组动物分别在实验结束放血处死,即刻抽取静脉血,分别采用放射免疫法测定血浆内皮素1(ET-1)的含量,硝酸还原酶显色法测定一氧化氮(NO)的含量,酶联免疫法测定血管假血友病因子(vWF)的含量.实验结束取肺组织分别用4%多聚甲醛及4%戊二醛固定,采用免疫组织化学方法测定热休克蛋白70(HSP70)的表达,并进行组织病理分析观察组织超微结构变化.结果 与假手术组相比,肺栓塞1 h、2 h血浆中ET-1、NO、vWF的含量明显增多;再灌注后进一步增高,再灌注2 h升高最为明显.血浆中NO/ET-1在肺栓塞1 h,肺栓塞2 h、再灌注1 h、再灌注2 h明显降低.兔肺动脉栓塞时肺组织细胞HSP70的表达明显增加,再灌注后1 h、2 h蛋白表达继续增加,并随着再灌注时间延长而增加(P＜0.01).肺栓塞再灌注后透射电镜显示超微结构毛细血管内皮细胞肿胀、空泡化、部分胞浆溶解,核染色质浓缩,线粒体部分或大部分嵴和膜融合消失.结论 肺动脉柃塞再灌注过程中血浆的ET-1、NO、vWF含量增加及肺组织超微结构变化提示,内皮细胞损伤及功能障碍可能参与肺缺血再灌注损伤.HSP70在肺栓塞缺血再灌注过程中表达增加,推测HSP70参与了肺缺血再灌注损伤的保护.

Change of endothelin-1, nitric oxide-yon Willebrand factor and heat shock protein 70 in lung ischemia reperfused rabbit

Objective To investigate the possible mechanism of ischemia-reperfusion lung injury and the role of heat shock protein 70 (HSP-70) in the lung ischemia-reperfusion process.Methods Thirty healthy New Zealand rabbits were studied,of which the left lower lung artery was obstructed by inflating gas of 5F Berman sacculus catheter to set up rabbit pulmonary embolism model,then the gas of sacculus was put out to result in blood reperfusion.The animals were randomly divided into five groups:sham group,embolism 1 h group,embolism 2 h group,embolism 2 h and reperfusion 1 h group,embolism 2 h and reperfusion 2 h group.The venous blood samples of all rabbits were drawn before putting to death.The plasma content of endothelin-1 (ET-1),NO and yon Willebrand factor(vWF) were respectively detected by radio-immunoassay method,nitrate reductase method and enzyme-linked immunosorbent assay.At the corresponding time,the left lung tissue specimen was fixed by 4% polyformaldehyde and 4% glutaraldehyde respectively,the expression of HSP70 was determined by immunohistochemistry,and the uhrastructural change of the lung tissue was observed by histopathologic analysis.Results Compared with those of sham group,the plasma contents of ET-1,NO,vWF significantly increased 1 h,2 h after lung embolism,further increased after reperfusion,and the increase was the most obvious at reperfusion 2 h.NO/ET-1 ratio in embolism 1 h,2 h and reperfusion 1 h,2 h was obviously lower than that of sham group.Compared with that of sham group,the positive expression of HSP70 in rabbit lung tissue was remarkably increased at embolism 1 h,2 h,and reperfusion 1 h,2 h(P＜0.01).HSP70 expression in reperfusion 1 h,2 h groups was higher than that in embolism 1 h,2 h groups(P＜0.01).Transmission electron microscope showed cell swelling,vacuolization,partial plasmolysis,and dense nuclear chromatin in capillary endothelium after lung reperfusion.Conclusions The result of ET-1,NO,vWF in plasma and ultrastructure change in lung show that endothelial cell injury and functional disturbance participate in the lung eischemia-reperfusion injury.HSP70 overexpresses in the process of the lung ischemia-reperfusion.It is presumed that HSP70 participates in the protection of the lung injury.