兔肺动脉栓塞/再灌注损伤中肺泡细胞凋亡及其Fas/FasL表达的变化

目的:观察兔肺动脉栓塞/再灌注损伤中肺泡细胞凋亡及其Fas及FasL蛋白表达的变化,探讨肺损伤的可能机制.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(n=6):假手术组,肺动脉栓塞1 h组、肺动脉栓塞2 h组,肺动脉栓塞2 h再灌注1 h组、肺动脉栓塞2 h再灌注2 h组;另设6只正常未手术白兔为对照组.实验结束取肺组织,测定肺组织湿/干重比,采用流式细胞分析法检测肺组织细胞凋亡率,免疫组织化学法检测肺上皮细胞Fas及FasL蛋白表达的变化.结果:与对照组、假手术组相比,肺动脉栓塞1、2 h组兔肺组织细胞凋亡率明显增加,再灌注后凋亡细胞进一步增多,并随着再灌注时间延长而逐渐增多(P＜0.05或0.01);Fas及FasL蛋白表达在肺动脉栓塞及再灌注后明显上调(P均＜0.01).肺泡上皮细胞凋亡指数与肺组织湿干比、Fas及FasL蛋白表达呈显著正相关(r分别为0.769,0.820,0.820;P＜0.01).结论:肺动脉栓塞缺血/再灌注可能通过激活Fas/FasL系统,诱导肺组织细胞凋亡,从而导致肺损伤的发生.

Alveolar cells apoptosis and Fas/FasL expression in rabbits after ischemia/reperfusion of pulmonary artery

Objective:To observe the changes of alveolar cells apoptosis and the expression of Fas/FasL protein in pulmonary injury induced by ischemia/reperfusion in rabbbits,and to explore the related mechanism of pulmonary injury.Methods: The left pulmonary arteries of 30 healthy New Zealand rabbits(either sex) were obstructed and reperfused by inflating and discharging gas of 5F Berman sacculus catheter.The rabbits were then randomly divided into 5 groups: sham operation group,ischemia 1 h group,ischemia 2 h group,ischemia 2 h and reperfusion 1 h group,and ischemia 2 h and reperfusion 2 h group.Another 6 healthy rabbits were taken as control.The pulmonary tissues were harvested after experiment and the lung wet/dry ratio was determined.Alveolar cells apoptosis and Fas/FasL protein expression were determined using flow cytometry and immunocytochemistry techniques,respectively.Results: The lung cell apoptosis was obviously increased in ischemia groups compared with that in the control and sham group.The reperfusion after ischemia further increased the cell apoptosis compared with simple ischemia groups,and the apoptosis was positively related with the reperfusion time(P<0.05 or 0.01).Fas and FasL protein expression was significantly higher in ischemia and ischemia/reperfusion group than that in other groups(both P<0.01).Significant positive correlation was found between apoptosis index with lung wet/dry ratio and expression of Fas and FasL(r=0.769,0.820,0.820 respectively,P<0.01).Conclusion: Pulmonary artery ischemia/reperfusion may activate the Fas/FasL system and induce alveolar cells apoptosis,leading to pulmonary damages.