兔肺动脉栓塞再灌注肺泡细胞凋亡及调控基因的实验研究

目的 探讨兔肺动脉栓塞／再灌注损伤中的细胞凋亡及其基因调控机制。方法 健康新西兰白兔36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6组：对照组，假手术组，肺栓塞1h组、肺栓塞2h组，肺栓塞2h再灌注1h组、肺栓塞2h再灌注2h组。实验结束取肺组织，测定肺组织湿干比，采用流式细胞分析法检测肺组织细胞凋亡率和免疫组织化学法检测肺上皮细胞Bax、Bcl-2、Fas／FasL蛋白表达的变化。结果兔肺动脉栓塞时肺组织细胞凋亡明显增加，再灌注后1h、2h凋亡细胞继续增加，并随着再灌注时间延长而增加（P〈0．05），Bax、Fas及FasL蛋白表达在肺动脉栓塞缺血及再灌注后明显增加（P〈O．01）。肺泡上皮细胞凋亡指数与肺组织湿干比、Bax、Fas、FasL蛋白表达之间存在非常显著的正相关关系（r=0．721，0．806，0．820，0．820；P〈0．01），与Bcl-2、Bcl-2／Bax比值呈显著负相关关系（r=-0．602，-0．829；P〈0．01）。结论肺动脉栓塞／再灌注中诱导肺组织细胞凋亡增加，肺组织细胞凋亡和Bax、Bcl-2，Fas、FasL系统活化可能参与了肺栓塞缺血再灌注肺损伤的发生。

Change of apoptosis of alveolar cells and expression of apoptotic related genes in ischemia/reperfusion induced pulmonary injury: an experimental pulmonary embolism with rabbits

Objective To evaluate the changes of alveolar cells apoptosis and the expression of related genes in pulmonary injury induced by ischemia/reperfusion (I/R) in acute experimental pulmonary embolism of rabbits. Methods The left lung artery of rabbits were obstructed by inflating gas of 5F Berman sacculus catheter, then the gas of sacculus was put out to result in blood reperfusion. Thirty-six New Zealand rabbits of either gender and weighing 2.5 to 3.0 kg were studied, and randomly divided into six groups: control group (control), sham operation group (sham), ischemia 1h group (I 1h), ischemia 2h group (I 2h), ischemia2h and reperfusion 1h group (IR 1h), ischemia 2h and reperfusion 2 h group (IR 2h). Alveolar cells apoptosis and Bax, Bcl-2, Fas/FasL protein expression were studied By using flow-cytometry and immunocytochemistry techniques. Results The lung apoptosis cell number was increased in ischemia groups compared with control and sham group. The reperfusion after ischemia further increased the apoptosis cell numbers compared with simple ischemia, and the longer time reperfusion,the larger number of cell apoptosis. Bax, Bcl-2, Fas and FasL protein expression were significantly higher in ischemia, ischemia/reperfusion group than that in those of control groups (P<0.01, respectively). There were significant positive correlation between cell apoptosis index and lung wet/dry ratio, expression of Bax, Fas, FasL (r=0.721, 0.806, 0.820, 0.820, P<0.01, respectively) and negative correlation with Bcl-2, Bcl-2/Bax (r=-0.602, -0.829; P<0.01). Conclusion Alveolar epithelial cells apoptosis was increased in rabbit pulmonary ischemia and ischemia/reperfusion model. Bax, Bcl-2, Fas and FasL system may regulate the alveolar epithelia cells apoptosis and involved in the pathophysiology of ischemia /reperfusion lung injury.