细胞凋亡在呼吸机相关性肺损伤中的作用

Effects of cell apoptosis on ventilator-induced lung injury

目的:观察细胞凋亡在呼吸机相关性肺损伤(ventilator-induced lung injury,VILI)中的作用,探讨呼吸机相关性肺损伤的发生机制。方法:将50只健康雄性Wistar大鼠随机分为对照组和肺损伤组。对照组插管后不进行机械通气;肺损伤组插管后机械通气,潮气量为20 ml.kg-1,频率为50次.min-1,吸呼比为1∶3,FiO2为21%,通气时间为5 h。观察实验前后动脉氧分压变化,采用Annexin-V/PI双染方法检测肺组织及肺泡灌洗液细胞凋亡率。取各组大鼠左全肺称湿重,置于烘箱内80℃干烤24 h后称干重,并计算肺组织湿/干重(W/D)值;制备肺组织切片进行病理学观察。结果:两组大鼠动脉氧分压差异无统计学意义(P>0.05);肺损伤组肺组织及肺泡灌洗液细胞凋亡明显增加(P<0.01),肺组织W/D值显著高于对照组(P<0.01);肺损伤组肺组织病理切片可见肺组织水肿。结论:机械通气可导致肺损伤,细胞凋亡可能在VILI发生、发展过程中起重要作用。

Objective： To observe the effects of cell apoptosis on ventilator-induced lung injury （VILI） and dis- cuss the mechanisms of VILI. Methods： Fifty healthy male Wister rats were randomly divided into control group and lung injured group. The control group was not given mechanical ventilation after intubation, whereas the lung- injured group was given mechanical ventilation（tidal volume ：20 ml ~ kg^-1, frequency： 50 times min^-1, inspiratory and expiratory rate： 1： 3, FiO2：21%, ventilation time： 5 hours）. Changes of arterial partial pressure of oxygen be- fore and after experiment were observed. Cell apoptosis in lung tissue and bronchia alveolus lavage fluid was detec- ted by means of annexin V/PI staining method. The whole left lung of the rats from two groups was taken wet weight, and dry weight was taken after being put into an oven and baked with 80 ℃ for 24 hours, then calculating the wet and dry weight （W/D） ratio of lung tissue. Lung tissue sections were prepared for biopsies. Results： There were no significant differences in arterial partial pressure of oxygen between the two groups （ P 〉 0.05 ）. Cell apoptosis in lung tissue and bronchia alveolus lavage fluid significantly increased in lung injured group（P 〈 O. 01 ）. The W/D ratio of lung tissue in lung injured group was higher than that in the control group （P 〈 0.01 ）. Lung tis- sue edema could be fined in lung tissue biopsy of lung injured group. Conclusions： Mechanical ventilation couldcause lung injury. Cell apoptosis may play an important role in the occurrence and development of ventilator induced lung injury.