机械通气致大鼠急性肺损伤时肺组织及血MDA、SOD的变化

目的观察机械通气致大鼠肺损伤时肺组织及血MDA和SOD含量变化,探讨氧化应激在大鼠急性肺损伤发病机制中的作用。方法24只SD雄性大鼠随机分为自主呼吸组（A组）和机械通气组（B组）,每组12只。A组采用自主呼吸,B组采用大潮气量机械通气。于通气后4 h放血处死动物,收集肺组织和肺灌洗液标本,测定肺灌洗液中蛋白总量、白细胞计数和肿瘤坏死因子α（TNF-α）;测肺湿/干重比（W/D）;测定肺组织和血中MDA及SOD含量;取肺组织观察病理变化。结果与A组相比,B组肺灌洗液中白细胞计数、TNF-α和蛋白总量明显增加（P〈0.01）;肺组织和血中MDA含量上升,SOD含量下降（P〈0.01）;肺W/D增加（P〈0.01）。肺组织出现明显病理组织学损伤。结论机械通气致急性肺损伤时肺组织发生了强烈的氧化应激损伤,同时伴有机体抗氧化能力相对不足。

Changes of MDA and SOD in ventilator-induced lung injury in rats

Objective To observe changes of MDA and SOD levels, and to study the effect of oxidative stress reaction in pathogenesis of ventilator - induced lung injury （VILI） in rats. Methods Twenty - four male Sprague - Dawley rats were randomly divided into two groups （n = 12 each） ： group A received room air without mechanical ventilation, group B received large tidal volume with mechanical ventilation. After 4 h of ventilation, rats were sacrificed and the lung lavage liquid and lung tissue were collected and stored with correct methods. The measured indexes include total protein, WBC and TNF-α in bronchoalveolar lavage fluid （BALF）, Wet- to- dry weight ratio （W/D） of lung, the levels of MDA, SOD in the blood and homogenate of harvested lung were assayed respectively. Lung pathological change was observed by microscope. Results Total protein, TNF -α and WBC in BALF and the levels of MDA in the lung and blood of group B were markedly higher than those of Group A （P 〈0.01 ）. The levels of SOD in the lung and blood of group B were significantly lower than those of group A （ P 〈 0.01 ）. Conclusion Strong oxidative stress is found in lung tissues of rats with VILI, and body＇s anti - oxidative stress abilities is deficient relatively at the same.