维生素C对脂多糖急性肺损伤大鼠的保护作用

目的 观察维生素C对大鼠脂多糖性急性肺损伤的保护作用及其机制。方法 健康成年Sprague—Dawley（SD）大鼠24只，雌雄不拘，体重180—200g，随机分成三组：0．9％氯化钠注射液组（NS组）、脂多糖组（LPS组）和维生素C治疗组（VitC组），每组8只大鼠。三组大鼠分别在脂多糖或0．9％氯化钠注射液注入后4h放血处死，测定肺组织丙二醛含量、髓过氧化物酶活性（myeloperoxiase，MPO）及肺湿干重比值（W／D），留少许肺标本固定切片观察病理变化。结果 与NS组比较，LPS组肺组织MDA含量显著增加、MPO活性显著升高，W／D显著增加（t分别=0．01、6．54、6．19，P均〈0．05）；与LPS组比较，VitC组肺组织MDA含量减少、MPO活性明显降低、W／D显著下降（t分别=0．02、7．73、4．61，P均〈0．05）。LPS组肺组织病理切片可见明显急性肺损伤病理改变，维生素C治疗组显示损伤较轻。讨论 大剂量维生素C对脂多糖所致的大鼠急性肺损伤具有保护作用。

Protective effects of vitamin C on acute lung injury induced by lipapalysacchharide in mouse

Objective To investigate the protective effects of vitamin C on the acute lung injury induced by lipapalysacchharide （LPS） in mice. Methods Models of acute lung injury（ALI） in mice were induced by lipopolysacchharide. Twenty - four SD mice weighing 180 - 200 g were randomly divided into 3 groups with 8 animals each： control group received only normal saline ; LPS group received intravenous LPS 5 mg/kg;vitamin C （VitC） group received VitC 4 ml/kg infusion 2 min after intravenous LPS 5 mg/kg. The mice were killed at 4 hr after intravenous LPS or normal saline administration. The lung was used for measurement of wet/dry lung weight ratio and myeloperoxiase （MPO）activity, content of malondialdehyde（MDA） , pathologic changes of lung tissue were observed microscoplcally. Results Obvious ALl pathological manifestation in the lung of LPS group mice was observed compared with NS group ; wet/dry lung weight ratio and MPO activity in lungs increased significantly in LPS group（P 〈 0.05） as well as the content of MDA （P 〈 0. 05）. Compared with LPS group, the pathological manifestation in lungs was ameliorated and wet/dry lung weight ratio, MPO activity and content of MDA decreased significantly in VitC group（P 〈 0.05）. Conclusions Large doses of vitamin C （500 mg/kg）has preventive effect on acute lung injury.