模拟飞行缺氧与吸氧对小鼠脏器自由基代谢的影响

Effects of Simulated Flight Hypobaric Hypoxia and Oxygen Inhalation on Free Radical Metabolism in Various Organs of Mice.

目的观察了两种模拟飞行条件（１５００ ｍ 轻度低压缺氧和５５００ ｍ 中度低压吸氧重复暴露）下小鼠多脏器自由基代谢变化的特点。方法昆明种小鼠６０ 只，随机分为６ 组（ｎ＝１０）进行缺氧与吸氧实验，实验完毕后，取小鼠尾血做血常规检查。次日，将小鼠断头处死，取脑、心、肺、肝、肾制备匀浆，测定丙二醛（ＭＤＡ） 含量和超氧化物歧化酶（ＳＯＤ）活性。结果１５００ ｍ 轻度低压缺氧重复暴露８ ｗｋ 使肺ＭＤＡ含量显著增高，提示引起小鼠肺的自由基损伤；５５００ ｍ 中度低压吸氧重复暴露８ ｗｋ 后，心肌ＭＤＡ含量、ＳＯＤ活性均明显增高，提示引起小鼠心肌的自由基损伤。结论模拟飞行缺氧与吸氧可以导致小鼠肺及心肌的自由基损伤。

Objective To investigate the effects of two types of simulated flight conditions(hypobaric hypoxia and hypobaric oxygen inhalation) on free radical metabolism in various organs of mice. Method Sixty male Kunming mice were randomly divided into six groups(n=10 each).The experiment comprises two parts.The first part included three groups:normal controls(A1),1500 m hypobaric hypoxia for 4 wk(B1) and 8 wk(C1).The second part included another three groups:normal control(A2),5500 m hypobaric oxygen inhalation for 4 wk(B2) and 8 wk(C2).The exposure time in hypobaric chamber was 2 h/d,3 d/wk.After experiment,caudal blood was taken for routine examination.The mice were decapitated on the next day and brain,heart,lung,liver and kidney homogenates were prepared for measuring malondialdehyde(MDA) content and superoxide dismutase(SOD) activity. Result Lipid peroxides in lung was significantly increased in C1 group, and the content of myocardial MDA and myocardial SOD activities in C2 group were markedly higher than those in A2 group.There were no significant differences among body weights, mean corpuscular indices and hemoglobin content in the normal control,hypobaric hypoxia and hypobaric oxygen inhalation groups.It demonstrates that repeated mild hypobaric hypoxia for 8 wk causes free radical damage of lung and repeated exposure to 5500 m hypobaric oxygen inhalation for 8 wk may lead to myocardial peroxidative injury in mice. Conclusion Simulated flight hypobaric hypoxia and oxygen inhalation may lead to free radicals damage of lung and myocardial peroxidative injury in mice.