急性低压低氧应激导致大鼠认知功能损伤研究

目的:探讨急性低压低氧暴露对大鼠大脑海马损伤、氧化应激以及对认知功能的影响。方法:36只大鼠随机分为3组:常压常氧组(对照组)、模拟海拔4000 m组(4 km组)、模拟海拔6000 m组(6 km组)。比较各组大鼠Morris水迷宫学习与记忆测试成绩、海马神经元凋亡、海马组织中GSH、MDA含量和CAT、SOD的活力。结果:与对照组比较,急性低压低氧组大鼠Morris水迷宫测试成绩明显降低(P<0.05);急性低压低氧组大鼠海马组织中GSH含量、SOD和CAT活力均明显降低(P<0.05),MDA含量明显增加(P<0.01);急性低压低氧组大鼠海马神经元凋亡率明显高于常氧饲养组(P<0.01),以上改变均随海拔升高而更为明显。结论:急性低压低氧应激导致大鼠氧化应激系统失衡,而氧化应激反应直接导致海马神经元的细胞凋亡,并最终导致大鼠学习与记忆等认知能力的下降。

Acute hypobaric hypoxia stress induces cognitive impairment in rats

Objective:To investigate the effect of exposure to acute hypobaric hypoxia on hippocampal damage,oxidative stress and cognitive impairment in rats.Methods: A total of 36 rats were randomly divided into three groups,i.e.normoxic group(control group),simulated 4000 m plateau group and simulated 6000 m plateau group.The Morris water maze learning and memory test was performed to examine the cognitive impairment.The neuronal apoptosis and the content of GSH,MDA,the activities of SOD and CAT in hippocampus were measured.Results: The scores of Morris water maze test in acute hypobaric hypoxia rats were significantly lower than those of control(P<0.05).The GSH content,SOD and CAT activity in hippocampal tissue were significantly decreased(P<0.05).The MDA content and the rate of hippocampal neurons apoptosis was significantly increased(P<0.01).All these changes are more significant with the increase of elevation.Conclusion: Acute hypobaric hypoxia results in imbalance of oxidative stress system in rat,the imblance causes hippocampal neurons apoptosis and eventually lead to impairment of spatial learning and memory abilities.