氧自由基在高原暴露下血脑屏障通透性改变中的作用及其与高原脑水肿的关系  

Relationship Between the Influence of Oxygen Free Radical on Permeability of the Blood-brain Barrier under High Altitude Environmental Exposure and High Altitude Cerebral Edema

作　　者：周其全[1] 王静[2] 汪云利[2] 李爱冬[2] 程丽[2] 

机构地区：[1]第三军医大学高原军事医学系病理生理与高原生理学教研室,重庆400038 [2]成都医学院基础医学部病理学与病理生理学教研室

出　　处：《中国微循环》2007年第3期149-153,共5页Journal of Chinese Microcirculation

基　　金：军队"十五"指令性课题资助(01L062);四川省教育厅"十五"重点课题(03Z03)

摘　　要：目的 观察高原环境暴露下脑内氧自由基与脑含水量的变化，探讨氧自由基在高原脑水肿血脑屏障改变中的作用。方法 取不同海拔梯度下小鼠脑组织匀浆化学法测定脑内SOD、MDA、GSH和GSH-PX活性，比色法测定脑组织内伊文思蓝（EB）含量，湿干比值法测定脑含水量。结果 高原暴露下，小鼠脑内SOD、MDA、GSH活性是随着海拔增高而逐渐增高，随着时间延长而逐渐增高，以暴露于5000m的高海拔区第7-9d增高最明显，而GSH-PX则相反。与此同时，脑内EB含量和脑内含水量逐渐增高。脑内氧自由基活性与脑内EB含量和脑含水量之间有明显的正相关关系。结论 氧自由基在高原脑水肿形成中起了重要作用，是高原环境下血脑屏障通透性增高的重要因素。Objective To observe the changes of oxygen free radical（OFR） and water content in brain and the influence of OFR on permeability of the blood-brain barrier（BBB） under high altitude environmental exposure. Methods Mice were exposed to different altitude gradients, then brain tissue homogenate was prepared, and the activities of superoxide dismutase（SOD）, malondialdehyde（MDA）, glutathione（GSH） and glutathione peroxidase（GSH-PX） in brain tissue homogenate were measured by chemical methods. The evans blue （EB） content in brain tissue was determined by colorimetry and the wet weight/dry weight ratio（W/D） was used to express the water content in brain. Results With altitude going up, the activities of SOD, MDA and GSH in the brain of mice rose, and they also rose gradually with time prolonging under high altitude hypoxia ex- posure. Their most obvious rise was seen during 7-9 days after ascending 5000m high altitude regions. The GSH-PX rose in the first-two days at 5000m high altitude, but reduced from the third day after entry to this high altitude. At the same time, the EB and water content in the brain of mice showed the same change trends. Therefore, the OFR activity and EB content as well as water content in brain showed an evitdently linear relationship. Conclusion The OFR plays an important role in high altitude cerebral edema. It is also a critical inducing factor in the change of permeability of BBB under high altitude environmental exposure.

关 键 词：高原暴露 血脑屏障通透性 脑含水量 氧自由基 高原脑水肿 

分 类 号：R742.7[医药卫生—神经病学与精神病学]