摘要
目的探讨亚甲蓝是否可以保护急性缺氧引起的脑损伤。方法筛选出亚甲蓝最佳剂量0.5mg/kg后,将实验小鼠分为常氧组、常氧+亚甲蓝组、低氧组和低氧+亚甲蓝组4组,低氧组和低氧+亚甲蓝组小鼠于低氧前30min给予腹腔注射脂多糖(lipopolysaccharide,LPS),常氧+亚甲蓝组和低氧+亚甲蓝组给予腹腔注射亚甲蓝(0.5mg/kg),注射后立即将低氧组和低氧+亚甲蓝组小鼠置于低压低氧实验动物舱中6h;其他组小鼠给予腹腔注射生理盐水作为对照。以脑组织干湿比法测定脑组织含水量;Morris水迷宫检测小鼠空间记忆;HE染色观察脑组织病理学改变以及Western blot检测脑组织自噬活性。结果 (1)与常氧组相比,低氧组小鼠脑组织含水量升高[(78.62±0.01)%vs.(78.42±0.01)%,P<0.01],低氧+亚甲蓝组(78.44±0.02)%]小鼠脑组织含水量低于低氧组(P<0.05);(2)与常氧组相比,低氧组小鼠穿越平台次数明显减少(1.00±0.25vs.2.33±0.28,P<0.01),在靶象限的运动距离明显减少[(2.59±0.40)mvs.(4.56±0.52)m,P<0.01];与低氧组相比,低氧+亚甲蓝组小鼠穿越平台次数明显增加(2.36±0.41,P<0.05),在靶象限的运动距离增加[(4.08±0.39)m,P<0.01];(3)低压低氧处理后,(1)低氧组与常氧组以及低氧+亚甲蓝组与低氧组相比,小鼠脑组织结构未发现明显病理性损伤;(2)与常氧组相比,低氧组小鼠脑组织中自噬分子Beclin1(0.65±0.05 vs.0.93±0.04,P<0.01)和LC3Ⅱ/Ⅰ(0.34±0.03 vs.0.66±0.01,P<0.01)表达明显减少,而低氧+亚甲蓝组小鼠脑组织Beclin1(0.94±0.04 vs.0.65±0.05,P<0.01)和LC3Ⅱ/Ⅰ(0.90±0.01 vs.0.34±0.03,P<0.01)表达高于低氧组。结论亚甲蓝可能通过诱导脑组织细胞的自噬而保护急性缺氧引起的脑组织损伤。
Objective After screening out the best effects dosage of methylene blue,To investigate whether methylene blue(MB)protects the brain damage induced by hypobaric hypoxia.Methods After screening out the best effects dosage of methylene blue,all animals were randomly separated into four groups:normoxia,normoxia+MB,hypoxia,hypoxia+MB.Both hypoxia and hypoxia+MB groups were interperitoneally injected with LPS 30 min prior to exposure to hypobaric hypoxia.The mice in the normoxia+MB and hypoxia+MB groups were interperitoneally administrated with MB,and simultaneously the mice in the normoxia and hypoxia groups were interperitoneally administrated with normal saline.Immediately after that,mice in the hypoxia and hypoxia+MB groups were exposed to hypobaric hypoxia(6000 m)for 6 h.The brain water content,spatial memory,histopathology and autophagic activity were detected by Dry/Wet weight,Morris Water Maze,Hematoxylin-Eosin staining and Western blot,respectively.Results (1)Compared to the normoxia group,exposure to hypobaric hypoxia increased the brain water content in the hypoxia group[(78.62±0.01)%vs.(78.42±0.01)%,P<0.01],while MB treatment ameliorated the elevation of brain water content[(78.44±0.02%vs.(78.62±0.01)%,P<0.05];(2)Compared to the normoxia group,there was a decline in spatial memory of mice of the hypoxia group,consisting of the considerable decrease in the number of crossing times(1.00±0.25 vs.2.33±0.28,P<0.01)and the pathlength in the quadrant[(2.59±0.40)m vs.(4.56±0.52)m,P<0.01].While the number of crossing times(2.36±0.41 vs.1.00±0.25,P<0.05)and the pathlength in the target quadrant[(4.08±0.39)m vs.(2.59±0.40)m,P<0.01]were markedly improved in the hypoxia+MB group;(3)No obvious cerebral structure change was observed by Hematoxylin-Eosin staining in the treatment of hypobaric hypoxia combined with LPS;however,the treatment caused the decrease of autophagic activity in the brain,there was a dramatic decrease of the expresence of autophagy marker such as Beclin1(0.65±0.05 vs.0.93±0.04,P<0.01)and LC3Ⅱ/Ⅰ(0.34±0.03 vs.0.66±0.01,P<0.01)in the hypoxia group,while the pression of Beclin1(0.94±0.04 vs.0.65±0.05,P<0.01)and LC3Ⅱ/Ⅰ(0.90±0.01 vs.0.34±0.03,P<0.01)were upregulated obviously.Conclusions The protection of MB against the brain damage induced by hypobaric hypoxia is probably mediated by increasing the autophagic activity in the brain.
作者
巩生辉
何云凌
赵名
赵彤
成祥
吴奎武
范明
吴丽颖
朱玲玲
KONG Shenghui;HE Yunling;ZHAO Ming;ZHAO Tong;CHENG Xiang;WU Kuiwu;FAN Ming;WU Liying;ZHU Lingling(Guangxi Medical University,Nanning 530021,China;Institute of Radiation Medicine,Beijing 100850,China.;Institute of Military Cognition and Brain Science,Academy of Military Medical Sciences Academy of Military Science of the Chinese People's Liberation Army,Beijing 100850,China)
出处
《中国神经免疫学和神经病学杂志》
CAS
北大核心
2018年第2期108-112,124,共6页
Chinese Journal of Neuroimmunology and Neurology
基金
国家自然科学基金(81430044)
北京市科委项目(Z161100000216134)
国家自然科学基金面上项目(317H321,31271211)
关键词
高原
低氧
亚甲蓝
自噬
high altitude
hypoxia
methylene blue
autophagy
作者简介
通讯作者:吴丽颖,Email:liyingwu_china@163.com;通讯作者:朱玲玲,Email:linglingzhuamms@126.com
