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模拟微重力效应下大鼠不同部位脑组织的氧化应激

陈海龙, 曲丽娜, 李启德, 毕蕾, 黄增明, 李莹辉^*

中国航天员科研训练中心，北京 100193；2 河北省望都县医院，保定 072450

摘要

本研究旨在观察不同时程模拟微重力效应下大鼠脑组织氧化应激的变化，为揭示模拟微重力效应下神经系统氧化应激的发生机制和开发相应的药物防护提供理论基础。将40 只成年雄性Sprague-Dawley (SD)大鼠按体重配对原则随机分为 对照组及不同时间(分别处理7 ，14 ，21 ，28 d)尾悬吊模拟微重力效应组，应用Gries s 法、硫代巴比妥酸反应物法 (thiobarbituric acid reactive substance assay, TBARS)、ELISA法和铁离子还原法(ferric reducing ability of plasma, FRAP)分别检 测大鼠小脑、大脑皮层和海马组织内的活性氮(reactive nitrogen species, RNS)、丙二醛(malondialdehyde, MDA)、硝基酪氨 酸(nitrotyrosine, NT)和总抗氧化能力(total antioxidant capacity, TAC)。结果显示，与对照组相比：(1)小脑组织在尾悬吊7 d 后NT 含量明显升高，之后降低，28 d 再次升高；14 d 后MDA 含量明显增加；21 d 后RNS 含量显著升高，TAC 显著 降低；(2)大脑皮层在尾悬吊14 d 后NT 含量显著升高；21 d 后MDA 含量明显升高，TAC 明显降低；(3)海马组织在尾悬 吊7 d 后RNS 含量明显升高，之后降低，28 d 后再次升高；21 d 后MDA 含量明显升高；28 d 后NT 含量显著上升；7 d 后TAC 明显升高，持续至14 d，然后恢复。上述结果表明，模拟微重力效应使得大鼠脑组织发生了氧化应激，不同部位脑组织对氧化应激的反应程度不同；在对不同时程模拟微重力效应的响应过程中，大鼠脑组织呈现了从适应性反应到不 可逆性损伤的变化历程。

关键词： 微重力; 脑; 氧化应激

分类号：R855

[Simulated microgravity-induced oxidative stress in different areas of rat brain.] [Ariticle in Chinese]

CHEN Hai-Long, QU Li-Na, LI Qi-De, BI Lei, HUANG Zeng-Ming, LI Ying-Hui^*

Laboratory of Space Cellular and Molecular Biology, China Astronaut Research and Training Center, Beijing 100193, China； Wangdu County Hospital, Baoding 072450, China

Abstract

Microgravity is known to produce a number of neurological disturbances during space flight; however, the underlying mechanism of these disturbances is yet to be elucidated. There have been some reports about the increased oxidative stress under microgravity or simulated microgravity. In the present study, we investigated the process of oxidative stress induced by simulated microgravity in different areas of rat brain, which may shed light on the mechanism of neurological disturbances and further neuroprotective research in spaceflight. After adaption for 7 d, 40 healthy male Sprague-Dawley rats were matched for body weight and randomly assigned to control groups (7, 14, 21 and 28 d) and tail-suspended simulated microgravity groups (7, 14, 21 and 28 d). The tail-suspended groups were treated with 30 angels of tail suspension and the control groups were treated similarly to the tail-suspended groups but without tail suspension. After the required times, different structures of rat brain, including cerebellum, cerebral cortex and hippocampus, were harvested and frozen for the further determination. Griess assay, thiobarbituric acid reactive substance (TBARS) assay, competitive ELISA and ferric reducing ability of plasma (FRAP) assay were used for the observation of the changes of reactive nitrogen species (RNS), malondialdehyde (MDA), nitrotyrosine (NT) and total antioxidant capacity (TAC), respectively. As shown in the results, there were different changes in various brain regions after tail suspension compared with control groups. (1) In cerebellum, NT increased after 7 d tail suspension, decreased after 14 d and increased again after 28 d; MDA increased after 14 d; RNS increased and TAC decreased after tail suspension for 21 d; (2) Increase of NT after14 d tail suspension, increase of MDA and decrease of TAC after 21 d were found in cerebral cortex; (3) In hippocampus, RNS increased after tail suspension for 7 d, decreased after 14 d and increased again after 28 d; MDA increased after 21 d; NT increased after 28 d; TAC increased after 7 d and recovered after 21 d. These results suggest that simulated microgravity induced by tail suspension increases the level of oxidative stress in rat brain; however, there are different features in different areas of rat brain. During the response to simulated microgravity, rat brain tissues present a similar process from adaptive response to irreversible oxidative damage.

Key words: Microgravity; brain; oxidative stress

收稿日期：2008-10-07　　录用日期：2008-12-31

通讯作者：李莹辉　　E-mail: linaqu@263.net

引用本文：

陈海龙, 曲丽娜, 李启德, 毕蕾, 黄增明, 李莹辉. 模拟微重力效应下大鼠不同部位脑组织的氧化应激[J]. 生理学报 2009; 61 (2): 108-114.

CHEN Hai-Long, QU Li-Na, LI Qi-De, BI Lei, HUANG Zeng-Ming, LI Ying-Hui. [Simulated microgravity-induced oxidative stress in different areas of rat brain.] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (2): 108-114 (in Chinese with English abstract).