高压氧对大鼠脑缺血区线粒体氧自由基影响的实验研究  

Effect of hyperbaric oxygen treatment on mitochondrial free radicals after transient focal cerebral ischemia in rats

作　　者：楼敏[1] 王季华[1] 钱琼秋[2] 闻树群[1] 丁美萍[1] 

机构地区：[1]浙江大学医学院附属第二医院神经内科,浙江杭州310009 [2]浙江大学园艺系,浙江杭州310029

出　　处：《浙江大学学报（医学版）》2008年第5期437-443,共7页Journal of Zhejiang University(Medical Sciences)

基　　金：国家自然科学基金(30500175);浙江省教育厅课题

摘　　要：目的:研究高压氧(HBO)对大鼠脑缺血区线粒体氧自由基及抗自由基酶的影响。方法:参照改良的Koizumi方法,在激光多普勒血流仪监测局部脑血流的条件下,建立线栓法大鼠局灶性脑缺血模型,缺血90min后再灌注,缺血后3h高压氧治疗(3个标准大气压,1h),缺血后24h分别取缺血核心区和半暗区脑组织,差速离心提取线粒体,进行超氧阴离子自由基(O2.)生成速率、H2O2含量、丙二醛(MDA)含量测定,以及线粒体超氧化歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)和还原型谷胱甘肽(GSH)含量测定。结果:脑缺血再灌注24h后缺血半暗区和核心区线粒体的H2O2、O2.、MDA的含量较正常对照组明显增加,而SOD、GSH-PX活性以及GSH的含量较正常对照组明显下降(P<0.05)。经HBO治疗后,缺血半暗区线粒体O2.含量增加(P<0.05),SOD活性提高(P<0.05),而MDA含量减少(P<0.05);缺血核心区线粒体O2.含量增加(P<0.05),SOD活性提高(P<0.05),但MDA含量不变。HBO治疗对脑缺血区的H2O2、GSH-PX和GSH作用无影响。结论:在脑缺血时间窗内,HBO治疗能增加脑缺血区线粒体自由基生成,提高线粒体抗自由基酶活性;能抑制脑缺血半暗区线粒体的脂质过氧化损伤,但对核心区作用不明显。提示线粒体的功能状态在HBO治疗后的自由基反应中起重要作用。Objective. To mitochondrial free radicals af rats were randomly assigne investigate te d r transient the effect of hyperbaric oxygen （HBO） therapy on focal cerebral ischemia in rats. Methods： The male SD into two groups, control and HBO groups. All animals were subjected to 90 min intra-luminal middle cerebral artery occlusion （MCAO）with the regional cerebral blood flow monitored in vivo by laser Doppler flowmetry. HBO treatment was performed in a pressure chamber with 100% O2（3 ATM 1 h） 3 h after ischemia. Twenty-four hours after ischemia,mitochondria in the ischemic core and penumbra were isolated and the contents of H2O2, O2^-,MDA,SOD,GSH-PX and GSH in mitochondria were measured respectively. Results. After cerebral ischemia-reperfusion, contents of mitochondrial H2O2, O2^-, MDA increased, while the SOD,GSH-PX and GSH in the mitochondria decreased significantly both in the ischemic core and the ischemic penumbra,compared with those in the normal controls （P〈0.05）. In the ischemic penumbra,HBO therapy increased significantly the content of O2^-（P 〈 0.05）, enhanced the activity of SOD,and decreased the level of MDA （P〈0.05）. However,HBO therapy did not change the level of MDA,though it also increased the content of O2^-and the activity of SOD in the ischemic core. HBO therapy had no significant effect on the contents of H2O2,GSH-PX and GSH in the ischemic mitochondria. Conclusions. HBO therapy initiated early after acute transient cerebral ischemia in rats can increase the mitochondrial free radicals level,but also increase the activity of the anti-radical enzymes. HBO treatment inhibits the lipid peroxidation damage of mitochondria in the ischemic penumbra, but not in the ischemic core, which indicates that the mitochondrial function plays a role in the reaction of the free radical in the ischemic area after HBO therapy.

关 键 词：高压氧 脑缺血/治疗 脑缺血/病理学 线粒体 活性氧/代谢 再灌注损伤/病理学 再灌注损伤/治疗 疾病模型 动物 

分 类 号：R459.6[医药卫生—治疗学] R743[医药卫生—临床医学]