Li Jiasi, Liu Wenwu, Ding Suju, Xu Weigang, Guan Yangtai, Zhang John H, Sun Xuejun
Department of Neurology, Changhai Hospital,174 Changhai Road, Shanghai 200433, PR China.
Brain Res. 2008 May 19;1210:223-9. doi: 10.1016/j.brainres.2008.03.007. Epub 2008 Mar 12.
The present study examined the hypothesis that cerebral ischemic tolerance induced by hyperbaric oxygen preconditioning (HBO-PC) is associated with an increase of antioxidant enzyme activity. Male Sprague-Dawley rats (250-280 g, n=74) were divided into sham, middle cerebral artery occlusion (MCAO) for 90 min, and MCAO plus HBO-PC groups. HBO-PC was conducted four times by given 100% oxygen at 2.5 atmosphere absolute (ATA), for 1 h at every 12 h interval for 2 days. At 24 h after the last HBO-PC, MCAO was performed and at 24 h after MCAO, neurological function and Nissl Staining were performed to evaluate the effect of HBO-PC. Malondialdehyde (MDA) content, activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) sampled from the hippocampus, ischemic penumbra or core of cortex were measured. HBO-PC decreased mortality rate, improved neurological recovery, lessened neuronal injury, reduced the level of MDA and increased the antioxidant activity of CAT and SOD. These observations demonstrated that an upregulation of the antioxidant enzyme activity by HBO preconditioning plays an important role in the generation of tolerance against brain ischemia-reperfusion injury.
高压氧预处理（HBO-PC）诱导的脑缺血耐受性与抗氧化酶活性增加有关。将雄性Sprague-Dawley大鼠（250-280克，n=74）分为假手术组、大脑中动脉闭塞（MCAO）90分钟组和MCAO加HBO-PC组。HBO-PC通过在2.5绝对大气压（ATA）下给予100%氧气进行4次，每12小时间隔1小时，共2天。在最后一次HBO-PC后24小时进行MCAO，在MCAO后24小时进行神经功能和尼氏染色以评估HBO-PC的效果。测量从海马体、缺血半暗带或皮质核心取样的丙二醛（MDA）含量、过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-px）的活性。HBO-PC降低了死亡率，改善了神经功能恢复，减轻了神经元损伤，降低了MDA水平，并增加了CAT和SOD的抗氧化活性。这些观察结果表明，HBO预处理对抗氧化酶活性的上调在对脑缺血再灌注损伤的耐受性产生中起重要作用。
