高压氧预适应对老龄大鼠急性全脑缺血的影响摘要目的 观察高压氧预适应（hyperbaric oxygen preconditioning）对老龄大鼠急性全脑缺血后认知功能的影响，磁共振成像分析大脑皮质影像学改变。方法 24只老龄雄性SD大鼠随机分为4组（n=6），正常对照组（C组）、单纯高压氧组（H组）、单纯缺血组（E1组）、高压氧预适应缺血组（E2组），E1组、E2组采用改良Pulsinelli四血管闭塞法建立急性全脑缺血模型， E2组建模前和H组给予连续5天，每天1小时2个标准大气压（2.0ATA）高压氧处理，各组大鼠分别行横断位及冠状位T1WI、T2WI扫描；Morris水迷宫测试学习记忆功能：逃避潜伏期和目标象限游泳时间百分比。结果 C组、H组大脑未见明显缺血梗死灶，E1组双侧皮质区可见明显弧形缺血梗死灶，E2组双侧皮质区也可见弧形缺血梗死区，面积较E1组小。E1组逃避潜伏期长于E2组（P0.05），E2组逃避潜伏期长于C组、H组（P0.05），C组和H组之间差别无统计学意义。E1组目标象限游泳时间百分比较E2组短（P0.05），E2组短于C组、H组，C组和H组之间差别无统计学意义。结论 给予连续高压氧预适应，能减少老龄大鼠急性全脑缺血后超急性期大脑皮质缺血梗死面积，提高全脑缺血后的认知功能水平。关键词：高压氧；预适应；认知功能；老龄大鼠；磁共振成像Effects Of Hyperbaric Oxygen Preconditioning On Aged Rats After Acute Cerebral IschemiaAbstractObjective To investigate the effects of hyperbaric oxygen preconditioning on the cognitive function of aged rats after acute cerebral ischemia，and analyze the changes in the cerebral cortex by magnetic resonance imaging（MRI）Methods 32 aged male SD rats were randomly divided into group C (normal control group), H group (pure hyperbaric oxygen group), E1 group (simply ischemic group), E2 group (hyperbaric oxygen preconditioning ischemia group)，eight rats in each group. E1 and E2 groups were established acute cerebral ischemia model by modified Pulsinelli four-vessel occlusion method. The E2 group before setting up acute cerebral ischemia model and the H group were given hyperbaric oxygen treatment once a day for 5 days. Each group were scan axial line and coronal in T1WI and T2WI. The learning and memory were evaluated with Morris water maze: escape latency and percentage of swimming distance in the platform quadrant.Results There were no obvious ischemic brain infarction in C and H group，there was clearly arc-shaped bilateral cortex ischemic infarct area in E1 group，the ischemic infarct area in E2 was smaller than which the E1 group；Escape latency of E1 group was longer than E2 group（P0.05），and E2 group was longer than C or H group（P0.05）.Swimming distance in the platform quadrant of E1 group was shorter than that of E2 group（P0.05），and E2 group was shorter than C or H group. There were no significant Statistics differences between C and H group.Conclusion Given continuous hyperbaric oxygen preconditioning can reduce the ischemic infarct area in aged rats after acute global cerebral ischemia，improve cognitive function too.Key words: hyperbaric oxygen； ischemic preconditioning； aged rat； cognitive function； magnetic resonance imaging