Abstract: Objective To assess the effect of durative-9-hour hyperbaric oxygenation (HBO) on cerebral infarct volume in the treatment of rats with permanent middle cerebral artery occlusion (MCAO) in superearly stage.Methods Using the intraluminal suture method, we subjected male Sprague-Dawley rats topermannent MCAO model, then the rats were randomly divided into control group and HBO group.Three hours after MCAO, the rats in the HBO group stayed in the hyperbaric cabin with a pressure of 0.2Mpa for 9 hours. Thirteen hours and 5d after MCAO we calculated the cerebral infarct volume with triphenyltetrazolium chloride(TTC) staining and measured the expression of vascular endothelial growth factor (VEGF) using immunohistochemical staining.Results (1) On 13h, there was no significant difference in the infarct volume between the two groups(P >0.05), and at 5d the volume of control group was larger than that on 13h(P <0.05), while in HBO group the volume was smaller than that in control group (P <0.05). (2) The expression of VEGF increased in both groups on 13h point, and there was no significant difference between the two groups(P >0.05). At 5d after MCAO, the expression of VEGF in control group decreased significantly compared with that on 13h point(P <0.01), but in HBO group the expression of VEGF increased significantly when compared with that on 13h point and that in control group at 5d point(P <0.01).Conclusion Durative-9h HBO protocol in super-early stage can reduce the volume of cerebral infarction in rats. Stimulating more production of endogenous VEGF may be one of the mechanisms.

Key words: Infarction; Middle cerebral artery; Hyperbaric oxygenation; Vascular endothelialgrowth factor

摘要： 目的 本研究主要观察高压氧（HBO）单次9 h超早期治疗对永久性大脑中动脉阻塞（MCAO）大鼠脑梗死体积的影响。方法 制作SD大鼠永久性MCAO模型，随机分为对照组、HBO组，HBO组大鼠于模型制备成功后3 h予单次9 h HBO治疗，压力0.2 MPa。模型成功后13 h、5 d，分别将大鼠脑组织进行2,3,5苯四氮唑（TTC）染色测定梗死体积，免疫组织化学染色测定脑组织中血管内皮生长因子（VEGF）的表达情况。结果 （1）13 h时，两组大鼠脑梗死体积相差不大（P >0.05）；5 d时，对照组大鼠脑梗死体积较13 h时增大（P <0.05），而HBO组变化不大（P >0.05），组间比较，HBO组较对照组脑梗死体积缩小（P <0.05）。（2）13 h时，对照组和HBO组VEGF均有表达，两组间差异无统计学意义（P >0.05）；5 d时，对照组VEGF表达较13 h时明显减少（P <0.01），而HBO组VEGF表达明显高于13 h，而且显著高于对照组5 d水平（P <0.01）。结论 单次9 h HBO超早期治疗可缩小大鼠脑梗死体积，其机制可能与HBO提高内源性VEGF表达有关。

关键词: 梗死; 大脑中动脉; 高压氧; 血管内皮生长因子