缺血性脑水肿与水通道蛋白-4表达关系的研究

目的 探讨早期缺血性脑水肿后水通道蛋白-4（AQP-4）表达水平的动态变化及其与脑水肿形成的关系，进一步探讨脑水肿的发生机制。方法 取健康成年雄性SD大鼠62只，月龄3～4个月，体重250～300g，随机分为实验组（根据缺血时间分为1h，3h，6h，24h和72h五组）、对照组（包括假手术组和正常组）。参考Zea—Longa线栓法建立大鼠局灶性脑缺血模型，于术后应用干湿重法测定不同程度脑水肿状况下脑组织的含水量，应用Westernblot技术对AQP-4蛋白表达及其与脑水肿的关系进行相关性观察。结果脑缺血1h脑组织的含水量即开始增加（P〈0．05），并随着时间的推移逐渐增加。AQP-4蛋白在缺血组织表达亦增强，缺血1h即开始增强，24h显著增加，72h仍然高于正常水平。结论 AQP-4是影响缺血性脑水肿的重要因素。

A Correlative Study Between the Ischemic Brain Edema and the Expression of Aquaporin- 4

Objective To explore the change of AQP-4 expression at early stage of the post-ischemic brain edema and the correlation to brain edema,in order to approach the pathogenesy of intracranial edema.Methods 62 healthy Wistar male rats aged 3 to 4 months with a body mass between 250g to 300g were selected.They were divided randomly into experiment group(1h,3h,6h,24h and 72h subgroups according to the time exposed to ischemia)and control group(including shamed operation subgroup and normal group).The model of middle cerebral artery occlusion was performed with intra luminal filament occlusion refer to Zea-Longa's method.The sample were analyzed by the water contents were detected by dry-wet weight method under the different degrees of brain edema,and Western Blot analysis were applied to analyze the AQP-4 expression,in order to observe the correlation to the brain edema.Results The water contents commence increase at 1h after cerebral ischemia(P<0.05),and combine gradual increment along with change of time.Expression of AQP-4 increased at 1h after cerebral ischemia, and increased significantly on 24h,and at the 72h is still higher than normal level.Conclusions AQP-4 plays an important role in post-ischemic edema formation.