新生大鼠缺氧缺血性脑损伤AQP-4表达及依达拉奉治疗效果的研究

目的：探讨新生大鼠缺氧缺血性脑损伤（hypoxic-ischemic brain damage,HIBD）后脑组织水通道蛋白-4（AQP-4）的表达变化及依达拉奉（edaravone）对其治疗效果的影响。方法：将7日龄Wistar大鼠120只随机分为3组：假手术组、缺氧缺血模型组（HIBD组）及依达拉奉治疗组,每组各40只。每组根据处死的时间不同又分5个亚组：6、24h、3、5、7d组,每亚组各8只,各组分别于不同时间点处死动物,测脑组织含水量,并采用免疫组化方法检测AQP-4的表达。结果：AQP-4在缺氧缺血6h即增强,3d达高峰,5～7d逐渐降低（P〈0.01）;治疗组各时间点AQP-4表达水平较HIBD组明显降低（P〈0.01）。结论：AQP-4参与了HIBD脑水肿的发生发展过程,依达拉奉可降低AQP-4的表达,从而减轻脑水肿,这可能是其脑保护作用机制之一。

Expression of AQP-4 and effects of edaravone in neonatal rats with hypoxic-ischemic brain damage

Objective： To probe into the expression of AQP-4 in brain tissue after hypoxic-ischemic brain damage（HIBD） in neonatal rats and the effect of Edaravone on the treatment of HIBD. Methods： A total of 120 seven-day-old Wistar rats were randomly divided into three groups （n=40）, sham-operated group, hypoxic-ischemic brain damage （HIBD） group and Edaravone-treated group. Each group were divided into five sub-groups （n=8 in each subgroup） based on different time points after HIBD（6,24 h,3,5,7 d）. Animals were sacrificed at different time points. Changes of brain water content were determined. And immunohistochemical technique was used to determine the expression of AQP-4. Results： The expression of AQP-4 increased significantly on 6 h after HIBD, the peak reached on 3 d and 5-7 d gradually decreased（P〈0.01）. The level of AQP-4 expression in treatment group was significantly lower than HIBD group at each time point （P〈0.01）. Conclusion： AQP-4 involves in the occurrence and development process of cerebral edema after HIBD. Edaravone can reduce the expression of AQP-4, so as to alleviate brain edema, which may be the one of the mechanisms of brain protection.