大鼠弥漫性脑损伤后水通道蛋白4的表达

Expression of Aquaporin 4 in Diffuse Brain Injury of Rats

目的观察大鼠弥漫性脑损伤后水通道蛋白4(aquaporin 4,AQP4)的表达,探讨其在脑水肿发生中的作用。方法参照Marmarou的打击负荷伤模型,建立大鼠弥漫性脑损伤动物模型。用干湿重法测定脑组织含水量,用伊文思蓝(Evans blue,EB)检测血脑屏障通透性的变化,运用免疫组织化学方法观察AQP4的表达。结果打击后3 h脑组织含水量增加,24 h达到高峰。脑组织EB含量伤后明显增加,12 h达到高峰。AQP4于打击后3 h表达明显增强,24 h达到高峰,AQP4阳性表达的胶质细胞数量明显增多。结论大鼠弥漫性脑损伤后血脑屏障通透性的增加及AQP4表达的增强促进脑水肿的发生,AQP4在胶质细胞的表达变化可用于辅助诊断弥漫性脑损伤。

Objective To observe the expression of aquaporin 4 （AQP4） in diffuse brain injury （DBI） of rats and to explore the corresponding effect of AQP4 for brain edema. Methods The rat model of DBI was established using Marmarou＇s impact-compression trauma model. Brain water content was measured by dry-wet weight method. Blood-brain barrier permeability was evaluated by Evans blue （EB） staining. Immunohistochemical method was used to observe the expression of AQP4. Results Brain water content increased after 3 h and peaked at 24 h after DBI. Brain EB content significantly increased and peaked at 12h after DBI. The expression of AQP4 significantly increased after 3 h and peaked at 24 h after DBI, and the number of AQP4 positive astrocytes increased. Conclusion The increment of the permeability of blood-brain barrier and the expression of AQP4 may contribute to the development of brain edema in rat DBI. The change of AQP4 expression in astrocytes may also contribute to determine DBI.