重型脑损伤后AQP4表达与脑水肿的关系

目的观察重型脑损伤后水通道蛋白-4（AQP4）表达变化，及其与脑损伤后脑水肿之间的关系。方法健康成年Wistar大鼠，随机分成创伤性脑损伤（TBI）组和各假手术（SO）组。自由落体硬膜外撞击方法致重度脑创伤模型。于伤后4h、8h、12h、1d、3d、5d、7d取出大鼠脑组织，免疫组化（IHC）和原位杂交（ISH）检测AQP4的表达变化，干湿重法计算脑组织含水量。结果IHC和ISH显示，脑损伤后AQP4在脑组织中的表达上调，1d达高峰，持续至3d后下降，7d接近SO组水平。与SO组相比，除7d亚组外，TBI其余各亚组中AQP4表达水平均明显增高（P〈0、05）。脑损伤后4h脑组织含水量即比SO组增加（P〈0、05），随时间延长，脑组织含水量亦逐渐增加，伤后1-3d达高峰。AQP4表达和脑组织含水量呈正相关，r=0．978，P〈0，01。结论脑损伤后，随着脑水肿加重，AQP4表达上调。提示脑损伤后AQP4的表达变化与脑水肿的形成密切相关，AQP4在损伤后脑水肿的形成中发挥着重要作用。

The relationship between expression of AQP4 and brain edema in patients with trauma to brain

Objective To investigate the changes of AQP4 expression after traumatic brain injury （TBI）, and the relationship between the brain edema and AQP4 expression. Methods Healthy Wistar rats were randomly divided into TBI group and the sham operation （SO） control group. The TBI group was subjected to tranmatic brain injury by the Feeney＇s method. The brains of the animals were taken out 4h, 8h, 12h, 1d, 3d, 5d and 7d after TBI. Subsequently, the expressions of AQP4 and its mRNA were detected with IHC and ISH. The wet - dry weighing method was used to detect the brain water content. Results The expression of AQP4 was positive in cytoplasm and cytomembrane. After TBI, the expression of AQP4 up - regulated, and finally reached a peak 1 - 3d after TBI. The brain water content of brain tissue increased 4h after TBI, and reached its peak also 1 - 3d post - TBI. The brain water content correlated with AQP4 expression positively. Conclusion Both the expression of AQP4 and the brain water content of the brain tissue would increase after TBI, and they are positively correlated indicating that AQP4 may play an important role in the formation and development of brain edema.