水通道结合膜蛋白-4在大鼠缺血性脑水肿中的表达变化

Changes of aquaporion-4 expression in ischemic brain edema in rats

目的:探讨脑水肿与水通道结合膜蛋白-4(AQP4)表达间的变化关系。方法:阻塞大脑中动脉(MCAO),制作缺血性脑水肿模型,用干湿重法测定不同程度脑水肿状况下梗塞侧脑组织的含水量,用免疫组化及图像分析法观察AQP4阳性细胞数量及面积的变化。结果:MCAO6h后,脑组织中水份开始增加,同时梗塞区部分组织深染,细胞肿大,梗塞区周围见阳性细胞开始增多。随梗塞时间延长,脑水肿加重,AQP4在整个梗塞区的表达增强,梗塞区周围阳性细胞数量递增。MCAO后在松果体血管周围及腺细胞间,以及最后区血管周围和一些阳性细胞染色增强。结论:AQP4与脑水肿的形成有关,并可能与AVP等神经内分泌活动有关。

Objective : To inquire into the correlation between brain edema and changes of aquaporion-4(AQP4) expression. Methods : The middle cerebral artery (MCA) of rats were occluded to make the model of ischemic brain edema and the water contents were detected by dry-wet weight method under the different degrees of brain edema. Computer-aided image analysis was used to quantify the changes in the number and area of the AQP4-positive cell in/or surrounding the occluded areas at the different stages. Results : After 6h of the MCA occlusion, the water content in the occluded brain tissues began to increase. At the same time, the parts of the infarcted areas were stained intensely with the cell swelling and the increase of the AQP4-positive cell. With the prolongation of the infarction time, the degree of edema also increased. Meanwhile, the immunocytochemistry reaction of AQP4 in the infarcted area was intensified and the number of the AQP4-positive cells surrounding the infarcted areas had an increasing tendency. After the occlusion, the perivascular processes were stained more intensely, and the intensified AQP4-positive spots between the pineal gland cells were more obvious, as well as those in the AP. Conclusion : The results indicate that AQP4 is related to the development of brain edema, and AQP4 may be involved in the neuroendocrine activity.