AQP4与PKC在大鼠CIR后脑水肿模型中的变化及作用

目的通过研究大鼠局灶性脑缺血再灌注后水通道蛋白4（AQP4）、蛋白激酶C（PKC）表达水平的变化,来探讨两者与脑水肿之间的关系。方法通过线栓法复制大鼠大脑中动脉缺血（MCAO）再灌注模型,动物随机分为正常对照组（Norm）、假手术组（Sham）、缺血再灌注组（CIR）。参照Garcia JH法进行神经功能缺损评分、用Elliot法检测脑组织含水量、免疫组化法检测AQP4及PKC的表达。结果 CIR后6h即有神经功能缺损,脑含水量在CIR12h明显升高,1~3d时达到高峰;AQP4表达在早期水平降低,从12h逐渐升高,至CIR 24h明显升高,3d达高峰;PKC在CIR后6h开始持续性升高,至第5d仍保持较高水平。结论早期的细胞源性脑水肿可能和PKC的升高有关,后期的血管源性脑水肿可能和AQP4的升高相关。

Effects and Variation of AQP4 and PKC on the Brain Edema Model after Cerebral Ischemic Reperfusion in Rats

Objective By studying the changes of expression levels of aquaporin4 （AQP4） and protein kinase C （PKC） after focal cerebral ischemia-reperfusion in rats to investigate the relation among AQP 4 ,PKC and brain edema. Methods The model of middle cerebral artery （MCA） of rats was duplicated by using the suture method.The rats were randomly divided into normal control group （Norm ） ,sham-operation group （Sham ） ,cerebral ischemia reperfusion group （CIR ）.Scores of neurofunctional defect were graded according to Garcia JH method ,Elliot method was used to measure water content in brain tissue ,the expression of AQP4 and PKC in brain tissue was observed by immunohistochemistry. Results After cerebral ischemia-reperfusion （CIR ） ,Neurofunctional defect occurred after 6h.Water content in brain tissue increased after CIR 12h ,which was up to highest point after 1-3days.The expression levels of AQP4 decreased in early ,then the levels increased gradually since 12h later ,obviously increased CIR24 h ,and to highest point after 3 days.While PKC increased gradually after CIR6h ,and kept high level for 5 days.Conclusions Early Cell-derived brain edema may relate to the rise of PKC ;upper vasogenic brain edema may be related to the rise of AQP4.