肝硬化大鼠脑水通道蛋白-4、胶质纤维酸性蛋白表达与脑水肿关系

Relation of aquaporin_4,GFAP with brain edema in liver cirrhosis rats

目的观察肝硬化大鼠脑组织中AQP4和GFAP的表达并探讨其和脑水肿发生的关系。方法硫代乙酰胺法建立肝硬化大鼠模型;脑MRDWI扫描,测定DWI、ADC值;检测动脉血氨水平;免疫组化图像分析脑组织中AQP4、GFAP表达水平:观察大脑星形胶质细胞形态、血脑屏障超微结构变化。结果成功建立肝硬化大鼠模型;对照组MRIDWI扫描在感兴趣区域信号无差异(P>0.05);肝硬化组和对照组间动脉血氨水平无差异(P>0.05);肝硬化组大鼠脑组织中AQP4、GFAP表达增高(P<0.05)。病理观察发现血管周围间隙增加,电镜下见轻微脑星形胶质细胞水肿,血脑屏障无改变。结论肝硬化大鼠脑组织中AQP4、GFAP表达上调并伴有隐性的细胞水肿,GFAP表达增加和正常的血氨水平可能减轻AQP4对脑水肿发生的影响。

Objective To observe expression of aquaporin-4 （AQP-4） and GFAP in brain of experimental liver cirrhosis rats. Explore the mechanism of brain edema in liver cirrhosis rats. Methods Twenty male Sprague-Dawley rats were divided into two groups randomly, liver cirrhosis group （n = 10） and control group （n = 10）. Liver cirrhosis models were established by intraperitoneal injection of 10% solution of thioacetamide （TAA）, Using dosage of 150mg· kg^- 1, three times each week （first time 200mg· kg^-1） for 14 weeks. Brain MRI scan and value of DWI, arterial plasma ammonia, hematoxylin-eosin （HE） staining and transmission electron microscope were used. Results Liver cirrhosis models were made successfully. Compared with control group the level of arterial plasma ammonia and DWI signals had no difference in the partial area of regions of interest. Expression of AQP-4 and GFAP＇were up - regulated （ P 〈 0.05） ,and latent brain edema was observed by electron microscope in experiment groups. Conclusion Expression levels of AQP-4 and GFAP are up-regulated in group of liver cirrhosis rats accompanied low-grade brain edema. Up-regulated expression of GFAP and normal arterial plasma ammonia could attenuate the effect of AQP-4 which can facilitate brain edema potentially.