水通道蛋白-4在大鼠创伤性脑水肿中的表达及其意义

目的探讨水通道蛋白-4(AQP4)在大鼠创伤性脑水肿形成过程中的表达变化及其意义。方法选择健康成年Wistar大鼠随机分为实验组(n=60)和对照组(n=15),实验组采用改进的Feeney氏法,造成大鼠右侧大脑半球局部脑损伤;对照组仅切开头皮,不造成大鼠脑损伤。分别进行脑组织形态学观察、脑含水量检测、免疫组织化学方法检测各组AQP4的表达水平。结果实验组72h病灶区域脑组织含水量百分率(80.18±0.55)%较对照组(78.10±0.52)%]高(P<0.05)。实验组1、3h AQP4平均吸光度值(0.210 0±0.029 4、0.186 0±0.016 5)较对照组(0.143 3±0.053 8)高(P<0.05)。结论在脑创伤早期,AQP4强烈表达,可能与脑创伤后的应激反应有关。在脑创伤后期,由于AQP4表达呈下调趋势,其活性降低,出现混合性脑水肿。

Expression and its significance of aquaporin-4 in rat brain injury model

Objective To investigate the changes of aquaporin-4(AQP4)expression after traumatic brain injury(TBI)in rats and its correlation with cerebral edema.Methods Healthy Wistar rats were randomly divided into the control group(n=15)and the experimental group(n=60).The experimental group adopted the improved Feeney method for establishing local TBI model of right cerebral hemisphere.The control group received the scalp incision without cerebral injury.The morphological observation of cerebral tissues and the brain water content(BWC)determination were performed.AQP4 expression was detected by the immunohistochemistry(IHC)method.Results The percentage of BWC in cerebral injury area at 72 h in the experimental group was(80.18±0.55)%],which was higher than(78.10±0.52)%] in the control group(P<0.05).The average absorbance value at 1,3 h in the experimental group were(0.210 0±0.029 4),(0.186 0±0.016 5),which were higher than(0.143 3±0.053 8)in the control group(P<0.05).Conclusion At the earlier stage of TBI,the expression of AQP4 is strongly increased,which may be related with the stress reaction after TBI.At the later stage of TBI,the expression of AQP4 is down-regulated and its activity is reduced,resulting in mixed cerebral edema.