大鼠心肺复苏后脑组织含水量和水通道蛋白-4的动态变化及其相关性研究

目的 探讨复苏后缺血缺氧性脑病大鼠脑组织含水量（BWC）与水通道蛋白-4（aquaporin-4，AQP4）表达水平的动态变化及其相关性。方法 建立大鼠窒息心肺复苏模型，干湿质量法测定自主循环恢复后1、3和6hBWC的变化；同时，利用半定量免疫组织化学的方法检测脑组织AQP4表达水平的变化；分析两者的相关性。结果大鼠复苏后，随时间的延长BWC明显增加。各时间点BWC与对照组相比均有显著性差异（P值均〈0．05）。其中，复苏组大鼠6hBWC明显高于1、3h；而1、3h大鼠的BWC无明显差异。同时，复苏后脑组织AQP4水平的表达，也呈现出与BWC变化几乎相同的趋势。相关分析表明，BWC与脑组织AQP4呈明显正相关（r=0、791，P〈0.01）。结论 复苏后早期大鼠已出现明显的脑水肿，且与脑组织AQP4表达水平正相关，提示AQP4可能参与复苏后早期脑水肿的形成过程。

Dynamic change and correlation of brain water content with AQP4 expression level in the brain tissue after CPR in rats

Objective To study the dynamic change and the correlation of brain water content(BWC) with AQP4 expression level in hypoxia ischemic encephalopathy in rats after CPR.Methods The cardiac arrest model of rat was duplicated by asphyxy method.The BWC was measured by means of wet-to-dry weight ratio at 1,3 and 6 h after ROSC,and the AQP4 expression level in brain tissue was assessed by semi-quantization immuno-histochemistry staining at the same time.The correlation was analyzed(between) the BWC and AQP4 expression level.Results The BWC of rats increased obviously along with the prolongation of time following ROSC.The brain water contents at 1,3 and 6 h after ROSC were significantly higher than those of the control group(P<0.05).Moreover,the BWC at 6h after ROSC was much higher than those at 1 and 3 h after ROSC;and there was no significant difference in the BWC between the groups at 1 h and 3 h after ROSC.At the same time,the change of AQP4 expression level in brain tissue was as nearly same as that of the BWC.The correlation analysis demonstrated further that the BWC was correlated apparently with the AQP4 expression level in brain tissue(r=0.791,P=0.000).Conclusion The brain edema has formed obviously in the early stage after ROSC,and it is positively correlated with the AQP4 expression level in brain tissue,indicating that AQP4 participates probably in the development of brain edema.