脑缺血大鼠水通道蛋白-9 mRNA表达与钙离子浓度的改变及其关系

Changes and their relationship of aquaporin-9 mRNA expression and Ca^(2+) concentration after cerebral ischemic in rats

目的研究脑缺血后脑组织水通道蛋白-9(AQP9)mRNA表达和Ca2+浓度的改变及其关系。方法制作脑缺血大鼠模型,在脑缺血6h、1d、2d、3d、5d,用半定量逆转录聚合酶链反应(RT-PCR)检测缺血脑组织AQP9mRNA的表达水平;用Fura-2/AM荧光法测定水肿区脑细胞内Ca2+浓度;并与对照组比较。结果与对照组相比,脑缺血后6h,水肿区脑组织AQP9mRNA表达水平和Ca2+浓度均开始增高,在脑缺血后第2d、3d表达最强(P<0.05～0.01);AQP9mRNA表达水平与Ca2+浓度呈正相关(r=0.7654,P<0.05)。结论脑缺血后AQP9表达增强,Ca2+浓度增高;提示AQP9和Ca2+可能共同参与缺血性脑水肿的形成。

Objective To investigate the changes and their relationship of aquaporin-9 （AQP9） mRNA expression and Ca^2＋ concentration of brain tissue after cerebral ischemic. Methods The models of cerebral ischemic in the rats were made by occluding unilateral middle cerebral artery with the suture method. The expression level of AQP9 mRNA was assessed by RT-PCR at interval times of 6 h, 1 d, 2 d, 3 d,5 d after cerebral ischemic, respectively. Fura-2/AM fluoremetry technique was used to determine the cellular Ca^2＋ concentration of brain tissue. The results were compared with control group. Results Compared with control group, the expression level of AQP9 mRNA and the concentrations of Ca^2＋ significantly increased at 6 h in ischemic edema tissue, and reached a peak at 2 d ,3 d after cerebral ischemic （ P 〈 0.05 - 0.01 ）. There was a positive correlation between expressions level of AQP9 mRNA and concentration of Ca^2＋ after cerebral ischemic （ r = 0. 7654, P 〈 0.05 ）. Conclusions Both the expression of AQP9 mRNA and concentration of Ca^2＋ in ischemic tissue increase after cerebral ischemic, which indicates that the AQP9 and Ca^2＋ may be significantly correlated with the ischemic edema formation.