微波辐射后大鼠海马组织中水通道蛋白4的表达

A aquaporin 4 expression and effects in rat hippocampus after microwave radiation

目的探讨微波辐射后大鼠海马组织中水通道蛋白4（AQP4）的表达。方法采用0、10、30和100mW／cm^2微波辐射70只雄性Wistar大鼠，于辐射后6h及1、3、7、14d活杀大鼠取海马，采用免疫组化和Westernblot方法检测大鼠海马组织中AQP4蛋白表达的变化，原位杂交、反转录-聚合酶链反应（RT-PCR）观察AQP4基因水平的改变。结果10、30、100mW／cm^2微波辐射后大鼠海马组织中AQP4表达异常，其蛋白水平于10、30mW／cm^2组呈先增加后恢复的过程，100mW／cm^2组则呈进行性增加改变，与假辐射组比较，差异有统计学意义（P〈0．01）。10mW／cm^2组于辐射后6h AQP4 mRNA即升高（0．51±0．02），与对照组比较，差异有统计学意义（P〈0．01）；30、100mW／cm^2组均在7d时达最大值（分别为0．46±0．02、0．43±0．08），与对照组比较，差异有统计学意义（P〈0．01，P〈0．05）。结论微波辐射可导致大鼠海马组织中AQP4表达增加，此改变有可能参与了微波辐射致血脑屏障通透性升高的过程及脑水肿的发生。

Objective To investigate the expression of aquaporin 4 （AQP4） after microwave exposure and the correlation with the brain injury by radiation. Methods 70 male rats were exposed to microwave whose average power density was 0, 10, 30 and 100 mW/cm^2 respectively. Rats were sacrificed at 6 h, 1 d, 3 d and 7 d after exposure. Immunohistnchemistry and Western blot were used to detect the expression of AQP4 in protein level in rat hippocampus, and the expression of AQP4 in gene level was measured by in situ hybridization and RT-PCR. Results The expression of AQP4 in rat hippocampus was abnormnal after 10, 30, 100 mW/cm^2 microwave exposure. The protein level showed increased at first and then recovered at 10 and 30 mW/cm^2 groups, while increased progressively in 100 mW/cm^2 group within 14 d（P〈0.01）. The gene expression of AQP4 was increased （0.51 ±0.02） at the beginning （6 h） and then regained after 10 mW/cm^2 microwave exposure, while in 30 and 100 mW/cm^2 groups, it rose to the peak at 7 d （0.46±0.02 and 0.43±0.08） and didn＇t get back （P=0.004;P=0.012）. Conclusion Microwave radiation can increase the expression of AQP4 in rat hippocampus. The change might participate in the process of increasing permeability of blood-brain barrier and lead to the brain edema after microwave radiation.