微波辐射对大鼠血脑屏障通透性影响

Effects of microwave radiation on permeability changes of blood-brain barrier in rats

目的研究微波辐射对大鼠血脑屏障（BBB）结构与功能的影响。方法采用10.30和100mW/cm^2微波辐射Wistar大鼠,通过苏木素伊红（HE）染色观察BBB形态结构的变化;采用伊文思蓝（EB）染色和硝酸镧电镜示踪检测BBB通透性变化。结果10～100mW/cm^2微波辐射后大鼠大脑皮层与海马部分胶质细胞固缩深染;血管周间隙增宽。假辐射组EB局限于血管腔内;100mW/cm^2组辐射后3d,可见EB弥散至血管腔外。定量分析结果可见,10～100mW/cm^2微波辐射后3～14 d海马组织中EB含量均高于假辐射组,其中10和30mW/cm^2组在7 d内进行性增加,14 d恢复;100mW/cm^2组在14 d内进行性增加。假辐射组镧离子仅滞留在血管腔内;100mW/cm^2组辐射后1和7 d,镧颗粒分别见于血管周围的内皮下层及脑间质细胞间隙。结论微波辐射可致大鼠BBB结构与功能发生改变,BBB通透性增加。

Objective To study the influence of microwave radiation on the structure and function of blood- brain barrier（BBB） in rats. Methods Wistar rats were exposed to microwaves with average power densities of 10, 30 and 100mW/cm^2 respectively. Hematoxylin eosin（HE） staining was used to observe the changes of morphology in BBB. Evans blue（EB） dye and lanthanum nitrate were used to test the permeability of BBB. Results After being exposed to 10 - 100mW/cm^2 microwave, parts of gliocyte showed pyknosis and anachromasis in cerebral cortex and hippocampus. The perivascular space widened. In sham - group, the red fluorescence of EB was limited in lumens of blood vessels, while it dispersed out of the blood vessels at 3d in 100mW/cm^2 group. There was an increase of EB contents in hippocampus in 3 - 14 d after 10- 100mW/cm^2 microwave radiation. The EB content increased progressively in 10 and 30 mW/cm^2 groups within 7d and recovered at 14d, while it increased progressively in 100mW/cm2 group within 14d. Lanthanum ions were in the blood vessel in sham - group ; and they were observed in circumvascular subendothelial layer at 3d and in extracellular space of brain dintersfitial cells at 7d in 100 mW/cm^2 group. Conclusion Microwave radiation can damage BBB structure and function and result in the increase of permeability of BBB.