摘要
目的研究电磁脉冲（electromagnetic pulse，EMP）辐照对大鼠血脑屏障通透性及血脑屏障紧密连接（tight junction，TJ）相关蛋白的影响。方法66只健康成年雄性SD大鼠按体重随机分为假辐照组和辐照组，EMP辐照参数为：场强200kV／m，脉宽7ns，脉冲次数200，脉冲重复频率1Hz。辐照后不同时间取材，用白蛋白免疫组织化学方法观察EMP辐照后血脑屏障通透性的变化，免疫印迹法检测脑组织和脑微血管中TJ蛋白（occludin和ZO—1）的表达情况，免疫荧光方法观察微血管紧密连接蛋白的分布情况。结果免疫组织化学结果显示，辐照后0．5h即可见有白蛋白漏出的微血管，但数目较少，随辐照后时间延长，有白蛋白漏出的微血管数目逐渐增加，至辐照后3h达到高峰，辐照后6h时开始恢复，辐照后12h基本恢复至对照水平；免疫印迹结果显示，occludin蛋白水平与对照组相比无明显差异；ZO-1蛋白水平在辐照后1、3h明显降低，并且免疫荧光结果显示ZO-1在微血管上的分布亦发生了改变，由辐照前的连续分布变为断续分布。结论EMP辐照后ZO-1蛋白水平和分布的改变可能是EMP致大鼠血脑屏障通透性增加的分子机制之一。
Objective To study the effect of electromagnetic pulse（EMP） on the permeability of blood-brain barrier, tight junction （TJ）-associated protein expression and localization in rats. Methods 66 male SD rats, weighing （200-250） g, were sham or whole-body exposed to EMP at 200 kV/m for 200 pulses. The repetition rate was 1 Hz. The permeability of the blood-brain barrier in rats was assessed by albumin immunohistochemistry. The expression of typical tight junction protein ZO-1 and occludin in both cerebral cortex homogenate and cerebral cortex microvessel homogenate was analyzed by the Western blotting and the distribution of ZO-1 and occludin was examined by immunofluorescence microscopy. Results In the sham exposure rats, no brain capillaries showed albumin leakage, at 0.5 h after 200 kV/m EMP exposure for 200 pulses; a few brain capillaries with extravasated serum albumin was found, with the time extended, the number of brain capillaries with extravasated serum albumin increased, and reached the peak at 3 h, then began to recover at 6 h. In addition, no change in the distribution of the occludin was found after EMP exposure. Total occludin expression had no significant change compared with the control. However, the expression level of ZO-1 significantly decreased at 1 h and 3 h after EMP exposure in both cerebral cortex homogenate and cerebral cortex microvessel homogenate. Furthermore, immunofluorescence studies also showed alterations in ZO-1 protein localization in cerebral cortex microvessel. Conclusion The EMP exposure （200 kV/m, 200 pulses） could increase blood-brain barrier permeability in rat, and this change is associated with specific alterations in tight junction protein ZO-1.
出处
《中华劳动卫生职业病杂志》
CAS
CSCD
北大核心
2009年第9期539-543,共5页
Chinese Journal of Industrial Hygiene and Occupational Diseases
基金
国家自然科学基金资助项目（30670492）
全国优秀博士学位论文作者专项基金（200465）
国家高技术研究发展计划（863）（2006AA0224C3）
关键词
辐射
电磁场
血脑屏障
蛋白类
Radiation
Electromagnetic fields
Blood-brain barrier
Connexins
