微波辐射对大鼠海马VEGF及其受体FLK-1表达的影响研究

目的探讨低剂量微波长期辐射后,大鼠海马组织中VEGF及其受体FLK-1表达变化及其与血脑屏障通透性改变的关系。方法采用2.5、5和10 mW/cm2微波辐射160只二级雄性Wistar大鼠,于辐射后6 h、7 d、14 d、1 m、2 m和6 m活杀取大鼠海马,通过免疫组织化学和图像分析等技术,检测VEGF及其受体FLK-1表达改变。结果假辐射组VEGF和FLK-1于神经元胞浆呈弱阳性。2.5、5和10 mW/cm2微波辐射后7 d~2 m,VEGF和FLK-1在大鼠海马毛细血管壁和神经元胞浆呈强阳性。2.5、5和10 mW/cm2组辐射后7 d,VEGF、FLK-1表达始见升高（P〈0.01）,于1 m内呈进行性增加改变（P〈0.01）,2 m有所下降,6 m见恢复。结论2.5~10 mW/cm2微波长期辐射可导致大鼠海马组织中VEGF及其受体FLK-1表达增加,可能参与了微波辐射致血脑屏障通透性升高的病理过程。

Effects of microwave exposure on VEGF and FLK-1 of hippocampus in the rats

Objective To investigate the changes of VEGF and FLK-1 expressions in rat hippocampus after a long-term exposure to low dose of microwave irradiation,and their correlation with the changes of blood-brain barrier（BBB） permeability.Methods One hundred and sixty male Wistar rats were exposed to 2.5,5 and 10 mW/cm2 microwave,once for 6 min,5 times per week,for a month.The rats were sacrificed of at 6 h,7 d,14 d,1 m and 2 m after the exposure,and the hippocampus tissues were taken out for immunohistochemical and image analysis and to detect the protein expression of VEGF and FLK-1 in the rat hippocampus.Results In the sham-group,VEGF and FLK-1 were presented weakly positive in the kytoplasm of hippocampal neurons,while at 7 d to 2 m,strong positive in the capillary wall and neuron kytoplasm after 2.5,5 and 10 mW/cm2 microwave exposure.The increased expression of VEGF and FLK-1 was found at 7 d（P0.01） after 2.5 to 10 mW/cm2 exposure,then increased progressively within 1 m（P0.01）,and there was a light decline at 2 m,and recovered at 6 m.Conclusions The expression of VEGF and FLK-1 was increased after 2.5 to10 mW/cm2 exposure,which might be participate in the process of increasing permeability of blood-brain barrier after microwave exposure.