高功率微波辐射后大鼠海马组织中突触后致密物-95及cAMP反应元件结合蛋白的变化

Changes in expressions of PSD-95 and CREB in hippocampi of rats after exposure to high power microwave

目的观察高功率微波（HPM）辐射后大鼠海马组织中突触后致密物（PSD）-95及cAMP反应元件结合蛋白（CREB）的变化。方法采用10、30和100mW／cm^2HPM照射75只Wistar雄性大鼠，于辐射后6h、1、7、14和28d活杀取海马组织，采用免疫组化、凝胶阻滞实验和图像分析等技术，观察海马神经元中PSD-95及CREB的变化。结果HPM辐射后大鼠海马神经元胞浆中PSD-95的表达有不同程度的增加；10mW／cm^2组辐射后6h，PSD-95表达增加，于辐射后1d达高峰，28d基本恢复正常；100mW／cm^2组辐射后6h，PSD-95表达增加，MOD于1d达高峰，IOD于7d达高峰，28d基本恢复至正常水平；30mW／cm^2组于辐射后3d内，海马组织CREB与DNA的结合能力进行性降低。结论HPM辐射后大鼠海马PSD-95表达增加，CREB与DNA结合能力减弱，参与了HPM辐射后海马组织损伤及海马神经元突触可塑性改变的病理生理过程。

Objective investigate the change of the expressions of PSD-95 and CREB in hippocampi of rats after exposure to high power microwave （ HPM）. Methods The HPM device with mean power densities of 10, 30 and 100 mW/cm^2 was used to expose 75 healthy Wistar male rats, which were killed on at hour 6, days 1, 7, 14 and 28 after irradiation. The expressions of PSD-95 and CREB were analyzed by immunohistochemistry, gel retardation assay and imaging analysis. Results The expression of PSD-95 in hippoeampi of rats was up-regulated after 10 and 100 mW/cm^2 exposure. The levels of PSD-95 in hippocampi rised at hour 6 after exposure to 10 mW/cm^2 , peaked at day 1, and returned to the basal level at day 28 after exposure. The levels of PSD-95 went up at hour 6 after 100 mW/cm^2 exposure, peaked at day 1 （MOD） and 7 （IOD） respectively, and returned to the basal level at day 28 after 100 mW/cm2 exposure. The binding ability of CREB and DNA was declined within 3 d after exposure to 30 mW/cm^2 HPM. Conclusions The levels of PSD- 95 in hippocampi are increased, but the binding ability of CREB and DNA declined after exposure to HPM, which is contributed to the patho-physiological process of hippocampus tissue injury.