X波段微波辐照致心肌损伤及机理研究

 采用90 W/cm² X波段微波全身一次辐照大鼠10 min，分别于辐照后0，0.5，1，3，6，12，24 h断头处死，取左心室心肌组织，光镜观察心肌组织形态学损伤；TUNEL法检测心肌组织细胞凋亡；RT-PCR检测大鼠心肌组织GSK3β，caspase-9和caspase-3 mRNA表达水平的变化；Western-blot法检测大鼠心肌组织GSK3β蛋白质磷酸化表达水平的变化；Caspase-9分析试剂盒检测心肌组织中caspase-9酶活性。研究结果表明：90 W/cm² X波段微波辐照可上调心肌组织GSK3β基因表达，使其蛋白磷酸化水平降低，解除了磷酸化对其活性的抑制，使GSK3β活性增强，从而参与了X波段微波辐照致心肌细胞凋亡的启动。90 W/cm² X波段微波辐照同时可使大鼠心肌组织中的凋亡相关蛋白激酶caspase-9和caspase-3基因表达上调，caspase-9酶活性增强，从而造成大鼠心肌细胞凋亡过程的启动，因此，GSK-3β及其下游介导的与凋亡相关的信号分子caspase-9和caspase-3的激活可能是X波段微波辐照致大鼠心肌细胞凋亡的重要途径之一。

Cardic injury induced by X-band microwave irradiation in rats and its mechanism

Wistar rats were exposed to 90W/cm2 X-band HPM irradiation for 10 minutes. Myocardial tissues were collected at 0, 0.5, 1, 3, 6, 12, 24 h post exposure. The histopathological changes were observed with light microscope. The cardiomyocytes apoptosis were determined by TUNEL method. The changes of GSK-3β, caspase-9 and caspase-3 mRNA expression in rat myocardium after 90 W/cm2 HPM irradiation were determined by using RT-PCR. The changes of GSK-3β phosphorylation were determined by using western blotting. The changes of caspase-9 enzymes activity induced by HPM irradiation were assessed via a colorimetric assay utilizing specific substrates. X-band microwave irradiation can induce cardiomyocyte apoptosis. HPM also leads to obvious activation of GSK3β and coupled signal transduction pathway