电磁脉冲辐射后小鼠免疫器官损伤的病理研究

目的 :研究电磁脉冲 (EMP)照射后小鼠脾脏和胸腺的组织病理变化。方法 :198只小鼠经 6× 10 4V/m电磁脉冲辐照后 6h、1d、3d、7d、14d、2 8d、3个月、6个月、9个月和 12个月共 10个时相点活杀取脾脏和胸腺 ,分别应用光镜和电镜进行组织学和超微结构观察。结果 :电磁脉冲辐照后早期 :脾脏脾小体结构不清 ,体积缩小 ,生发中心不明显 ;淋巴细胞核固缩、崩解 ;红髓中巨噬细胞增多 ,血窦扩张、充血明显。照后中期 :脾脏红髓纤维化 ;胸腺皮质细胞变性坏死 ,髓质内可见灶状出血 ,出血灶周围细胞核固缩。照后后期 :脾脏出现“假小叶”状纤维化 ,胸腺皮质变薄 ,髓质变宽 ,皮髓质比例倒置 ,髓质内纤维组织增生甚至纤维化。照后晚期 :脾脏被膜增厚 ,胸腺出现萎缩 ,脾脏和胸腺中的淋巴细胞均有所恢复。在透射电镜下 ,脾脏和胸腺内淋巴细胞均出现典型的凋亡图像。结论 :电磁脉冲辐照后脾脏和胸腺发生明显损伤 ,脾脏损伤更为严重和迅速 ,其病变具有进行性、阶段性及缓慢恢复性特点 ,表明免疫系统器官为EMP辐照敏感组织之一。

Pathological changes of immune organs in mouse after electromagnetic pulse irradiation

Objective: To study the histopathological changes of spleen and thymus in mouse after irradiation with EMP. Methods:The histopathological changes in routine paraffin section examined under light microscope and ultrastructural changes under TEM were observed. Results: In early stage after irradiation,the structure of splenic corpuscles was indistinct .The germinal center of splenic corpuscles also was at no longer distinguishable .The nuclei of lymphocytes were pyknotic and disintegrated, macrophages increased, sinusoid expanded and congestion was obvious in the red pulp.In middle stage, fibrosis of red pulp was found. The lymphocytes of thymus cortex showed degeneration and necrosis. Focal hemorrhage was seen in medulla and the surrounding cells were pyknotic. In late stage,the cortex of thymus became thin and medulla became wide and fibrotic. There were typical apoptosis in ultrathin sections of spleen and thymus.Conclusion: EMP can damage the spleen and thymus obviously, the lesion in spleen is more severe and rapid than that in thymus. The lesions of both organs have their regularity and can recover subsequently. These results indicate that the organs of immune system are sensitive to EMP radiation.