3种波段电磁辐射致大鼠脾脏损伤的定量比较研究

目的比较3种不同波段电磁波全身照射后脾脏损伤病理变化的差异。方法分别采用电磁脉冲（EMP）、S波段高功率微波（S-HPM）和X波段高功率微波（X-HPM）全身照射Wistar大鼠120只，并设伪照射40只为对照组。分别于辐照后6h、1d、3d、7d、14d、28d、6m、12m分批麻醉活杀，取脾脏组织，分别制作石蜡切片和超薄切片，进行组织学和超微结构观察；根据淋巴细胞凋亡数、增生程度、脾小体萎缩程度和间质纤维组织增生程度对辐射损伤的生物学效应进行定量检测和分级。结果电镜下在不同时期均可观察到凋亡和坏死图象。光镜下：三个实验组大鼠辐照后脾脏发生相似的损伤效应，即早期以淋巴细胞凋亡为主，伴随脾小体不同程度的萎缩，中晚期淋巴细胞开始增生和间质以纤维组织增生为主；病变经历平台期、高峰期和修复期，各期出现的时间、平台期持续时间以及损伤程度均存在组间差异：上述变化均以X-HPM组和S-HPM组重于和早于EMP组，尤其以X-HPM组最为明显。结论3种不同波段电磁波均可导致脾脏基本相似的时相性辐射效应，表现为淋巴细胞凋亡、脾小体萎缩、淋巴细胞增生和间质纤维组织增生，所致效应的程度及其时相性变化因辐射源的种类和频率的不同而各有其特点。

Comparison of splenic damages induced by three frequency microwave in rats

Objective To investigate the differences of radiation damage to rat spleen resulted from three-frequency microwaves： EMP, S-HPM and X-HPM. Methods Rats were irradiated by three-frequency microwaves, EMP, S-HPM and X-HPM, respectively. The spleen tissue samples were collected at 6 h, 1 d, 3 d, 7 d, 14 d, 28 d, 6 m and 12 m after irradiation. Part of them were used for routine histopathological examination. Another part of them were fixed in2.5% glularaldehyde and prepared for electron microscopic observation. The radiation damages were classified according to the degree of apoptosis, lymphocyte proliferation, atrophy of splenic nodules and interstitial fibrosis. Results Apoptosis in lymphocytes was identified under the electron microscope at all time points after irradiation. The morphological radiation damages responded to EMP, S-HMP and X-HMP were similar with each other observed by light mi-croscopy. The processes of response to the microwave radiation were classified into three stages--early, intermediate and late stages, according to the time course, and there were plateau stage, peak stage and recovery stage according to the degree of splenic damages. Apoptosis occurred mainly in the early stage, and accompanied by atrophy of splenic nuodules. Lymphocyte proliferation and interstitial fibrosis started to show in the intermediate to late stage, and interstitial fibrosis became severe in the late stage. There were differences between the experimental groups and control group regarding the time of occurrence of plateau stage and peak stage, the duration of each stage, and the degree of radiation damage. Conclusion i The radiation damages to rat spleen induced by the three frequency microwaves are similar. The major morphological changes are lymphocyte apoptosis, lumphocyte proliferation, atrophy of splenic nodules and interstitial fibrosis, which are characteristic according to the type and frequency of microwaves.