微波辐射对小鼠胸腺作用的时间-效应关系  

Time-effect of microwave radiation on thymocytes in mice

作　　者：孙侠[1] 张文辉[1] 牛玉杰[1] 曾明[2] 侯玉春[2] 王秀荣[1] 

机构地区：[1]河北医科大学劳动卫生学教研室,河北石家庄050017 [2]河北医科大学组织胚胎学教研室

出　　处：《毒理学杂志》2005年第3期189-192,共4页Journal of Toxicology

摘　　要：目的探讨微波辐射对小鼠胸腺细胞作用的时间效应关系。方法取幼年小鼠,在微波频率2450MHz,功率密度5mWcm2条件下,1hd,连续辐射分别到3、9、15、21、30d时,断颈取出胸腺。测定小鼠胸腺指数,观察胸腺组织学变化,流式细胞术分析胸腺T细胞亚群、胸腺细胞凋亡率、胸腺细胞周期进程的变化情况。结果微波辐射后,辐射组小鼠体重在9、30d较对照组明显下降(P<0.05)。辐射9d后,辐射组小鼠胸腺重量较对照明显降低(P<0.05)。各时段辐射组胸腺系数与对照组相比,差异均无显著性(P>0.05)。镜下观察15d后各组胸腺组织,胸腺皮、髓质结合部,凋亡细胞略显增多。辐射15d后,实验鼠与对照鼠相比CD8标记率显著增高(P<0.05)。在辐射3d组,S期胸腺细胞百分比显著高于对照组(P<0.01),增殖指数(PI)在辐射9d组显著高于对照组(P<0.05)。15、30d辐射组胸腺细胞凋亡率较对照均有显著性(P<0.05)。不同辐射时段,小鼠胸腺细胞DNA含量和对照相比,差异均无显著性(P>0.05)。结论频率为2450MHz、5mWcm2的亚慢性微波辐射可诱导小鼠胸腺细胞凋亡,影响胸腺细胞周期进程,从而抑制小鼠免疫功能。Objective To investigate the time-effects of microwave radiation on thymocytes in mice. Methods Mice of childhood were whole-body exposed to microwave radiation with frequency of 2 450 MHz at power density of 5 mW/cm^2 respectively for 30 days 1 hour everyday. The experimental animals were decapitated at 3rd,9 th, 15 th,21 st,30 th day.The following parameters were measured：thymus index; typical morphological characteristics of thymus by HE staining observed under lighter microscope; the changes of thymocyte subgroups, the changes of cell cycle progression in thymocytes and the thymocytic cellular apoptosis detected with flow cytometry （ FCM）. Results The body weights were obviously lower than that of corresponding control at 9 th and 30 th day（ P 〈 0.05）. Body weight in every treatment group were not marked changes compared with false irradiation group （ P 〉 0.05）, expected 9 days of irradiation. Thymus index in every treatment group were not marked changes （ P 〉 0.05）. By pathological observation at 15 th, 21 th, 30 th day group,dark red piece of nucleus could be seen in the thymocytes, some cell core inclined to side, but hassall body showed to increase slightly; The expressions of CD8 increased obviously at 15 th days compared with control （ P 〈 0.05）. The number of S phase cells was obviously higher than that of control after 3 days expose （ P 〈 0.05）. PI was obviously higher than that of control at 9 th day irradiation（ P 〈 0.05）.The thymocytic apoptosis rates were significantly increased at 15 th day and 30 th day irradiation （P 〈 0.05）. The DNA content had no obvious difference in every irradiation group （ P 〉 0.05）. Conclusion microwave exposure with frequency of 2 450 MHz at power density 5 mW/cm^2 could induce thymocytes apoptosis, cause pathological changes in thymus, affect cell cycle progression in thymocytes, could influence the immune function through the damage of thymus and so on.

关 键 词：微波 免疫功能 胸腺 细胞劂朗 细胞凋亡 

分 类 号：R135.99[医药卫生—劳动卫生]