不同强度微波辐射对小鼠胸腺的影响

Effects of microwave radiation on thymocytes in mice at different power densities

目的 探讨不同强度微波辐射对小鼠胸腺细胞的影响。方法 取幼年小鼠 ,分别在微波频率 2 4 5 0MHz,功率密度 1、5、15mW cm2 条件下 ,每天辐射 1h ,连续全身辐射 30d后 ,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 5、15mW cm2 辐射组体重分别为 (2 8.10± 1.4 6 )、(2 7.5 0± 2 .5 2 )g,与对照组 [(31.95± 2 .5 1)g]相比 ,差异均有显著性 (P <0 .0 5 ) ;病理观察发现 ,中、高强度辐射组小鼠胸腺实质细胞可见深染核碎块 ,有些细胞核偏向一侧 ,胸腺小体略显增多 ;中、高强度辐射组胸腺细胞亚群CD8标记率 (2 9.14 %± 1.6 8%、2 9.18%± 0 .81% )比对照组 (2 6 .95 %± 1.2 7% )明显增高 ,差异有显著性 (P <0 .0 5 ) ;中、高强度微波辐射导致胸腺细胞周期进程中G2 +M期细胞百分比 (12 .2 4 %±1.82 %、11.19%± 1.36 % )较对照组 (14 .5 8%± 0 .6 4 % )降低 ,且差异有显著性 (P <0 .0 1) ;3个辐射组胸腺细胞凋亡率分别为 7.18%± 0 .99%、10 .0 6 %± 1.5 8%、9.4 5 %± 0 .92 % ,与对照组 (4 .2 5 %±1.6 3% )相比 ,均有明显增加 ,差异有显著性 (P <0 .0 1) ,但 5、15mW cm2 两组间差异无显著性 (P >

Objective To investigate the effects of microwave radiation on thymocytes in mice at different power densities. Methods The experimental animals were whole-body exposed to microwave radiation with frequency of 2 450 MHz,power density of 1,5,15 mW/cm2 respectively 1 h everyday for 30 days.Then the thymus were taken out after the mice were decapitated.Thymus index,morphological characteristics of thymus were examined.The changes of thymus T-cell subgroups,cell cycle progression in thymocytes and cellular apoptosis were detected with flow cytometry(FCM). Results The body weights of animals in 5,15 mW/cm2 irradiation groups [(28.10±1.46),(27.50±2.52)g] were lower than that of the control[(31.95±2.51)g](P<0.05).Pathological observation showed dark red piece of nucleus,some nuclei inclined to one side,slight increase in hassall body.The expressions of CD8 in 5,15 mW/cm2 irradiation groups(29.14%±1.68%,29.18%±0.81%) were higher than that in control group(26.95%±1.27%)(P<0.05).The percentages of G 2+M phase thymocytes in both radiation groups(12.24%±1.82%,11.19%±1.36%) were lower than that in control group(14.58%± 0.64%)(P<0.01).Thymocytic apoptosis rates in the three experimental groups(7.18%±0.99%,10.06%±1.58%,9.45%±0.92%) were higher than that in control(4.25%±1.63%)(P<0.01),but the evident difference between 5 mW/cm2 and 15 mW/cm2 was not found(P>0.05). Conclusion Sub-chronic microwave exposure (2 450 MHz,5,15 mW/cm2) could induce thymocyte apoptosis,cause pathological changes in thymus,and affect cell cycle progression,thus may inhibit the immune function of the animal.