不同剂量X线照射对小鼠细胞免疫功能的影响

Influence of different doses of X ray irradiation on cell-mediated immunity of BALB/C mouse

目的研究不同剂量X线照射对小鼠细胞免疫功能的影响。方法:75只8～10周龄BALB/C小鼠随机分为3组:A、B组分别应用直线加速器分别经2Gy和3Gy照射(X线),C组为正常对照组,不接受照射。流式细胞仪测定第1～5周各组动物外周血T细胞亚群(CD_3^+、CD_4^+、CD_8^+)及NK细胞(CD_(16)^+CD_(56)^+)的变化,并对脾及胸腺变化作病理学观察。结果:经照射的小鼠,其外周血T细胞亚群及NK细胞呈进行性降低,至第3、4周开始出现逐渐恢复迹象,4、5周后恢复正常。在同一时间,3 Gy照射较2 Gy照射所导致的细胞亚群降低的程度更为明显(P<0.05)。脾、胸腺在照射后重量减轻并延续至4周才基本恢复至照射前的水平。观察5周各组未出现自然死亡。结论:BALB/C小鼠经照射后细胞免疫功能下降明显,4～5周后免疫功能恢复。

Objective：To explore the influence of irradiation with different dose of X ray to cell-mediated immunity of BALB/C mouse. Methods： Seventy-five BALB/C mice aged 8--10 weeks were randomly divided into three groups： in group A and B, rats were respectively irradiated with linear accelerator for a dose of 2 Gy or 3 Gy, rats in group C served as normal controls. T cell subsets （CD3 ＋ , CD4 ＋ , CD8 ＋ ） and NK cell（CD18 ＋ CD56 ＋ ）of peripheral blood were examined with FACS Calibar, and pathological changes in spleen and thymus were observed. The observation time was 5 weeks. Results：The T cell subsets and NK cell in peripheral blood decreased progressively up to third and fourth week, and they began to recover gradually, approaching normal 4 and 5 weeks after irradiation. At the same time point, the extent of decrease in cell subsets in mice was more notable in mice receiving 3 Cry than that with 2 Cry （P〈0. 05）. After irradiation, the weight of spleen and thymus was decreased compared with normal mice, and 4 weeks later it recovered to the weight of before irradiation. No natural death was observed in mice receiving irradiation during 5 weeks. Conclusion.. The cell-mediated immunity of BALB/C mouse may be depressed obviously after irradiation with low dose of X ray irradiation, and it recovered gradually after 4-5 weeks. Key words