低剂量辐射对荷瘤小鼠抑瘤作用及其免疫功能的影响

EFFECTS OF LOW DOSE RADIATION ON TUMOR INHIBITION AND IMMUNOLOGICAL FUNCTION IN TUMOR-BEARING MICE

利用低剂量辐射（LDR）对接种Lewis肺癌细胞小鼠进行全身照射，观察了20d内肿瘤抑制率及免疫学指标的动态变化。研究结果表明，受75mGy剂量单次或分割照射后的肿瘤抑制率分别为40．34％和51．19％；脾NK细胞活性在照后1～4d呈一过性升高；外周血T淋巴细胞表面CD4、CD8水平早期不同程度增高；而CD4／CD8比值在照后也反映出升高。提示在本实验条件下，LDR对Lewis肺癌的生长有抑制作用，同时对荷瘤机体的免疫功能也显示一定的刺激效应。

This paper reports the effect of total body irradiation with low dose radiation (LDR) on tumor inhibition and the dynamic changes of immunological indexes in Lewis lung cancer cell-inoculated mice in 20days. Results show that tumor inhibitory rates in single and fractionated irradiation of 75mGy were 40% and 51% respectively, splenic NK cell activity was elevated in 1 to 4 days, CD4 and CD8 levels on T lymphocyte surface were up-regulated early to some extent, and the ratio of CD4/CD8 was risen post-irradiation. It suggests that under the experimental condition LDR might lead to growth inhibition of Lewis lung cancer cells and immunological hormesis in the tumor-bearing mice.