小鼠低剂量辐射损伤模型的初步研究

目的:对小鼠低剂量辐射损伤模型进行初步研究并筛选敏感检测指标.方法:实验分7组,1组为正常组,其余6组用XHA600直线加速器射线照射,每组取一部分小鼠于照射后2、4、8、16h测定红细胞(RBC)、白细胞(WBC)、血小板(PLT)和血红蛋白(HGB)含量；测定小鼠肝脏和脾脏重量及其组织中的超氧化合物歧化酶(SOD)和丙二醛(MDA)含量；剩余小鼠于4周后观察骨髓切片中血细胞变化.结果:照射后4h测定血常规,发现累积辐射0.4Gy组小鼠RBC有降低趋势,WBC、HGB显著降低,PLT显著升高；肝脏、脾脏的湿质量显著降低；小鼠肝脏组织中MDA的含量显著升高、SOD的活力显著降低；4周后小鼠骨髓细胞的病理改变与单次照射剂量相关,单次较大剂量(如0.6Gy)照射对骨髓细胞影响较大,在4周观察期不能自身恢复,而多次累积照射对骨髓细胞病理改变较小.结论:小鼠低剂量辐射损伤模型的最佳造模剂量为累积照射0.4Gy即每次照射100mGy,间隔一天,连续照射4次.

Research of the Model of Low Dose Radiation-injured Mice

Objective: To study low dose radiation-injured mice model and select sensitive indexe.Methods: The mice were divided into seven groups,one was the control group and the rest six groups irradiated by XHA600 linear accelerator were experimental groups.2,4,8,16hours after the irradiation,part of experimental groups were measured to test the content of blood cells,such as red blood cells(RBC),white blood cells(WBC),platelets(PLT) and hemoglobins(HGB).The weight of liver,spleen and superoxide dismutase(SOD),maleic dialdehyde(MDA) in the organs of these groups had been measured too.The bone marrow biopsy of remaining mice were observed after four weeks.Results: The group exposed in radiation(cumulative dose of 0.4 Gy) had significant decrease in the content of WBC and HGB;the content of RBC decreased too.On the contrary,the content of PLT in this group increased significantly;the weight of liver and spleen in this group decreased significantly;MDA content in liver tissue increased significantly;SOD activity in liver decreased significantly.After 4 weeks,the pathological changes of mice bone marrow cells were associated with the amount of single dosage.What’s more,a large single dose(eg,0.6Gy) radiation had greater impact on bone marrow cells,and those cells could not restore themselves during the observation period(4 weeks),however,the cumulative groups had little pathological changes in bone marrow cells.Conclusion: The best low dose radiation-injured mice model is 0.4Gy of cumulative radiation dose group.