The difference in the radiosensitivity between hematopoietic stem and progenitor cells after different doses of 137Csγ-radiation / 天津医药

ABSTRACT

Objective To observe the different radiosensitivity induced by different doses of 137Csγ-ray irradiation between hematopoietic stem and progenitor cells. Methods Seventy-two C57BL/6 mice were randomly divided into control group and irradiated groups (2, 4 and 6 Csγ-ray irradiation, n=18 for each group). Mice of control group received sham irradiation, and the rest accepted 2, 4 and 6 Gy137Csγtotal body irradiation, respectively. After 14-day, 35-day and 56-day irradiation, the peripheral blood samples were collected by balls enucleation. The number of bone marrow nuclear cells, hematopoietic stem and progenitor cells were counted. Results The peripheral blood of irradiated mice showed significant changes in the number of white blood cells (WBC), red blood cells (RBC), platelets (PLT) and hemoglobin (HGB) in a dose-response relationship. Compared with the control group, the numbers of BMNCs and hematopoietic progenitor cells (HPCs) were significantly lower in irradiated group. At 35 d and 56 d after 6 Gy irradiation the numbers of BMNCs and HPCs were significantly lower than those of control group (P<0.05). There were no significant differences in numbers of BMNCs and HPCs between irradiated groups (2 and 4 Gy) and control group. The number of bone marrow hematopoietic stem cells (HSCs) was significantly lower in irradiated group than that in control group after 14-d and 56-d irradiation (P<0.05). Conclusion 137Csγ-ray irradiation has some damage in mouse hematopoietic system. The damage caused by radiation is persistent to hematopoietic stem cells.