Abstract:

Objective To dynamically observe the morphological changes of bone marrow of mouse bone marrow depression and regeneration model. Methods Mouse bone marrow depression and regeneration model was established by injection of 250 mg/kg 5-fluorouracil (5-Fu) via tail vein. Blood samples were taken before 5-Fu injection (control group, n=6) and 3 d, 7 d, 11 d and 14 d after 5-Fu injection (model 3 d group, model 7 d group, model 11 d group and model 14 d group, respectively, n=6), bone marrow samples were obtained after sacrifice of mice, and bone marrow paraffin sections were then prepared with HE staining. The morphological changes of bone marrow during bone marrow depression and regeneration were dynamically observed. Results Femur bone marrow cavity was saturated with large number of erythrocytes and mononuclear cells, and was sparsely decorated with megakaryocytes. The numbers of erythrocytes, mononuclear cells and megakaryocytes dramatically decreased in model 3 d group, and to a nadir in model 7 d group. Subsequently, bone marrow regeneration initiated, and repopulated cells formed a characteristically dynamic distribution in model 11 d group, with assembly of erythrocytes in lower part of femur and assembly of mononuclear cells and megakaryocytes in middle and upper part of femur, respectively. This distinguished feature began to disappear in model 14 d group. Conclusion There exist a characteristic cell assembly and disassembly process during mouse bone marrow depression and regeneration induced by 5-Fu.

Key words: 5-fluorouracil, bone marrow, depression, regeneration, morphology