Effect of the administration time of hs6101 on hematopoietic recovery in ICR mice injured by cyclophosphamide / 解放军医学杂志

ABSTRACT

Objective To explore the effect of the administration time of HS6101 on hematopoietic recovery in ICR mice injured by cyclophosphamide (CTX). Methods One hundred and three male ICR mice were divided into 4 groups CTX control, HS6101 prevention, HS6101 treatment, and HS6101 prevention+treatment groups. CTX was intraperitoneally injected into the ICR mice at a dose of 100mg/(kg.d) for three consecutive days to establish a chemotherapeutics-injured model. HS6101 at a dose of 27μg/mouse in 0.2ml was subcutaneously injected into the mice 1h before the first administration of CTX in HS6101-preventiongroup, 1h after the last administration of CTX in HS6101 treatment group, and both at 1h before the first administration and 1h after the last administration of CTX in HS6101 prevention + treatment group. Physiological saline was subcutaneously injected into the mice in CTX control group (0.2ml/mouse). 10μl peripheral blood was collected from the caudal vein for WBC, neutrophil lymphocyte, RBC and platelet counts on day -1, 3, 5, 7, 9, 11, 13, 15, 17 with the MEK-7222K cell analyzer, and the cell count was compared between HS6101 treatment mice and CTX control mice. Another 30 male ICR mice were used for bone marrow colony forming unit (CFU) assay and bone marrow histopathological examination, and they were assigned into normal control, CTX control, HS6101 prevention, HS6101treatment and HS6101 prevention + treatment groups (each n=6). On the day 4 and day 9 after CTX injection, mice were sacrificed and bone marrow cells were collected from the left femur for mononuclear cell (MNC) isolation. 1×104 MNCs were planted in 1.0ml mouse CFU culture medium M3434 and cultured in incubator with the temperature of 37℃, and 5% CO2 for 7 days. After that, granulocyte macrophage-colony-forming unit (GM-CFU), megakaryocyte colony forming unit (MK-CFU), mixture-colony-forming unit (Mix-CFU), burst-forming unit-erythroid (BFU-E) and colony-forming unit-erythroid (CFU-E) were counted. Then the right femur was taken for histopathology examination. Results After CTX injection, counts of WBC, neutrophils, lymphocytes, RBC and platelets of all the mice decreased rapidly. However, the nadirs of WBC, neutrophils and lymphocytes counts in HS6101 prevention group were higher than those in CTX control group, and the counts on day 3 were higher than those in HS6101 treatment group and HS6101 prevention+ treatment group. On day 3, RBC count in HS6101 prevention group was the highest. It was higher on day 5 and day 7 than that of mice in CTX group. In addition, the platelet count in HS6101 prevention group was also the highest on day 3, although that in HS6101 treatment group and 6101 prevention + treatment group was lower than CTX control group. Bone marrow colony forming unit assay showed that the counts of GM-CFU, MK-CFU, BFU-E and CFU-E in all the HS6101 treatment mice were significantly higher than those in CTX control mice. On day 4, histopathological examination of bone marrow from HS6101-treated mice displayed more intact architecture compared with CTX control mice. Three of eighteen (3/18) mice died in HS6101 treatment group, and nine of eighteen (9/18) died in HS6101 prevention + treatment group, suggesting that HS6101 should not be administered after CTX injection. Conclusion Administration of HS6101 at 1h before giving CTX could significantly promote hematopoietic recovery in ICR mice injured by CTX.