Study On The Mechanism Of Human Umbilical Cord Blood Stem Cells Against Electrical Radiation Injury

[Objective] Study on human umbilical cord blood stem cells to ionizing radiation-induced hematopoietic injury of experimental animals.[Methods] The 80 mice were randomly divided into normal group, experimental group(which is divided into a radiation group, treatment group and strengthen group). The experimental group were given 1h of the 1 Gy radiation, while the radiation group does not do any processing after radiation, the treatment group and strengthen group were given stem cells by caudal vein of mice(shots are 230 IU/g). The strengthen group given stem cells after 24 h again. All mice were executed in batches to routine blood tests for blood, flow cytometry, bone marrow testing at 2 d, 3 d, 7 d, 14 d.[Results]1. Peripheral blood cell: The radiation group in the experimental group compared to the normal group, white blood cells, red blood cells, lymphocytes,mononuclear cells, hemoglobin count dropped significantly, there were significant differences(F=4.67~33.24, q=3.37~13.56, P<0.05). The white blood cells, red blood cells, lymphocytes, monocytes, and hemoglobin counts in treatment group and strengthen group were significantly higher than radiation group(F=22.19~31.22, q=3.69~7.55,P<0.05). The CD4+total cells, CD4+/CD8+cells ratio of mice in radiation group were significantly higher than normal group after radiation, the differences were significant(F=19.96~25.45, q=3.03~4.95, P<0.05). Compared with the radiation group, the CD4+total cells and CD4+/CD8+cells of treatment group and strengthen group were decreased after the injection of stem cells from human umbilical cord blood(F=5.53 ~ 11.64,q=4.03~9.50, P<0.05), the difference was statistically significant. 2. Myelogram: The radiation group in the experimental groups compared with the normal group, expression of Bcl-2 protein significantly reduced, there were significant differences(F=17.09 ~30.08, q=3.72~12.17, P<0.05). The Bcl-2 protein expression in the treatment group and strengthen group were significantly higher than radiation group(F=5.19 ~ 13.22,q=3.79 ~ 8.39, P<0.05), the difference was statistically significant; After radiation, the treatment group and strengthen group injected with stem cells from human umbilical cord blood, their nucleus cracking increased and fluorescence enhancement than radiation group.[Conclusion] Human umbilical cord blood stem cells in mice after 1 Gy irradiation injury of hematopoietic system have certain repair effect.