| Objective: Study the protective effects of amifostine on mice with irradiating damageinduced by60Co-gamma-ray, especially the protection of bone marrow cell. Methods:According to the weight, healthy ICR mice were randomly divided into normal group, modelgroup, low dose group, medium dose group and high dose group with the dosage of0,0,120,240,480mg/kg. The drug was tail intravenous injection in each group every day forsuccessive3days and then all animals expect normal group were irradiated by60Co-gamma-ray. The dose of30-day survival rate test is8Gy, and the others were6Gy.Then observe30–day-survival rate and the average survival time in mice and the bodyweight within28days. The number of peripheral blood white blood cells (WBC), red bloodcells (RBC), lymphocytes (LYMPH) and platelets (PLAT) were counted on1,4,7,14,21and28day after irradiating. And then observe the indices of oxidative stress, hematopoietic andimmune organs on3day after irradiating. And then54healthy ICR mice were randomlydivided into normal group, model group and amifostine group with the dosage of0,0,480mg/kg. The drug was tail intravenous injection in each group every day for successive3daysand then all animals expect normal group were irradiated by60Co-gamma-ray. Assayapoptosis of bone marrow cells on6,12and24hour after irradiating. Results:(1)30-day-survival rate and the average survival time: Compared with model group, the average survivaltime of120mg/kg dose group,240mg/kg dose group and480mg/kg dose group wereextended, especially in480mg/kg dose group was increased significantly.(2) Weight: Modelgroup,120mg/kg dose group,240mg/kg dose group and480mg/kg dose group all loseweight on1and4day after irradiating and the weight of all experiment groups increased on7day after irradiating.(3) Hematology: On7day after irradiating, the numbers of WBC of allexperiment groups fell sharply compared with normal group, and in480mg/kg dose groupwas increased significantly compared with model group. On14day after irradiating, thenumbers of WBC of all experiment groups were still reduced except480mg/kg dose group,but480mg/kg dose group was recovery. On21day after irradiating, all experiment groupswere recovery. On1,4,7day after irradiating, the numbers of RBC of all experiment groupswere reduced compared with normal group. On14day after irradiating, compared withnormal group, the numbers of RBC of model group and120mg/kg dose group were reduced significantly. On21day after irradiating, all experiment groups were recovery. On1,4,7dayafter irradiating, the numbers of LYMPH of all experiment groups were reduced comparedwith normal group, and in480mg/kg dose group was increased significantly compared withmodel group. On14day after irradiating, compared with normal group, the numbers of RBCof model group,120mg/kg dose group and240mg/kg were reduced significantly. On28dayafter irradiating, all experiment groups were recovery. On14day after irradiating, thenumbers of PLAT of model group and120mg/kg dose group were reduced significantlycompared with normal group.(4) Oxidative Stress Indicators: Compared with normal group,the active of SOD in serum in the four experiment groups were decreased significantly, butcompared with model group, the active of SOD in240mg/kg dose group and480mg/kg dosegroup were increased significantly on3day after irradiating. And Compared with normalgroup, the level of MDA in serum in model group and120mg/kg dose group were increasedsignificantly, but the level of MDA in240mg/kg dose group and480mg/kg dose group werelower than model group on3day after irradiating.(5) TI and SI: Compared with normalgroup, the thymus index and spleen index of four experiment groups all were decreasedsignificantly, but compared with model group, the thymus index and spleen index of120mg/kg dose group,240mg/kg dose group and480mg/kg dose group were increasedsignificantly.(6) Thymus, spleen and bone marrow histopathology: The cortex LYMPH of model groupand amifostine group were reduced and atrophy. Compared with the normal group, the lymphoperia andspleen hematopoietic cells of the model group were damaged and RBC increased. Compared with themodel group, the LYMPH and hematopoietic cells of amifostine group increased, and thesplenic corpuscle number and volume were also increased. The bone marrow hematopoieticcells of model group were decreased, filled with a lot of mature red blood cells and marrowdysfunction. Compared with the model group, the bone marrow cavity of amifostine group had morehematopoietic cells.(7) Apoptosis Rate: The cell apoptosis rate increased in24hour afterirradiating. Compared with normal group, the cell apoptosis rate of model group wasincreased significantly. Amifostine can obviously decrease apoptosis rate of bone marrowcells, and compared with model group, the difference was significant. Conclusions:Amifostine can improve the30day survival rate of radiation mice and prolong survival timeof radiation mice, promote WBC, RBC, LYMPH and PLAT recovery, increase the thymusindex and spleen index, strengthen the SOD activity and reduce the MDA level. So amifostinehas protective effects on the blood system, antioxidant system, immune system andhematopoietic system on mice with the irradiating damage induced by gamma-ray. Objective: HL-60cells, K562cells cultured and bone marrow hematopoietic stemcells/progenitor cells obtained by the technology of Magnetic activated cell sorting (MACS)to further explore the mechanism of radiation caused bone marrow damage and themechanism of amifostine impair radiation-induced apoptosis of bone marrow cells. Methods:HL-60cells and K562cells were primed with different doses of amifostine15-30min priorto60Co-gamma-ray, apoptosis rate was measured following24h exposure;30healthy ICRmice were randomly divided into normal group, model group and amifostine group with thedosage of0,0,480mg/kg. The drug was tail intravenous injection in each group every dayfor successive3days and then all animals expect normal group were irradiated by60Co-gamma-ray. Assay apoptosis of bone marrow CD117+cells on24hour after irradiating.Then determine protein quantitative of p53, p21, mdm2and c-myc by Western Blot. Results:(1) The apoptosis rate of HL-60increased on24hour after irradiating and positively related tothe amifostine dose.(2) The apoptosis rate of K562increased on24hour after irradiating andpositively related to the amifostine dose.(3) The percentage of CD117+cells in model groupwas remarkable declined compared with normal group, while the percentage of CD117+cellsin amifostine group was increased compared with model group on24hour after irradiating.(4)The apoptosis rate of bone marrow hematopoietic stem cells/progenitor cells in model groupand amifostine group were increased compared with normal group, while the apoptosis rate ofamifostine group was declined compared with model group.(5) The results of western blotshowed that amifostine could down-regulate p21and c-myc, but up-regulate mdm2of bonemarrow hematopoietic stem cells/progenitor cells. Conclusions:(1) Amifostine can influencethe p53-related genes, such as p21, mdm2and c-myc. These genes regulate each other toinhibit apoptosis and protect the bone marrow cells from radiation injury.(2) Amifostine has adual role on apoptosis, and this effect may be related to cell types. |
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