中文摘要：

目的对IRM-2、ICR及615小鼠骨髓细胞体外照射后细胞损伤进行比较研究,探讨IRM-2小鼠的抗辐射损伤机制。方法用常规法进行外周血白细胞和骨髓有核细胞计数;应用化学发光法检测不同剂量γ射线对小鼠骨髓细胞活力的影响;用PA法（FITC-Annexin V和PI标记法）检测骨髓细胞凋亡。结果IRM-2小鼠骨髓细胞和外周血白细胞计数高于ICR、615小鼠,经统计学处理后差异有显著性（P〈0.01）。经1 Gy、4 Gy照射后6 h,IRM-2、ICR、615小鼠骨髓细胞相对活力分别为86.6%和79.3%,77.5%和70.4%,77.4%和68.7%,IRM-2小鼠与ICR、615小鼠比较,细胞活力有所提高,IRM-2小鼠骨髓造血细胞死亡率及凋亡率低于ICR及615小鼠。结论IRM-2小鼠有较强的免疫及造血功能,骨髓造血细胞凋亡率低于ICR及615小鼠,其抗辐射机制仍需进一步研究。

英文摘要：

Objective To compare the radiosensitivity of bone marrow cells from 3 strains of mice, and to serve the studies on mechanism of radiation-resistance. Methods The damaging effect of 7-radiation in vitro on BM cell activity was determined by bioluminescence assay. The radiation-induced apoptosis in BM ceils was assayed by FITC-annexin V/PI staining. Results The bone marrow nucleated cells and peripheral blood leukocyte counts in IRM-2 mice were significantly greater than those in ICR and 615 mice （P 〈 0.01 ）. Ionizing radiation-induced BM cell damage in IRM-2 mice was similar to those in ICR and 615 mice at 6 hrs after exposure in vitro to 1 Gy and 4 Gy T-radiation. Conclusions The data suggest that hematopoietie function of IRM-2 mice is stronger than that in ICR and 615 mice. There are no differences in radiation-induced damage in vitro of the bone marrow cells in the 3 mouse strains. The mechanisms by which IRM-2 mice are more resistant to radiation damage need to be further explored.