碳离子全身辐照致小鼠造血系统的损伤

目的：探讨不同剂量碳离子全身辐射对小鼠造血系统的损伤及其恢复情况。方法：分别用0、0.5、1、4、6 Gy碳离子束对小鼠进行一次性全身辐照，在辐照后第1、3、8天用碱性彗星电泳实验和流式细胞术分别检测小鼠骨髓单核细胞DNA损伤与细胞周期分布，并检测外周血细胞含量及脾脏指数。结果：与对照组相比，碳离子全身辐照导致小鼠骨髓单核细胞DNA损伤，其损伤程度与辐照剂量呈正相关（r均≤0.96，P均 < 0.01），且在辐照后第3天损伤最为严重，在辐照后第8天，DNA损伤与对照组相比，差异仍显著（P均 < 0.01）。碳离子全身辐照引起小鼠骨髓单核细胞周期产生明显的S期和G2/M期阻滞，以及外周血有核细胞数急剧下降和脾脏指数降低（P均 < 0.05），且随辐照剂量的增加而趋于严重。在辐照后第8天，小鼠骨髓单核细胞S期阻滞基本解除（P > 0.05），但有核细胞数和脾脏指数并未明显回升（P均 < 0.05）。结论：不同剂量碳离子全身辐照均使小鼠造血系统严重受损。在0.5~6 Gy碳离子束照后第8天，小鼠骨髓细胞DNA损伤仍较严重，造血功能未明显恢复。

Total body irradiation of mice with carbon-ion caused damage to the hematopoietic system

OBJECTIVE: To explore the damage and recovery of hematopoietic system in mice after total body irradiation (TBI) with different doses of carbon-ion. METHODS: Female BABL/c mice were irradiated with 0.5,1,4,6 Gy carbon-ion beam. DNA damage in bone marrow monocytes cells (BMMCs) were detected by alkaline comet assay and cell cycle distributions were detected by FACS. Peripheral blood cell counts and spleen index were detected at 1^st,3^rd,8^th days after irradiation. RESULTS: Compared to the control group,carbon-ion TBI induced serious BMMNCs DNA damage in a dose-dependent manner (all r ≤ 0.96,P < 0.01). The most serious damage occurred at the 3^rd day post-irradiation. At the 8^th day after irradiation,DNA damage was still serious (P < 0.01). Carbon-ion TBI also caused dose-dependent bone marrow cells S phase and G2/M phase arrests and decrease of peripheral blood nucleated cells and spleen index. At the 8^th day after irradiation,the S phase arrests of bone marrow cells has been alleviated to some extent,but the decrease of peripheral blood nucleated cells and spleen index were still significant. CONCLUSION: Carbon-ion TBI caused serious damage to the hematopoietic system of mice in a dose-dependent manner. At the 8^th day after irradiation,the BMMCs DNA damage was still serious,and hematopoiesis did not recover.