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低剂量辐射诱导小鼠胸腺细胞DNA裂解适应性反应的剂量率效应

刘淑春,吕喆,王珍琦,刘 扬,刘光伟,龚守良*   

  1. 吉林大学公共卫生学院 卫生部放射生物学重点实验室,吉林 长春130021
  • 收稿日期:2003-03-18 修回日期:1900-01-01 出版日期:2004-09-28 发布日期:2004-09-28
  • 通讯作者: 龚守良

Dose-rate effects of adaptive response of thymocyte DNAlysis induced by low dose ionizing radiation in mice

LIU Shu-chun, LU Zhe, WANG Zhen-qi, LIU Yang, LIU Guang-wei, GONG Shou-liang*   

  1. MH Radiobiology Research Unit, School of Public Health, Jilin University,Changchun 130021, China
  • Received:2003-03-18 Revised:1900-01-01 Online:2004-09-28 Published:2004-09-28
  • Contact: GONG Shou-liang

摘要: 目的:观察低剂量辐射诱导胸腺细胞DNA裂解适应性反应的剂量率效应。方法:用X射线照射Kunming雄性小鼠,其诱导剂量(D1)及其后攻击剂量(D2)分别是75 mGy和1.5 Gy,D1剂量率为6.25、12.5、25、50、100和200 mGy•min-1,D2剂量率为287 mGy•min-1,D1 和D2间隔6 h。通过荧光分光光度计检测DNA裂解断片的变化。结果:D2组胸腺细胞DNA裂解率明显高于假照组(P<0.001);当D1剂量率为6.25、12.5和25 mGy•min-1,D1+D2组DNA裂解率明显低于D2组(P<0.05或P<0.01)。 结论:当D1在75 mGy,剂量率为6.25~25 mGy•min-1;D2为1.5 Gy,剂量率为287 mGy•min-1;D1和D2间隔6 h,可在全身照射条件下诱导小鼠胸腺细胞DNA裂解的适应性反应。

关键词: 电离, 辐射剂量, DNA裂解, 适应性反应

Abstract: Objective To observe the dose-rate effects of adaptive response of thymocyte DNA lysis induced by low dose radiation. Methods Kunming male mice were irradiated with the inductive dose (D1: 75 mGy; dose rate: 6.25, 12.5, 25, 50, 100, and 200 mGy•min-1) and the challenging dose (D2: 1.5 Gy; dose rate:287 mGy•min-1), the interval between D1 and D2 was 6 hours. The DNA lytic fragmentation was measured with fluorospectrophotometry. Results The DNA lytic rate in the D2 group was significantly higher than that in sham-irradiation group; when the dose rates were 6.25, 12.5 and 25 mGy•min-1,the DNA lytic rates in D1+D2 groups were significantly lower than those in the D2 group (P<0.05 or P<0.01). Conclusion When the mice are irradiated with 75 mGy (D1: 6.25~25 mGy•min-1) 6 hours before 1.5 Gy (D2: 287 mGy•min-1) exposure, the adaptive response of thymocyte apoptosis can be induced under the condition of whole-body irradiation.

Key words: ionizing, radiation dosage, DNA lysis, adaptive response

中图分类号: 

  • Q691