Suzuki M, Watanabe M, Suzuki K, Nakano K, Matsui K
Division of Radiation Biology, Saitama, Japan.
Int J Radiat Biol. 1992 Nov;62(5):581-6. doi: 10.1080/09553009214552501.
We have studied induction and repair of chromosome damage induced by high linear energy transfer (LET) heavy ions in G1/G0 interphase Syrian golden hamster embryo (SHE) cells as revealed by the premature chromosome condensation (PCC) technique. The number of chromosome breaks in condensed chromosomes induced by high LET heavy ions was higher than those induced by 137Cs gamma-rays. Compared with 137Cs gamma rays, the relative biological effectiveness (RBE) for PCC breaks was 1.5 for 35 keV/microns 4He ions, 1.9 for 77keV/microns 4He ions, and 2.5 for 530keV/microns 14N ions. Although 95% of the PCC breaks induced by gamma-rays rejoined during 8 h post-irradiation incubation, only 35-45% of fragments induced by high LET radiations rejoined in the same time. These results suggest that there is a difference, spatial or qualitative, in the initial chromosome damage produced by high LET radiations and low LET radiations.
我们利用早熟染色体凝集（PCC）技术研究了高传能线密度（LET）重离子在G1/G0间期叙利亚金仓鼠胚胎（SHE）细胞中诱导的染色体损伤的诱导和修复情况。高LET重离子诱导的凝缩染色体中的染色体断裂数量高于137Csγ射线诱导的数量。与137Csγ射线相比，35 keV/μm 4He离子诱导PCC断裂的相对生物效应（RBE）为1.5，77keV/μm 4He离子为1.9，530keV/μm 14N离子为2.5。尽管γ射线诱导的95%的PCC断裂在照射后8小时的孵育过程中重新连接，但高LET辐射诱导的片段在同一时间内只有35-45%重新连接。这些结果表明，高LET辐射和低LET辐射产生的初始染色体损伤在空间或性质上存在差异。
