Kruszewski M, Green M H, Lowe J E, Szumiel I
Department of Radiobiology and Health Protection, Institute of Nuclear Chemistry and Technology, Warsaw, Poland.
Mutat Res. 1995 Feb;326(2):155-63. doi: 10.1016/0027-5107(94)00163-y.
The L5178Y murine lymphoma subline LY-R is twofold more resistant to killing by ionizing radiation than the subline LY-S. In contrast, LY-R cells are more sensitive to killing by hydrogen peroxide: at 37 degrees C LY-R cells are 1.4 times more sensitive to the killing effect of H2O2 than LY-S cells. Pretreatment with the iron chelator desferroxamine followed by hydrogen peroxide treatment at 37 degrees C gives a considerable sparing effect, which is substantially greater for the LY-R subline than for the LY-S subline. This is reflected in the initial DNA damage (estimated by single cell gel electrophoresis), survival and mutation frequency in the HGPRT locus. Similar results have been obtained with calcium chelators, which, according to recent findings (Sandström and Granström 1993), also are efficient iron chelators. In contrast, the response to X-rays is not modified by the above chelators, with the exception of mutation frequencies: lower mutant numbers are found in desferroxamine pretreated LY-R cells.
L5178Y小鼠淋巴瘤亚系LY - R对电离辐射杀伤的抗性是亚系LY - S的两倍。相比之下，LY - R细胞对过氧化氢杀伤更敏感：在37℃时，LY - R细胞对H2O2杀伤作用的敏感性是LY - S细胞的1.4倍。用铁螯合剂去铁胺预处理，随后在37℃进行过氧化氢处理，可产生显著的保护作用，LY - R亚系的这种作用比LY - S亚系大得多。这体现在初始DNA损伤（通过单细胞凝胶电泳估计）、HGPRT位点的存活率和突变频率上。钙螯合剂也得到了类似结果，根据最近的研究结果（桑德斯特伦和格兰斯特伦，1993年），钙螯合剂也是有效的铁螯合剂。相比之下，除了突变频率外，上述螯合剂对X射线的反应没有改变：在去铁胺预处理的LY - R细胞中发现的突变体数量较少。
