Sensitization of mouse L cells to ultraviolet light by low amounts of bromodeoxyuridine.
Sensitization of mouse L cells to ultraviolet light by low amounts of bromodeoxyuridine.
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少量溴脱氧尿苷使小鼠 L 细胞对紫外线敏感。
DOI：
10.2307/3575822
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发表时间：
1982
影响因子：
3.4
通讯作者：
J. Cleaver
中科院分区：
文献类型：
--
作者：
G. Thomas;M. Maloney;J. Cleaver
小鼠L细胞DNA中至少5%的胸腺嘧啶被溴沙拉星取代，对紫外线的致死最大敏感度可达4~5倍。溴沙拉星的替代(通过与溴脱氧尿苷孵育细胞)导致每单位辐射剂量的DNA损伤总数净增加，这是由于与溴沙拉星光解相关的断裂。来自D/sub37/的临界靶点大小的估计表明，溴沙星替代引起的额外的细胞毒性可能与在DNA的大区域产生一些断裂有关，这表明染色体异常水平的损伤可能是致命性事件。用胸腺嘧啶核苷中的细胞生长稀释溴沙星取代的DNA，表明单链或双链DNA取代的细胞的敏感性没有差别。每次分裂时，含溴沙星的染色体数目减半，敏感度下降，当分裂数足以产生一个或更少的替代染色体时，敏感度达到正常。
Substitution of bromouracil for at least 5% of the thymines in DNA of mouse L cells causes a maximum sensitization of four- to fivefold to killing by ultraviolet light. The substitution of bromouracil (by incubation of cells with bromodeoxyuridine) results in a net increase in the total number of lesions in DNA per unit dose of radiation, owing to the breaks associated with bromouracil photolysis. Estimates of critical target size from the D/sub 37/ indicate that the additional cytotoxicity caused by bromouracil substitution may be associated with the production of a few breaks in large regions of DNA, suggesting that damage at the level of a chromosome aberration may be the lethal event. Dilution of bromouracil-substituted DNA by growth of cells in thymidine indicated that there was no difference between the sensitivity of cells substituted in one or both strands of DNA. The sensitivity decreased as the number of chromosomes containing bromouracil halved at each cell division and reached normal sensitivity when the number of divisions was sufficient to produce one or fewer substituted chromosomes per cell.