SEQUENTIAL EXPOSURES OF MAMMALIAN-CELLS TO LOW-LET AND HIGH-LET RADIATIONS .1. LETHAL EFFECTS FOLLOWING X-RAY AND NEON-ION IRRADIATION
SEQUENTIAL EXPOSURES OF MAMMALIAN-CELLS TO LOW-LET AND HIGH-LET RADIATIONS .1. LETHAL EFFECTS FOLLOWING X-RAY AND NEON-ION IRRADIATION
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DOI：
10.2307/3575541
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发表时间：
1981-01-01
影响因子：
3.4
通讯作者：
TOBIAS, CA
中科院分区：
文献类型：
--
作者：
NGO, FQH;BLAKELY, EA;TOBIAS, CA
设计实验来检验低和高LET（线性能量转移）辐射之间细胞杀伤的独立作用假设。在Bevalac中，单独使用布拉格峰氖离子或与X射线组合照射异步中国仓鼠V79细胞[肺]。暴露于氖离子的细胞的存活曲线在外观上是指数的，没有证据表明分剂量修复。相对于仅X射线的存活曲线，在氖离子的引发剂量之后不久用分级剂量的X射线照射的细胞的存活率曲线具有减小的肩（Dq）。相反，在X射线引发剂量后不久，用分级剂量的氖离子照射的细胞的存活曲线显示与仅使用氖离子的存活曲线相比，平均致死剂量（D0）降低。这两种效应都随着预激剂量的增加而增加。带电粒子和X射线各自产生相互作用的损伤，并表明低和高LET辐射通过协同模式起作用。此外，选择性分馏间隔的实验表明，所描述的相互作用效应随着分馏时间的增加而减少，而不管辐射序列如何。显然，即使是参与相互作用过程的高LET诱导的损伤也可以被细胞修复。
Experiments were designed to test the independent action hypothesis for cell killing between low- and high-LET [linear energy transfer] radiations. Asynchronous Chinese hamster V79 cells [lung] were irradiated at a Bevalac with Bragg-peak neon ions alone or in combination with X-rays. The survival curve for cells exposed to neon ions was exponential in appearance, with no evidence of split-dose repair. The survival rate curve for cells irradiated with graded doses of X-rays shortly after a priming dose of neon ions had a reduced shoulder (Dq) relative to the X-ray only survival curve. Conversely, the survival curve for cells irradiated with graded doses of neon ions shortly after a priming dose of X-rays showed a reduced mean lethal dose (D0) compared to the neon-only survival curve. Both of these effects increased with the size of the priming dose. The charged particles and X-rays each produce damage which interacts with the other, and suggest that low- and high-LET radiations act by a synergistic mode. In addition, experiments with selective fractionation intervals demonstrated that the interaction effects described diminish with increased fractionation time, regardless of the radiation sequence. Apparently, even the high-LET-induced damage which is involved in the interaction process can be repaired by cells.