Meechan P J, Griffiths T D
Radiat Res. 1984 Nov;100(2):282-9.
Existence of a substantial fraction of replicon initiation events refractory to the effects of X irradiation in Chinese hamster cells has been reported by several laboratories. The work reported here examined whether this apparently refractive fraction resulted from a delayed inhibition of initiation events. Data obtained from velocity sedimentation studies indicated that the extent of inhibition increased over the first hour after irradiation from 35% inhibition immediately following exposure to 3 kR to 75% inhibition of initiation 1 hr after irradiation. Analysis of subsequent recovery of initiation radiosensitivity was performed using DNA fiber autoradiograms prepared from cells incubated up to 4 hr between 2-kR exposures. The data from these experiments indicated that some recovery occurs within 1 hr of irradiation and thus separation of the inhibition and recovery processes in V-79 cells may not be feasible.
几个实验室报告称，在中国仓鼠细胞中存在相当一部分复制子起始事件对X射线照射的影响具有抗性。本文报道的研究探讨了这一明显具有抗性的部分是否是由起始事件的延迟抑制导致的。速度沉降研究获得的数据表明，照射后的第一个小时内，抑制程度从照射后立即受到3 kR照射时的35%抑制增加到照射后1小时时起始的75%抑制。使用在2-kR照射之间培养长达4小时的细胞制备的DNA纤维放射自显影片，对随后起始放射敏感性的恢复进行了分析。这些实验的数据表明，在照射后1小时内会发生一些恢复，因此在V-79细胞中分离抑制和恢复过程可能不可行。
