Sasaki H
Radiat Res. 1984 Aug;99(2):311-23.
HeLa cells irradiated with a single or two split doses of alpha particles or X rays were observed with time-lapse photography or examined for their colony-forming ability. The cell cycle-dependent variation of cell killing and division delay were compared in synchronous and asynchronous cell populations. Cellular damage by alpha particles was manifested in the form of cessation of division, or death, rather than partial division which was predominant for X irradiation. Furthermore, an increased number of interrupted divisions leading to death following split doses correlated with the lack of production of reparable damage from alpha particles. As to the cell cycle-dependent variation of radiosensitivity, a somewhat different pattern was noted with alpha particles, especially for division delay. The pattern of cell killing with alpha particles was similar to that found with X rays, in that high sensitivity was noted at or close to mitosis, while a resistant peak remained at late S but not in early G1. The pattern of division delay was similar for X rays and alpha particles during G2-M, with a maximum delay at mid G2 and no delay past the transition point, but differed during G1-S. During this period, division delay increased with cell age, whereas it showed a broad peak at G1-S boundary and a trough at late S for X rays. There was a reverse correlation between division delay and cell killing except for G2-M in the case of X rays. However, such was not the case for alpha particles.
用延时摄影观察了用单剂量或两分割剂量的α粒子或X射线照射的HeLa细胞，或检测了它们的集落形成能力。比较了同步和异步细胞群体中细胞杀伤和分裂延迟的细胞周期依赖性变化。α粒子造成的细胞损伤表现为分裂停止或死亡，而不是X射线照射时占主导的部分分裂。此外，分割剂量后导致死亡的中断分裂数量增加与α粒子缺乏可修复损伤的产生相关。关于放射敏感性的细胞周期依赖性变化，α粒子呈现出 somewhat different pattern，尤其是在分裂延迟方面。α粒子的细胞杀伤模式与X射线相似，即在有丝分裂时或接近有丝分裂时敏感性较高，而在S期后期仍有一个抗性峰值，但在G1期早期没有。X射线和α粒子在G2-M期的分裂延迟模式相似，在G2期中期延迟最大，越过转变点后没有延迟，但在G1-S期有所不同。在此期间，分裂延迟随细胞年龄增加，而X射线在G1-S边界处有一个宽峰，在S期后期有一个低谷。除了X射线在G2-M期外，分裂延迟与细胞杀伤之间存在负相关。然而，α粒子并非如此。
