SURVIVAL OF SYNCHRONIZED CHINESE-HAMSTER CELLS EXPOSED TO RADIATION OF DIFFERENT LINEAR ENERGY TRANSFER
SURVIVAL OF SYNCHRONIZED CHINESE-HAMSTER CELLS EXPOSED TO RADIATION OF DIFFERENT LINEAR ENERGY TRANSFER
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DOI：
10.1080/09553007514550121
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发表时间：
1975-01-01
影响因子：
2.6
通讯作者：
BURKI, HJ
中科院分区：
文献类型：
--
作者：
BIRD, RP;BURKI, HJ
中国仓鼠V79细胞暴露于电离辐射的广泛的线性能量转移（LET），包括145千伏的X射线和六种不同的重离子加速伯克利重离子线性加速器。离子的LET范围为19 keV/µm至2000 keV/µm。生存曲线测定同步和异步细胞，使用生存的集落形成能力作为end-point.Results与异步文化是类似的结果，以前报道的哺乳动物细胞。随着LET的增加，每剂量的杀伤效率增加，直到碳离子（LET为190 keV/µm）的单细胞存活曲线形状发生变化，从S形变为指数形。随着离子浓度的增加，细胞生长曲线呈指数变化，但单位剂量的效应降低。发现X射线的预期中国仓鼠细胞周期存活曲线变化，主要反映了单细胞外推数的变化，S期晚期细胞对辐射的抵抗力最强。当同步培养物用产生指数存活曲线的重离子照射时，存活曲线与照射的细胞周期时间无关。随着辐射的LET值之间的低和高的极端，减少细胞周期的存活曲线的变化被发现，表明细胞周期的存活曲线的变化作为一个函数的LET增加逐渐减少。
Chinese hamster V79 cells were exposed to ionizing radiations of a wide range of linear-energy transfer (LET), including 145 kV X-rays and six different heavy ions accelerated in the Berkeley heavy-ion linear accelerator. The LET of the ions ranged from 19 keV/µm to 2000 keV/µm. Survival curves were determined for both synchronized and asynchronous cells, using survival of colony-forming capacity as the end-point.Results with asynchronous cultures were similar to results reported previously for mammalian cells. There was increased effectiveness of killing per dose with increased LET until a change in shape of the single-cell survival curves resulted, from sigmoidal to exponential, with carbon ions (LET of 190 keV/µm). With heavier ions, exponential curves were obtained, but with decreased effectiveness per unit dose.Synchronized cultures were obtained by mitotic selection. The expected Chinese hamster cell-cycle survival curve variation was found for X-rays, mainly reflecting the variation in the single-cell extrapolation number, with late-S-phase cells the most resistant to radiation. When synchronized cultures were irradiated with the heavy ions that produce exponential survival curves, the survival curves were independent of the cell-cycle time of irradiation. With radiations of LET values between the low and high extremes, a reduced cell-cycle survival curve variation was found, indicating a gradual reduction in the cell-cycle survival curve variation as a function of increased LET.