Repair of Cell Killing and Neoplastic Transformation at Reduced Dose Rates of 60Co γ-Rays
Repair of Cell Killing and Neoplastic Transformation at Reduced Dose Rates of 60Co γ-Rays
复制标题
降低 60Co γ 射线剂量率修复细胞杀伤和肿瘤转化
DOI：
10.2307/3577505
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发表时间：
1980
期刊：
影响因子：
11.2
通讯作者：
M. M. Elkind
中科院分区：
文献类型：
--
作者：
A. Han;C. Hill;M. M. Elkind
使用C3 H/10 T1/2小鼠胚胎来源的细胞系，我们测量了细胞暴露于急性（100 rad/min）和降低（2.5，0.5和0.1 rad/min）剂量率的60 Co γ射线后的存活率和肿瘤转化率。通常在哺乳动物细胞中观察到的典型情况是，在降低的剂量率下，10 T1/2细胞的存活率随着剂量率的降低而增加，这是由于照射期间亚致死损伤的修复。急性暴露于60 Co γ射线后的诱导曲线与先前报道的50 kV X射线相似;频率最初迅速上升，达到约3 × 10-3转化体/存活者的平台。降低剂量率的转换感应曲线，而类似的形状，为高剂量率，表现出强烈的依赖剂量率。在低剂量区，所有降低剂量率的诱导频率均低于100 rads/min。（即，0至150拉德），我们的结果是最广泛的在100和0.1拉德/分钟。虽然在低剂量区的每组数据拟合相当好的线性剂量依赖，在0.1拉德/分钟的回归线的斜率是在100拉德/分钟的一半左右。我们得出结论，亚有效的转化损伤，以及亚致死损伤，在低剂量率照射修复。
Using the C3H/10T½ mouse embryo-derived cell line, we measured the survival and incidence of neoplastic transformation following exposures of the cells to 60Co γ-rays at an acute (100 rads/min) and at reduced (2.5, 0.5, and 0.1 rad/min) dose rates. Typical of what is generally observed with mammalian cells, at reduced dose rates, the survival of 10T½ cells increases as the dose rate is decreased due to the repair of sublethal damage during irradiation. The induction curve following acute exposures of 60Co γ-rays is similar to that previously reported for 50-kV X-rays; the frequency initially rises rapidly, reaching a plateau of about 3 × 10-3 transformants/survivor. The transformation induction curves for the reduced dose rates, while similar in shape to that for the high dose rate, exhibit a strong dependence on dose rate. All of the induction frequencies for reduced dose rates lie below those for 100 rads/min. In the low-dose region ( i.e. , 0 to 150 rads), our results are most extensive at 100 and at 0.1 rad/min. While each set of data in the low-dose region is fitted quite well by a linear dose dependence, the slope of the regression line at 0.1 rad/min is about one-half of that at 100 rads/min. We conclude that subeffective transformation damage, as well as sublethal damage, is repaired during low-dose-rate irradiation.