Brooks A L, Griffith W C, Johnson N F, Finch G L, Cuddihy R G
Inhalation Toxicology Research Institute, Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico 87185.
Radiat Res. 1989 Dec;120(3):494-507.
Studies were conducted to determine the effects of BeSO4 or X rays, alone and in combination, on cell cycle kinetics, cell killing, and the production of chromosome aberrations in Chinese hamster ovary (CHO) cells. The concentration of BeSO4 required to kill 50% of CHO cells exposed to BeSO4 for 20 h was determined to be 1.1 mM with 95% confidence intervals of 0.72 to 1.8 mM. During the last 2 h of the 20-h beryllium treatment (0.2 and 1.0 mM), cells were exposed to 0.0, 1.0, or 2.0 Gy of X rays. Exposure to either BeSO4 or X rays produced a change in cell cycle kinetics which resulted in an accumulation of cells in the G2/M stage of the cell cycle. However, combined exposure to both agents resulted in a block similar to that observed following exposure to X rays only. The background level of chromosome damage was 0.05 +/- 0.015 aberrations/cell in the CHO cells. Seven hours after the end of exposure to 0.2 and 1.0 mM beryllium, 0.03 +/- 0.003 and 0.09 +/- 0.02 aberrations/cell, respectively, were observed. The data for chromosome aberrations following X-ray exposure were fitted to a linear model with a coefficient of 0.14 +/- 0.01 aberrations/cell/Gy. When beryllium was combined with the X-ray exposure the interactive response was predicted by a multiplicative model and was significantly higher (P less than 0.05) than predicted by an additive model. The influence of time after radiation exposure on the interaction between beryllium and X rays was also determined. No interaction between beryllium and X-ray exposure in the induction of chromosome-type aberrations (P greater than 0.05) was detected. The frequency of chromatid-type exchanges and total aberrations was significantly higher (P less than 0.05) in the radiation plus beryllium-exposed cells when compared to cells exposed to X rays only, at both 9 and 12 h after X-ray exposure. These data suggest that the multiplicative interaction may be limited to cells in the S and G2 stages of the cell cycle.
开展了多项研究，以确定硫酸铍（BeSO4）或X射线单独及联合作用对中国仓鼠卵巢（CHO）细胞的细胞周期动力学、细胞杀伤及染色体畸变产生的影响。经测定，使暴露于硫酸铍20小时的CHO细胞半数死亡所需的硫酸铍浓度为1.1 mM，95%置信区间为0.72至1.8 mM。在20小时铍处理（0.2 mM和1.0 mM）的最后2小时，细胞暴露于0.0、1.0或2.0 Gy的X射线下。单独暴露于硫酸铍或X射线均会导致细胞周期动力学发生变化，从而使细胞在细胞周期的G2/M期积累。然而，两种因素联合暴露导致的阻滞与仅暴露于X射线后观察到的情况相似。CHO细胞中染色体损伤的背景水平为0.05±0.015个畸变/细胞。在暴露于0.2 mM和1.0 mM铍结束7小时后，分别观察到0.03±0.003和0.09±0.02个畸变/细胞。X射线暴露后染色体畸变的数据拟合为线性模型，系数为0.14±0.01个畸变/细胞/Gy。当铍与X射线联合暴露时，交互反应由乘法模型预测，且显著高于加法模型预测值（P<0.05）。还确定了辐射暴露后时间对铍与X射线之间相互作用的影响。未检测到铍与X射线暴露在诱导染色体型畸变方面存在相互作用（P>0.05）。与仅暴露于X射线的细胞相比，在X射线暴露后9小时和12小时，辐射加铍暴露细胞中的染色单体型交换频率和总畸变率均显著更高（P<0.05）。这些数据表明，乘法相互作用可能仅限于细胞周期S期和G2期的细胞。
