Dewey D L, Williams K B
Cancer Research Campaign, Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, England.
Radiat Res. 1988 Jan;113(1):102-11.
The effect of oxygen on cell cycle delay by low doses of radiation on synchronized Harding Passey melanoma cells has been studied. Cells were irradiated 5 h after subculturing into fresh medium, and the delay before the start of S was measured. DNA synthesis was measured by frequent pulse labeling of the cells with radioactive thymidine to obtain the S-phase profile. The amount by which the irradiated cells S-phase profile had to be moved in time so that both the ascending and descending portions of the first S phase overlayed that of the controls was used as a measure of the delay. The magnitude of the delay was exponentially related to radiation dose and the effect of irradiating in the absence of oxygen was a dose multiplying factor of 2.5. This was similar to the oxygen effect on survival for cells irradiated under the same conditions.
研究了氧气对低剂量辐射导致同步化的哈丁·帕西黑色素瘤细胞细胞周期延迟的影响。将细胞接种到新鲜培养基中5小时后进行辐照，并测量S期开始前的延迟时间。通过用放射性胸苷频繁脉冲标记细胞来测量DNA合成，以获得S期图谱。将受辐照细胞的S期图谱在时间上移动的量，使得第一个S期的上升和下降部分与对照的重叠，以此作为延迟的度量。延迟的幅度与辐射剂量呈指数关系，并且在无氧条件下辐照的效应是剂量倍增因子为2.5。这与在相同条件下辐照的细胞的存活氧效应相似。
