Potentially lethal damage versus sublethal damage: independent repair processes in actively growing Chinese hamster cells.
Potentially lethal damage versus sublethal damage: independent repair processes in actively growing Chinese hamster cells.
复制标题
潜在致死损伤与亚致死损伤：活跃生长的中国仓鼠细胞的独立修复过程。
作者：
H. Utsumi;M. Elkind
生长活跃的V79细胞在x射线照射后用等渗磷酸盐缓冲液(PBS)处理的细胞比等渗磷酸盐缓冲液(PBS)处理的细胞或照射后立即用完全培养液孵育的细胞更敏感。辐照细胞的敏化是由PBS中的低渗和高渗盐浓度引起的，强烈地依赖于温度和时间，主要是由于单剂量存活曲线的最终斜率的增加。在两个X射线剂量组分后，每一组分经等渗后处理致敏的细胞的净反应与等渗处理的细胞相似，表明亚致死损伤修复不受致死性损伤表达增强的影响。前者的修复速度比后者更快，进一步表明修复损害的速度比修复亚致命性损伤的速度更快，这进一步表明，修复损害具有潜在的致命性。有人提出，在x射线照射后，由于DNA与核膜和/或DNA与核蛋白基质之间的结构关系不稳定，损伤的表达增强，这是由于非等渗处理产生了更多的渗透性变化。
Actively growing V79 Chinese hamster cells, treated with anisotonic phosphate-buffered saline (PBS) after x irradiation, are more sensitive than cells treated with isotonic PBS or cells promptly incubated with complete medium immediately after irradiation. The sensitization of irradiated cells results from hypotonic as well as hypertonic NaCl concentrations in PBS, is strongly dependent on both temperature and time, and is mainly due to an increase in the final slope of the single-dose survival curve. After two x-ray dose fractions, the net response of cells sensitized after each fraction by anisotonic post-treatment is similar to that obtained for isotonically treated cells and indicates that sublethal damage repair is not influenced by the enhanced expression of lethal damage. Independence of the repair of damage which is potentially lethal from the repair of damage which is sublethal is further suggested by the more rapid rate of the former compared to that of the latter. The proposal is advanced that the enhanced expression of damage which, after x irradiation, can be shown to be potentially lethal results from a destabilization of the structural relationship between DNA and the nuclear envelope, and/or DNA and the nuclear protein matrix, as a consequence of osmotic changes producedmore » by anisotonic treatment.« less