Mendonca M S, Kurohara W, Antoniono R, Redpath J L
Department of Radiological Sciences, University of California, Irvine 92717.
Radiat Res. 1989 Aug;119(2):387-93.
The plating efficiency (PE) of a gamma-irradiated (7 Gy) human cell hybrid line (HeLa X skin fibroblast, designated as CGL1) has been measured as a function of time postirradiation and compared to that of unirradiated cells at similar cell densities and under the same growth conditions. The results indicate that following irradiation, the PE of the irradiated cells initially increases but never returns to that of unirradiated cells during the experimental period that we have examined. Furthermore, after a period of 9 to 10 days (equivalent to at least 10 cell doublings) postirradiation and plating, the PE of the irradiated cells begins to decrease and continues to do so over the next 5 days. A decrease does not occur in unirradiated cells until much later (i.e., Day 15) corresponding to at least 5 additional cell doublings. The data are discussed in terms of a delayed expression of lethal mutations. The possible impact of these observations on the estimation of radiation-induced transformation frequencies is also considered.
已测量了经γ射线照射（7戈瑞）的人细胞杂交系（HeLa与皮肤成纤维细胞杂交，命名为CGL1）的平板接种效率（PE），该效率是照射后时间的函数，并与处于相似细胞密度和相同生长条件下的未照射细胞的平板接种效率进行了比较。结果表明，照射后，在我们所研究的实验期间，照射细胞的PE最初会升高，但从未恢复到未照射细胞的水平。此外，在照射和平板接种9至10天（相当于至少10次细胞倍增）后，照射细胞的PE开始下降，并在接下来的5天内持续下降。未照射细胞直到很久以后（即第15天）才出现下降，此时相当于至少额外进行了5次细胞倍增。这些数据将根据致死突变的延迟表达进行讨论。还考虑了这些观察结果对辐射诱导转化频率估计的可能影响。
