Rice G C, Spiro I J, Ling C C
Int J Radiat Oncol Biol Phys. 1985 Oct;11(10):1817-22. doi: 10.1016/0360-3016(85)90038-0.
We have examined cytokinetic perturbations induced in Chinese hamster V-79 cells in vitro during and following exposure to chronic hypoxia employing simultaneous flow cytometric measurement of incorporated BrdUrd and DNA content. These data indicate hypoxia inhibited G1 progression into S-phase, but did not significantly delay G2M division and progression into G1. Also, upon reaeration after 20 hr in hypoxia, cells originally in G1 exhibited significant kinetic delay. BrdUrd pulse/chase and pulse/fix data indicated DNA replication was reduced, but not completely inhibited during hypoxia. Also, between 6 and 20 hr of chronic hypoxia and following reaeration, a subset of the original S-phase cells overreplicated their DNA, such that these cells had greater than 2C DNA content. This subpopulation was estimated on the average to comprise approximately 20% of the total population (30% of the treated S-phase subpopulation) by 24 hr following reaeration after 20 hr hypoxia. These results are discussed in light of the similarities between overreplication and gene amplification observed under certain conditions with other agents, which like chronic hypoxia, are used to transiently disrupt DNA synthesis.
我们运用同时流式细胞术测量掺入的溴脱氧尿苷（BrdUrd）和DNA含量，研究了中国仓鼠V - 79细胞在体外暴露于慢性缺氧期间及之后所诱导的细胞动力学扰动。这些数据表明，缺氧抑制了G1期向S期的进展，但并未显著延迟G2M期分裂以及向G1期的进展。此外，在缺氧20小时后再通气时，原本处于G1期的细胞表现出显著的动力学延迟。BrdUrd脉冲/追踪和脉冲/固定数据表明，DNA复制减少，但在缺氧期间并未完全受到抑制。而且，在慢性缺氧6至20小时期间以及再通气后，一部分原本处于S期的细胞过度复制了其DNA，使得这些细胞的DNA含量大于2C。在缺氧20小时后再通气24小时时，估计这个亚群平均约占总群体的20%（处理后的S期亚群的30%）。我们根据在某些条件下与其他试剂观察到的过度复制和基因扩增之间的相似性来讨论这些结果，这些试剂与慢性缺氧一样，被用于短暂干扰DNA合成。
