Austen K R, Jenner T J, O'Neill P, Fielden E M
Int J Radiat Biol Relat Stud Phys Chem Med. 1987 Aug;52(2):281-8. doi: 10.1080/09553008714551741.
Using a cellular fast-mixing technique, the time course of radiation sensitization of hypoxic, V79 cells by various concentrations of RSU-1069 (0.25-2.5 mmol dm-3) and misonidazole (2.5-50 mmol dm-3) have been studied to distinguish between fast chemical processes and the much slower biochemical responses to ionizing radiation and the monofunctional alkylating action of RSU-1069. Under conditions of equi-concentration, misonidazole and RSU-1069 show similar radiosensitizing efficiencies for pre-irradiation contact times up to 1 s. The values of the sensitizer enhancement ratio of approximately 1.5 for both 2-nitroimidazoles (2.5 mmol dm-3) is considerably less than that of 1.9-2.8 determined with misonidazole for a pre-irradiation contact time of 1 h under hypoxia. It is proposed that the enhanced radiosensitizing efficiency of RSU-1069 compared to that of misonidazole after long contact times involves, in part, the formation of 'sub-toxic' damage probably involving monofunctional and/or bifunctional action of RSU-1069 prior to irradiation.
采用细胞快速混合技术，研究了不同浓度的RSU - 1069（0.25 - 2.5 mmol dm⁻³）和灭滴灵（2.5 - 50 mmol dm⁻³）对缺氧V79细胞辐射增敏的时间进程，以区分快速化学过程与对电离辐射慢得多的生化反应以及RSU - 1069的单功能烷基化作用。在等浓度条件下，对于预照射接触时间长达1秒的情况，灭滴灵和RSU - 1069表现出相似的放射增敏效率。两种2 - 硝基咪唑（2.5 mmol dm⁻³）的增敏剂增强比约为1.5，远低于在缺氧条件下预照射接触时间为1小时时用灭滴灵测定的1.9 - 2.8。有人提出，与灭滴灵相比，RSU - 1069在长时间接触后放射增敏效率提高，部分原因可能是在照射前形成了可能涉及RSU - 1069单功能和/或双功能作用的“亚毒性”损伤。
