Schäfer M, Schmitz C, Horneck G
DLR, Institute Aerospace Medicine, Linder Höhe, Köln, Germany.
Int J Radiat Biol. 1998 Aug;74(2):249-53. doi: 10.1080/095530098141636.
To study the sensitivity of two bacterial cell systems to photodynamic treatment and X-ray irradiation as part of a project to establish efficient procedures for waste water disinfection.
Stationary-phase cells of Deinococcus radiodurans (Gram-positive) and Escherichia coli (Gram-negative) were exposed to visible light in a buffer solution containing up to 5 microg/ml sensitizer rose bengal (RB) and to X-rays at dose rates of 32.8 Gy/min or 14.6 Gy/min, respectively.
Survival of both cell types decreased with increasing exposure time to visible light and increasing concentration of RB, and therefore with an increase in singlet oxygen production. Surprisingly, D. radiodurans, the most resistant cell system to ionizing radiation, was more sensitive to photodynamic treatment than E. coli by about a factor of 100.
The main target of singlet oxygen reaction is the cell membrane. The repair of such damage in D. radiodurans is less effective than in E. coli.
作为建立高效废水消毒程序项目的一部分，研究两种细菌细胞系统对光动力治疗和X射线照射的敏感性。
将耐辐射球菌（革兰氏阳性）和大肠杆菌（革兰氏阴性）的稳定期细胞分别置于含有高达5微克/毫升敏化剂孟加拉玫瑰红（RB）的缓冲溶液中暴露于可见光下，并分别以32.8戈瑞/分钟或14.6戈瑞/分钟的剂量率暴露于X射线下。
两种细胞类型的存活率均随可见光暴露时间的增加和RB浓度的增加而降低，因此随着单线态氧产生量的增加而降低。令人惊讶的是，耐辐射球菌作为对电离辐射最具抗性的细胞系统，对光动力治疗的敏感性比大肠杆菌高约100倍。
单线态氧反应的主要靶点是细胞膜。耐辐射球菌中此类损伤的修复效果不如大肠杆菌。
