DNA SINGLE-STRAND BREAKS INDUCED BY HEMATOPORPHYRIN PHOTOSENSITIZ-ER PLUS LASER IN MICE LEUKEMIA CELLS
- VernacularTitle:新光敏剂(PSD—007)-激光所致小鼠白血病细胞DNA链断裂损伤
- Author:
Nan LIU
;
Xiulong ZHENG
- Publication Type:Journal Article
- Keywords:
DNA,single stranded hematoporphyrin laser mice leukemia
- From:
Academic Journal of Second Military Medical University
1985;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
The induction of DNA single-strand breaks(ssb)by exposure to hematoporphyrin photosensitizer(PSD-007)followed by photoirradiation was observed in mice leukemia cells(L7712)in vitro. DNA ssb increased with the increase of dose of light in the rangeof 6.3-21 J/cm2 after treatment with 30?g/ml PSD-007. In lower concentration(1?g/ ml)of the drug,no ssb could be estimated after light exposure. Whan the concentration of PSD-007 was increased from 10 to 30?g/ml, however, the amount of ssb showed a rapid increase and tend to reach a plateau at 50ug/ml.comparing with ?-ray irradiation, we observed that PSD-007 could not increase the amount of ssb in cells irradiated with ?-ray and the most of ssb could be rejoined after incubation at 37℃ for 1 hour in the presence of PSD-007. However, DNA ssb induced by photosensitizer and light could not be repaired in post-photorad iated incubation. It is suggested that there exist some differences between the damages induced by photosensitization and by ioning radiation.From our experiment, we believe that DNA damage of cells is an early and critical event in photosensitization, which is different from that induced by y-ray irradiation.
