DNA damage in human endothelial cells after irradiation in anoxia.
Endothelial cells and fibroblasts have been reported to respond differently to oxidative stress. Both the effects of high oxygen tension and radiation involve the action of free radicals. DNA damage (single strand breaks, SSB, and double strand breaks, DSB) was assayed in human umbilical cord vein (HUV) cells and in Chinese hamster fibroblasts (V79) after irradiation under oxic or anoxic conditions. The cells were exposed to single doses in the range of 2-18 Gy of gamma-radiation from 60Co. Significantly more DNA damage was induced in the V79 cells than in the HUV cells. As a consequence, a higher oxygen enhancement ratio was obtained for the HUV cells (6.3) as compared to the V79 cells (2.8). The repair of SSB was slower in the HUV cells than in the V79 cells, irrespective of oxic state. For the higher doses, the damage remaining at 60 min after anoxic irradiation, i.e. DSB, was only detected in the V79 cells.
Rosander
K
K
Department of Oncology, University of Umeå, Sweden.
Zackrisson
B
B
D000818:Animals; D015687:Cell Hypoxia / Q000235:genetics*; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D004249:DNA Damage; D004730:Endothelium, Vascular / Q000528:radiation effects*; D005347:Fibroblasts / Q000528:radiation effects; D006801:Humans; D014471:Umbilical Veins