title: The effect of oxygen on the delay in the initiation of DNA synthesis after irradiation.
abstract: The effect of oxygen on cell cycle delay by low doses of radiation on synchronized Harding Passey melanoma cells has been studied. Cells were irradiated 5 h after subculturing into fresh medium, and the delay before the start of S was measured. DNA synthesis was measured by frequent pulse labeling of the cells with radioactive thymidine to obtain the S-phase profile. The amount by which the irradiated cells S-phase profile had to be moved in time so that both the ascending and descending portions of the first S phase overlayed that of the controls was used as a measure of the delay. The magnitude of the delay was exponentially related to radiation dose and the effect of irradiating in the absence of oxygen was a dose multiplying factor of 2.5. This was similar to the oxygen effect on survival for cells irradiated under the same conditions.
authors.affiliation: Cancer Research Campaign, Gray Laboratory, Mount Vernon Hospital, Northwood, Middlesex, England.
authors.forename: D L
authors.initials: DL
authors.lastname: Dewey
authors.forename: K B
authors.initials: KB
authors.lastname: Williams
mesh_terms: D000818:Animals; D002460:Cell Line; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D007399:Interphase / Q000528:radiation effects*; D051379:Mice; D010100:Oxygen / Q000502:physiology*; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000528:radiation effects
chemical_list: D004273:DNA, Neoplasm; D010100:Oxygen