Effect of oxygen-radiosensitizer mixtures on the radiation response of Chinese hamster cells, line V-79-753B, in vitro

Journal Article · Tue Jul 01 04:00:00 EDT 1980 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575258· OSTI ID:5129568

Millar, B C; Fielden, E M; Steele, J J

The present data show that the maximum yield of single-strand breaks (ssb) in the cellular DNA of Chinese hamster cells V-79-753B is produced at a concentration of oxygen that produces an enhancement ratio for cell survival of 1.9. The relationship between the oxygen concentration and enhancement ratio for survival in this cell line is biphasic with a plateau at ER = 1.9 over the range of 1.5 to 7 ..mu..M O/sub 2/. For concetrations of oxygen below 1.5 ..mu..M a linear relationship between 1/D/sub 0/ and the initial yield of ssb is found. Electron affinic and free radical radiosensitizers operate by different mechanisms which are reflected at the level of ssb production; electron affinic compounds increase the yield of ssb in anoxia and in the presence of low concentrations of oxygen, whereas free radical radiosensitizers do not. The observation that TMPN can compete with oxygen or misonidazole in reactions that lead to changes in radiosensitivity but not ssb production indicates that the relationship between the two parameters must be casual and not casual.

• Research Organization: Inst. of Cancer Research, Sutton, England
• OSTI ID: 5129568
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 83:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560111 -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
CELL CULTURES
DNA
DOSE-RESPONSE RELATIONSHIPS
DOSES
DRUGS
ELEMENTS
HAMSTERS
IN VITRO
MAMMALS
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
OXYGEN
OXYGEN ENHANCEMENT RATIO
QUANTITY RATIO
RADIATION DOSES
RADIOINDUCTION
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RESPONSE MODIFYING FACTORS
RODENTS
STRAND BREAKS
SURVIVAL CURVES
VERTEBRATES