Effect of electron affinic hypoxic cell sensitizers on the radiolytic depletion of oxygen in mammalian cells irradiated at ultrahigh dose rates

Journal Article · Mon Mar 01 04:00:00 EST 1982 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(82)90653-8· OSTI ID:7067138

Michaels, H B

When CHO cells are equilibrated with a low level of oxygen (e.g. 0.4% O/sub 2/) and irradiated with single 3 ns pulses of electrons, a breaking survival curve is observed. This effect is believed to be the result of radiolytic oxygen depletion and can be prevented by the presence of a relatively low concentraton of hypoxic cell radiosensitizer. This prevention of the breaking survival curve has been observed for 2- and 5-nitroimidazoles, nitrofurans, and diamide. It is hypothesized that the sensitizer acts by competing wth oxygen for the radiation-induced intracellular oxygen-binding species, perhaps a hydrated electron adduct, leaving oxygen free to participate in radiosensitization reactions during the lifetime of the oxygen-sensitive radiation-induced target sites for lethal damage, probably DNA radicals produced by hydroxyl radical attack. The proposed role of the sensitizer in the interference with oxygen depletion is a transient phenomenon, occuring on the microsecond to millisecond time scale.

• Research Organization: Harvard Medical School, Boston, MA
• OSTI ID: 7067138
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 8:3/4; ISSN IOBPD
• Country of Publication: United States
• Language: English

Related Subjects

560121* -- Radiation Effects on Cells-- External Source-- (-1987)
560301 -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZOLES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL CULTURES
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
CONNECTIVE TISSUE CELLS
DECOMPOSITION
DOSE RATES
DRUGS
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FIBROBLASTS
FURANS
HAMSTERS
HETEROCYCLIC COMPOUNDS
IMIDAZOLES
LEPTONS
MAMMALS
NITRO COMPOUNDS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXYGEN
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOINDUCTION
RADIOLYSIS
RADIOSENSITIVITY EFFECTS
RADIOSENSITIZERS
RODENTS
SOMATIC CELLS
SURVIVAL CURVES
VERTEBRATES