Radiosensitization of hypoxic mammalian cells by diamide. II. Studies of mechanism. [X Radiation]
Journal Article
·
· Radiat. Res.; (United States)
Diamide (diazenedicarboxylic acid bis(N,N'-dimethylamide)) radiosensitizes hypoxic Chinese hamster cells by decreasing the shoulder of the survival curve (at low concentrations) and increasing the slope (at high concentrations). We studied the mechanisms responsible for these two phenomena by irradiating cells under different conditions of temperature and substrate availability and measuring either their survival or DNA damage (chromosome aberrations and strand breaks). The results confirm that different mechanisms are responsible for the two effects. The effect on the shoulder appeared to be due to oxidation of endogenous nonprotein sulfhydryls and reduced pyridine nucleotides, compounds that would normally effect rapid chemical repair of certain (single-hit type) lesions. The slope effect, on the other hand, may have been due to reactions with DNA similar to those that have been described for the electron-affinic compounds. These results, together with the finding that hypoxic cells remained sensitized after the removal of diamide when they were irradiated in the cold, provide a useful model and a new experimental approach to the question of chemical radiosensitization.
- Research Organization:
- Univ. of California, San Francisco
- OSTI ID:
- 5112759
- Journal Information:
- Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 70:3; ISSN RAREA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synergistic chemical radiosensitization of hypoxic mammalian cells
The use of drugs which deplete intracellular glutathione in hypoxic cell radiosensitization
Polyfunctional radiosensitizers: VI. Dexamethasone inhibits shoulder modification by uncharged nitroxyl biradicals in mammalian cells irradiated in vitro
Journal Article
·
Wed Dec 31 23:00:00 EST 1975
· Int. J. Radiat. Oncol., Biol. Phys.; (United States)
·
OSTI ID:7118374
The use of drugs which deplete intracellular glutathione in hypoxic cell radiosensitization
Journal Article
·
Sun Feb 28 23:00:00 EST 1982
· Int. J. Radiat. Oncol., Biol. Phys.; (United States)
·
OSTI ID:6713764
Polyfunctional radiosensitizers: VI. Dexamethasone inhibits shoulder modification by uncharged nitroxyl biradicals in mammalian cells irradiated in vitro
Journal Article
·
Sat Oct 01 00:00:00 EDT 1983
· Radiat. Res.; (United States)
·
OSTI ID:5427927
Related Subjects
560121* -- Radiation Effects on Cells-- External Source-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMIDES
ANIMAL CELLS
ANIMALS
ANOXIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DNA
ELECTROMAGNETIC RADIATION
HAMSTERS
IONIZING RADIATIONS
MAMMALS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOSENSITIVITY EFFECTS
RODENTS
SULFHYDRYL RADICALS
SURVIVAL CURVES
TEMPERATURE DEPENDENCE
VERTEBRATES
X RADIATION
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMIDES
ANIMAL CELLS
ANIMALS
ANOXIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DNA
ELECTROMAGNETIC RADIATION
HAMSTERS
IONIZING RADIATIONS
MAMMALS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOSENSITIVITY EFFECTS
RODENTS
SULFHYDRYL RADICALS
SURVIVAL CURVES
TEMPERATURE DEPENDENCE
VERTEBRATES
X RADIATION