Inhibition of oxygen-dependent radiation-induced damage by the nitroxide superoxide dismutase mimic, tempol

Journal Article · Thu Aug 15 00:00:00 EDT 1991 · Archives of Biochemistry and Biophysics; (United States)

DOI:https://doi.org/10.1016/0003-9861(91)90442-L· OSTI ID:5011748

Mitchell, J B; DeGraff, W; Kaufman, D; Krishna, M C; Samuni, A; Finkelstein, E; Ahn, M S; Hahn, S M; Gamson, J; Russo, A ^[1]

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1. Radiobiology Section, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States)

Stable nitroxide radicals have been previously shown to function as superoxide dismutase (SOD)2 mimics and to protect mammalian cells against superoxide and hydrogen peroxide-mediated oxidative stress. These unique characteristics suggested that nitroxides, such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol), might protect mammalian cells against ionizing radiation. Treating Chinese hamster cells under aerobic conditions with 5, 10, 50, and 100 mM Tempol 10 min prior to X-rays resulted in radiation protection factors of 1.25, 1.30, 2.1, and 2.5, respectively. However, the reduced form of Tempol afforded no protection. Tempol treatment under hypoxic conditions did not provide radioprotection. Aerobic X-ray protection by Tempol could not be attributed to the induction of intracellular hypoxia, increase in intracellular glutathione, or induction of intracellular SOD mRNA. Tempol thus represents a new class of non-thiol-containing radiation protectors, which may be useful in elucidating the mechanism(s) of radiation-induced cellular damage and may have broad applications in protecting against oxidative stress.

• OSTI ID: 5011748
• Journal Information: Archives of Biochemistry and Biophysics; (United States), Vol. 289:1; ISSN 0003-9861
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
BIOLOGICAL RADIATION EFFECTS
RADIOPROTECTIVE SUBSTANCES
PERFORMANCE TESTING
SUPEROXIDE DISMUTASE
RADIOSENSITIVITY EFFECTS
AEROBIC CONDITIONS
ANOXIA
CELL MEMBRANES
ELECTRON SPIN RESONANCE
GENE REGULATION
GLUTATHIONE
HAMSTERS
OXYGEN
RADIATION PROTECTION
X RADIATION
ANIMALS
BIOLOGICAL EFFECTS
CELL CONSTITUENTS
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENZYMES
IONIZING RADIATIONS
MAGNETIC RESONANCE
MAMMALS
MEMBRANES
NONMETALS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIATION EFFECTS
RADIATIONS
RESONANCE
RODENTS
TESTING
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture