Antioxidant mechanisms in radiation injury and radioprotection
Oxygen is a very important factor in determining radiosensitivity because it enhances the damage to cellular components caused by ionizing radiation, although mechanisms involved in UV irradiation damage may overlap ionizing radiation effects. This paper emphasizes chemical protection against damage by ionizing radiation and predominantly against the effects of photons (and gamma radiation). It is possible that free radicals and their products induced by ionizing radiation can interact with reactive oxygen species formed during normal processes, such as superoxide and hydrogen peroxide produced by phagocytic cells or during enzymatic processes (xanthine oxidase activity; enzymes involved in eicosanoid metabolism). Metals such as iron can promote free radical damage, whereas some bound metals have radioprotectant potential, e.g., metallothionein and ceruloplasmin. There is increasing evidence that maintenance of the proper oxidation-reduction state of cells by the interconversion of the peptide sulfhydryl glutathione (GSH), and its disulfide form (GSSG) is a factor in the modulation of cellular radiosensitivity. Other protein and nonprotein sulfhydryls may also play a role both as targets of radiation damage and as protectors. Other physiological antioxidants (vitamin E) and antioxidant enzymes are interrelated in their function of controlling oxidative processes. This review concentrates on the role of oxygen, glutathione, and antioxidant enzymes in radiosensitivity and how exogenous chemicals interact with these endogenous factors.
- Research Organization:
- Armed Forces Radiobiology Research Inst., Bethesda, MD (USA)
- OSTI ID:
- 5814894
- Report Number(s):
- AD-A-205811/3/XAB; AFRRI-SR-88-47
- Resource Relation:
- Other Information: Pub. in Cellular Antioxidant Defense Mechanisms, Vol. 2, 163-189(1988)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ANTIOXIDANTS
ENZYMES
RADIOSENSITIVITY EFFECTS
GLUTATHIONE
OXYGEN
RADIATION INJURIES
RADIATION PROTECTION
HYDROGEN PEROXIDE
IONIZING RADIATIONS
IRON
IRRADIATION
METALS
PHAGOCYTES
PHOTONS
PROTEINS
RADIATION EFFECTS
RADICALS
TOLERANCE
ULTRAVIOLET RADIATION
VITAMIN E
ANIMAL CELLS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
DRUGS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
HYDROGEN COMPOUNDS
INJURIES
MASSLESS PARTICLES
NONMETALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDES
PEROXIDES
POLYPEPTIDES
RADIATIONS
RADIOPROTECTIVE SUBSTANCES
SOMATIC CELLS
TRANSITION ELEMENTS
VITAMINS
560150* - Radiation Effects on Animals