Effect of alpha-tocopherol and alpha-tocopheryl quinone on the radiosensitivity of thiol-depleted mammalian cells
The effect of hypoxic cell radiosensitizers is increased when mammalian cells are depleted of endogenous glutathione by buthionine sulphoximine pre-treatment in vitro; a similar gain has not been observed in tumors in vivo despite evidence of glutathione depletion in vivo following buthionine sulphoximine treatment. However, concentrations of biological reducing agents other than glutathione were not measured in the in vivo experiments. Other reducing agents found in tumors include alpha-tocopherol, which reduces the sensitizing efficiency of nitro-aromatic sensitizers in thiol-depleted mammalian cells. These data suggest that the failure to observe large gains in misonidazole sensitizing efficiency in thiol-depleted tumors in vivo may be due, in part, to the presence of biological reducing agents such as alpha-tocopherol.
- Research Organization:
- Gray Laboratory of the Cancer Research Campaign, Northwood, Middlesex (England)
- OSTI ID:
- 6074159
- Journal Information:
- Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 16:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GLUTATHIONE
BIOSYNTHESIS
RADIOSENSITIZERS
EFFICIENCY
VITAMIN E
BIOLOGICAL EFFECTS
ANOXIA
HAMSTERS
METHIONINE
NEOPLASMS
SURVIVAL CURVES
AMINO ACIDS
ANIMALS
CARBOXYLIC ACIDS
DISEASES
DRUGS
LIPOTROPIC FACTORS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
RODENTS
SYNTHESIS
VERTEBRATES
VITAMINS
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture