Membrane lipid peroxidation: propagation and inhibition by antioxidants
Peroxidation studies in microsomes and liposomes were performed to evaluate the importance of the interaction between ascorbate and ..cap alpha..-tocopherol. The peroxidation of rat liver microsomes by FeSO/sub 4/ in the presence of ascorbate was delayed compared to when NADPH replaced ascorbate as the electron donor. To further investigate the cooperation between ascorbate and vitamin E, a liposomal system containing polyunsaturated phospholipids was used. Ascorbic acid alone (30 to 100 ..mu..M) delayed peroxidation by 20, and at higher concentrations, 60 minutes. Physiological levels of vitamin E decreased peroxidation at early times but was apparently consumed during incubation. Vitamin C and vitamin E together suppressed peroxidation at early times at approximately the sum of the individual inhibitions. At longer times, the mixture was more effective than the sum of both vitamins alone. The role of glutathione and the significance of its interaction with ascorbate were studied. Glutathione was able to reduce dehydroascorbic acid, but ascorbic acid was unable to reduce oxidized glutathione disulfide. Glutathione and ascorbic acid were oxidized by NO/sub 2/ in vitro. Pulmonary levels of glutathione and ascorbic acid in guinea pigs exposed to NO/sub 2/ were lowered. After the administration of diethyl maleate, the glutathione concentration was decreased, but the ascorbic acid concentration was unaffected. Simultaneous exposure further depressed glutathione concentration, but not the ascorbic acid concentration. (ERB)
- Research Organization:
- Rochester Univ., NY (USA)
- DOE Contract Number:
- AC02-76EV03490
- OSTI ID:
- 6498383
- Report Number(s):
- UR-3490-1952
- Resource Relation:
- Other Information: Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASCORBIC ACID
BIOLOGICAL EFFECTS
LIPOSOMES
OXIDATION
MICROSOMES
INHIBITION
VITAMIN E
REDOX POTENTIAL
CARBOXYLIC ACID ESTERS
GLUTATHIONE
NITROGEN DIOXIDE
STIMULATION
PEROXIDES
AMINO ACIDS
ANIMALS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHALCOGENIDES
CHELATING AGENTS
CHEMICAL REACTIONS
DIGESTIVE SYSTEM
DRUGS
ESTERS
GLANDS
HYDROGEN COMPOUNDS
IRON COMPOUNDS
LIPIDS
MAMMALS
MEMBRANES
MONOCARBOXYLIC ACIDS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
RESPIRATORY SYSTEM
RODENTS
SULFATES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
VITAMINS
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