Glutathione delays varies as-tocopherol oxidation and subsequent lipid peroxidation in rat liver microsomes
A method has been developed for in vitro trace radiolabeling of rat liver microsomes with /sup 3/H-..cap alpha..-tocopherol (..cap alpha..T*) which allows virtually complete oxidation of the ..cap alpha..T* under oxidizing conditions. The supernatant of a 16,000 xg centrifugation of homogenized rat liver, containing the cytosolic rat liver vitamin E (VE) transfer protein, was incubated with an ethanolic solution of ..cap alpha..T* for 10 minutes at 37/sup 0/C. Labeled microsomes were collected in the washed 100,000 xg pellet. Microsomes were then incubated with 30 ..mu..M Fe/sup 2 +/ in an NADPH-generating system, and both production of malondialdehyde (MDA) (a product of lipid peroxidation) and oxidation of ..cap alpha..T* were monitored over a time course in the presence and absence of glutathione (GSH). The results indicate virtually complete oxidation of ..cap alpha..T* precedes significant membrane lipid peroxidation, and that addition of 5 mM GSH delays both ..cap alpha..T* oxidation and subsequent MDA production. This suggests that the previously observed VE-dependent heat labile inhibition of microsomal lipid peroxidation by GSH involves maintaining membrane levels of ..cap alpha..-tocopherol.
- Research Organization:
- Univ. of Rochester, NY
- DOE Contract Number:
- FG02-85ER60282
- OSTI ID:
- 7170655
- Report Number(s):
- CONF-8606151-; TRN: 86-039176
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GLUTATHIONE
BIOLOGICAL EFFECTS
LIPIDS
METABOLISM
MICROSOMES
LABELLING
VITAMIN E
ALDEHYDES
CELL MEMBRANES
CENTRIFUGATION
LIVER
NADP
RATS
TRITIUM COMPOUNDS
ANIMALS
BODY
CELL CONSTITUENTS
COENZYMES
DIGESTIVE SYSTEM
DRUGS
GLANDS
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
RODENTS
SEPARATION PROCESSES
VERTEBRATES
VITAMINS
550501* - Metabolism- Tracer Techniques