Microsomal lipid peroxidation. I. Characterization of the role of iron and NADPH

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Mol. Pharmacol.; (United States)

OSTI ID:6122268

Kornbrust, D J; Mavis, R D

The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to depend on the presence of free ferrous iron. High concentrations of Fe/sup 2 +/ initiated microsomal lipid peroxidation at an initial rate which was independent of NADPH. With Fe/sup 3 +/, lower Fe/sup 2 +/ concentrations, or longer incubation times, NADPH stimulated microsomal lipid peroxidation and this stimulation was blocked by cytochrome c. NADPH did not induce peroxidation in the absence of iron, nor did ferric iron in the absence of NADPH. Thus the role of NADPH appears to be maintenance of iron in the reduced Fe/sup 2 +/ state. Complete chelation of iron by EDTA completely inhibited peroxidation. Preincubation of microsomes in the absence of iron did not enhance the rate of peroxidation upon subsequent addition of iron, suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of preformed hydroperoxides. Ascorbate stimulated iron-induced liposomal peroxidation but had no effect in the absence of iron.

• Research Organization: Univ. of Rochester, NY
• OSTI ID: 6122268
• Journal Information: Mol. Pharmacol.; (United States), Journal Name: Mol. Pharmacol.; (United States) Vol. 17; ISSN MOPMA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOCHEMISTRY
BODY
CATIONS
CELL CONSTITUENTS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
COENZYMES
CYTOCHROMES
DIGESTIVE SYSTEM
GLANDS
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
IONS
IRON COMPOUNDS
LIPIDS
LIVER
MAMMALS
MICROSOMES
NADP
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
OXIDATION
OXYGEN COMPOUNDS
PEROXIDES
PIGMENTS
RATS
RODENTS
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES