Paraquat and NADPH-dependent lipid peroxidation in lung microsomes
Since there exists some controversy in the literature as to whether paraquat augments microsomal lipid peroxidation via superoxide anion (O/sub 2//sup -/), the role of paraquat and active oxygen species in NADPH-dependent lung microsomal lipid peroxidation was investigated. Incubation of buffered aerobic mixture of bovine lung microsome and NADPH, in the presence or absence of exogenously added iron, resulted in a progressive formation of lipid peroxides whose accumulation could be followed at 535 nm as malondialdehyde. Paraquat strongly inhibited this lipid peroxidation, Thus, malondialydehyde formation was 50% inhibited by 4 X 10/sup -5/ M paraquat in the reaction mixture. The malondialdehyde color development by lipid peroxides was not affected by this concentration of paraquat. Lipid peroxidation was also strongly inhibited by singlet oxygen scavengers, e.g. dimethylfuran and diphenylfuran, and by catalase. Hydroxyl radical scavengers, e.g. mannitol, benzoate, and ethanol, had little effect in malondialydehyde production. Superoxide dismutase, which removes O/sub 2//sup -/ efficiently, did not inhibit malondialdehyde production by lung microsomes and rather enhanced its formation. A scheme in which paraquat and active O/sub 2/ species may be involved with microsomal lipid peroxidation is presented.
- Research Organization:
- Univ. of California, Davis
- OSTI ID:
- 5765034
- Journal Information:
- J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 256:19; ISSN JBCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study
Iron stimulation of chemiluminescence by microsomes and purified NADPH-cytochrome P-450 reductase
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOCHEMISTRY
BODY
CATTLE
CELL CONSTITUENTS
CELL CULTURES
CHEMISTRY
COWS
DATA
DOMESTIC ANIMALS
ELEMENTS
ENZYMES
EXPERIMENTAL DATA
HERBICIDES
HYDROXYL RADICALS
INFORMATION
INHIBITION
LIPIDS
LUNGS
MAMMALS
MICROSOMES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
OXYGEN
OXYGEN COMPOUNDS
PEROXIDES
PESTICIDES
RADICALS
RESPIRATORY SYSTEM
RESPONSE MODIFYING FACTORS
RUMINANTS
SPECTROPHOTOMETRY
SUPEROXIDE RADICALS
TOXICITY
UPTAKE
VERTEBRATES