Journal article
IRON AND FREE RADICAL OXIDATIONS IN CELL MEMBRANES
Cellular and molecular biology (Noisy-le-Grand, France), Vol.46(3), pp.657-662
05/2000
PMCID: PMC3800086
PMID: 10872752
Abstract
Brain tissue being rich in polyunsaturated fatty acids, is very susceptible to lipid peroxidation. Iron is well known to be an important initiator of free radical oxidations. We propose that the principal route to iron-mediated lipid peroxidations is
via
iron-oxygen complexes rather than the reaction of iron with hydrogen peroxide, the Fenton reaction. To test this hypothesis, we enriched leukemia cells (K-562 and L1210 cells) with docosahexaenoic acid (DHA) as a model for brain tissue, increasing the amount of DHA from approximately 3 mole % to 32 mole %. These cells were then subjected to ferrous iron and dioxygen to initiate lipid peroxidation in the presence or absence of hydrogen peroxide. Lipid-derived radicals were detected using EPR spin trapping with α-(4-pyridyl-1-oxide)-
N-t
-butylnitrone (POBN). As expected, lipid-derived radical formation increases with increasing cellular lipid unsaturation. Experiments with Desferal demonstrate that iron is required for the formation of lipid radicals from these cells. Addition of iron to DHA-enriched L1210 cells resulted in significant amounts of radical formation; radical formation increased with increasing amount of iron. However, the exposure of cells to hydrogen peroxide before the addition of ferrous iron did not increase cellular radical formation, but actually decreased spin adduct formation. These data suggest that iron-oxygen complexes are the primary route to the initiation of biological free radical oxidations. This model proposes a mechanism to explain how catalytic iron in brain tissue can be so destructive.
Details
- Title: Subtitle
- IRON AND FREE RADICAL OXIDATIONS IN CELL MEMBRANES
- Creators
- Freya Q SchaferSteven Yue QianGarry R Buettner
- Resource Type
- Journal article
- Publication Details
- Cellular and molecular biology (Noisy-le-Grand, France), Vol.46(3), pp.657-662
- PMID
- 10872752
- PMCID
- PMC3800086
- ISSN
- 0145-5680
- eISSN
- 1165-158X
- Grant note
- R01 CA081090 || CA / National Cancer Institute : NCI P01 CA066081 || CA / National Cancer Institute : NCI
- Language
- English
- Date published
- 05/2000
- Academic Unit
- Radiation Oncology
- Record Identifier
- 9984047990702771
Metrics
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