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The involvement of transition metal ions on iron-dependent lipid peroxidation.
- Source :
- Archives of Toxicology; Apr2010, Vol. 84 Issue 4, p255-262, 8p, 2 Charts, 5 Graphs
- Publication Year :
- 2010
-
Abstract
- The metals iron (Fe) and copper (Cu) are considered trace elements, and the metals cobalt (Co) and nickel (Ni) are known as ultra-trace elements, considering their presence in low to very low quantity in humans. The biologic activity of these transition metals is associated with the presence of unpaired electrons that favor their participation in redox reactions. They are part of important enzymes involved in vital biologic processes. However, these transition metals become toxic to cells when they reach elevated tissue concentrations and produce cellular oxidative damage. Phospholipid liposomes (0.5 mg/ml, phosphatidylcholine (PC)/phosphatidylserine (PS), 60/40) were incubated for 60 min at 37°C with 25 μM of Fe<superscript>2+</superscript> in the absence and in the presence of Cu<superscript>2+</superscript>, Co<superscript>2+</superscript>, and Ni<superscript>2+</superscript> (0–100 μM) with and without the addition of hydrogen peroxide (H<subscript>2</subscript>O<subscript>2</subscript>, 5–50 μM). Iron-dependent lipid peroxidation in PC/PS liposomes was assessed by thiobarbituric acid-reactive substances (TBARS) production. Metal transition ions promoted lipid peroxidation by H<subscript>2</subscript>O<subscript>2</subscript> decomposition and direct homolysis of endogenous hydroperoxides. The Fe<superscript>2+</superscript>-H<subscript>2</subscript>O<subscript>2</subscript>-mediated lipid peroxidation takes place by a pseudo-second order process, and the Cu<superscript>2+</superscript>-mediated process by a pseudo-first order reaction. Co<superscript>2+</superscript> and Ni<superscript>2+</superscript> alone do not induce lipid peroxidation. Nevertheless, when they are combined with Fe<superscript>2+</superscript>, Fe<superscript>2+</superscript>-H<subscript>2</subscript>O<subscript>2</subscript>-mediated lipid peroxidation was stimulated in the presence of Ni<superscript>2+</superscript> and was inhibited in the presence of Co<superscript>2+</superscript>. The understanding of the effects of transition metal ions on phospholipids is relevant to the prevention of oxidative damage in biologic systems. [ABSTRACT FROM AUTHOR]
- Subjects :
- TRACE elements
IRON
COPPER
TRANSITION metals
HUMAN beings
Subjects
Details
- Language :
- English
- ISSN :
- 03405761
- Volume :
- 84
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Archives of Toxicology
- Publication Type :
- Academic Journal
- Accession number :
- 48645464
- Full Text :
- https://doi.org/10.1007/s00204-009-0487-y