LIPID PEROXIDATION IN THE PRESENCE OF IRON OXIDES

摘要

Exposure to iron oxides dusts may lead to lung cancers among exposed population. To evaluate the involvement of iron-containing particles in lipid peroxidation by production of reactive oxygen species, hematite, magnetite (iron oxides), and crocidolite (asbestos compound) were tested. The Peroxidation was followed by the evaluation of some degradation products of lino- lenic acid. In a buffered medium, magnetite is higher active than hematite. The addition of an iron chelator (EDTA) or of a reducing agent (ascorbate) in this medium enhances the activity of hematite and magnetite, and the combination of both EDTA and ascorbate increases their activity. Crocidolite is the most active whatever the medium. The appearance of the EDTA- iron--oxygen complexes related to the reactivity of these oxides is postulated. These results sug- gest that the oxidizing activity triggered by hematite and magnetite, in a medium containing an iron chelator and a reducing agent, may lead to damages in biological medium.