title: Microsomal lipid peroxidation: mechanisms of initiation. The role of iron and iron chelators.
abstract: The role of iron and iron chelators in the initiation of microsomal lipid peroxidation has been investigated. It is shown that an Fe3+ chelate in order to be able to initiate enzymically induced lipid peroxidation in rat liver microsomes has to fulfill three criteria: (a) reducibility by NADPH; (b) reactivity of the Fe2+ chelate with rat liver microsomes has to fulfill three criteria: (a) reducibility by NADPH; (b) reactivity of the Fe2+ chelate with O2; and (c) formation of a relatively stable perferryl radical. NADH can support lipid peroxidation in the presence of ADP-Fe3+ or oxalate-Fe3+ at rates comparable to those obtained with NADPH but requires 10 to 15 times higher concentrations of the Fe3+ chelates for maximal activity. The results are discussed in relation to earlier proposed mechanisms of microsomal lipid peroxidation.
authors.affiliation: Institute of Biological Chemistry, University of Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Ursini
authors.forename: M
authors.initials: M
authors.lastname: Maiorino
authors.forename: P
authors.initials: P
authors.lastname: Hochstein
authors.forename: L
authors.initials: L
authors.lastname: Ernster
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D004492:Edetic Acid / Q000494:pharmacology; D005609:Free Radicals; D007501:Iron / Q000378:metabolism / Q000494:pharmacology*; D007502:Iron Chelating Agents / Q000378:metabolism / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008314:Malonates / Q000494:pharmacology; D008862:Microsomes, Liver / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010070:Oxalates / Q000494:pharmacology; D019815:Oxalic Acid; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D010710:Phosphates / Q000494:pharmacology; D051381:Rats
chemical_list: D005609:Free Radicals; D007502:Iron Chelating Agents; D008314:Malonates; D010070:Oxalates; D010710:Phosphates; D009243:NAD; D009249:NADP; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D019815:Oxalic Acid; D004492:Edetic Acid; C030290:malonic acid; D007501:Iron; D010100:Oxygen