The effect of EDTA and iron on the oxidation of hydroxyl radical scavenging agents and ethanol by rat liver microsomes.
Rat liver microsomes catalyzed an NADPH-dependent oxidation of dimethylsulfoxide, 2-keto-4-thiomethylbutyrate and ethanol. The addition of EDTA and iron (ferric)-EDTA increased the oxidation of the hydroxyl radical scavenging agents and ethanol. Unchelated iron had no effect; therefore, appropriately chelated iron is required to stimulate microsomal production of hydroxyl radicals. Catalase strongly inhibited control rates as well as EDTA or iron-EDTA stimulated rates of hydroxyl radical production whereas superoxide dismutase had no effect. The rate of ethanol oxidation was ten- to twenty-fold greater than the rate of oxidation of hydroxyl radical scavengers in the absence of EDTA or iron-EDTA, suggesting little contribution by hydroxyl radicals in the pathway of ethanol oxidation. In the presence of EDTA or iron-EDTA, the rate of ethanol oxidation increased, and under these conditions, hydroxyl radicals appear to play a more significant role in contributing toward the overall oxidation of ethanol.
D000818:Animals; D004121:Dimethyl Sulfoxide / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology*; D000431:Ethanol / Q000378:metabolism*; D007501:Iron / Q000494:pharmacology*; D008297:Male; D008715:Methionine / Q000031:analogs & derivatives* / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains
D000431:Ethanol; C014632:2-keto-4-methylthiobutyric acid; D004492:Edetic Acid; D008715:Methionine; D007501:Iron; D004121:Dimethyl Sulfoxide