title: Influence of antioxidants on the peroxidative swelling of mitochondria in vitro.
abstract: To clarify the role of prooxidative processes during in vitro swelling of freshly isolated rat liver mitochondria, the influence of different antioxidants and free-radical scavengers was tested. Ascorbate below 10 mmol/L without externally added Fe2+ acted as a prooxidant and enhanced swelling. Higher concentrations in the presence of Fe2+ showed antioxidant properties and a decrease in swelling and lipid peroxidation. Swelling was abolished by alpha-tocopherol and reduced to 50% by butylated hydroxytoluene. Glutathione supplementation decreased both swelling and lipid peroxidation. Oxidized glutathione caused swelling without any effect on peroxidation. Hydrogen peroxide, cumene hydroperoxide and t-butyl hydroperoxide caused progressive decreases in glutathione and reduced niacinamide coenzyme levels, suggesting prooxidative changes. Dithiothreitol was found to abolish this effect. Thus, antioxidants reverse superoxide-induced mitochondrial swelling and lipid peroxidation in vitro.
authors.affiliation: Ecotoxicology Section, Industrial Toxicology Research Centre, Lucknow, India.
authors.forename: P
authors.initials: P
authors.lastname: Kakkar
authors.forename: S
authors.initials: S
authors.lastname: Mehrotra
authors.forename: P N
authors.initials: PN
authors.lastname: Viswanathan
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008933:Mitochondrial Swelling / Q000187:drug effects; D009249:NADP / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D013481:Superoxides / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D013438:Sulfhydryl Compounds; D013481:Superoxides; D009249:NADP; D005979:Glutathione Peroxidase; D005978:Glutathione; D001205:Ascorbic Acid