title: Effects of alpha-tocopherol on antioxidant enzyme activity in human fibroblast cultures.
abstract: The activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (Cat) were determined in human fibroblast cultures at four concentrations of exogenous alpha-tocopherol: 0.2, 2.5, 10 and 50 micrograms/ml of culture medium, or without alpha-tocopherol. Relationships between alpha-tocopherol levels and the activities of SOD and GPx were identified. The cellular alpha-tocopherol level correlated with GPx activity (p < or = 0.01) and inversely correlated with SOD activity (p < or = 0.003), but only when alpha-tocopherol was added to the culture medium. The variations in the cellular GPx/SOD ratio depended on the level of cellular alpha-tocopherol (p < or = 0.001). Furthermore, there was a strong inverse correlation between SOD and GPx activity (p < or = 0.0001). Cat activity did not correlate either with cellular alpha-tocopherol concentration, or with SOD or GPx activity. These results underline the complex interplay between alpha-tocopherol and other antioxidant systems in human fibroblast cultures.
authors.affiliation: Unité de Recherche génétique et mécanisme des maladies du foie de l'enfant INSERM U347, Hôpital de Bicêtre, France.
authors.forename: M
authors.initials: M
authors.lastname: Conti
authors.forename: M
authors.initials: M
authors.lastname: Couturier
authors.forename: A
authors.initials: A
authors.lastname: Lemonnier
authors.forename: F
authors.initials: F
authors.lastname: Lemonnier
mesh_terms: D002374:Catalase / Q000187:drug effects*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000187:drug effects*; D006801:Humans; D008054:Lipid Peroxides / Q000378:metabolism; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000187:drug effects*; D014810:Vitamin E / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D008054:Lipid Peroxides; D014810:Vitamin E; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase