title: Dusts causing pneumoconiosis generate .OH and produce hemolysis by acting as Fenton catalysts.
abstract: Silicates causing pneumoconiosis function as Fenton catalysts to generate hydroxyl radicals (.OH) when incubated with hydrogen peroxide and a reducing substance. In contrast, silicates which do not cause pneumoconiosis demonstrate no Fenton activity. Catalytic activity is decreased by pretreatment of silicates with the iron chelators deferoxamine or transferrin. Hemolysis from silicates is decreased by interventions which remove superoxide anion or hydrogen peroxide from the medium, or by pretreatment of dusts with iron chelators. Thus, asbestos and nonfibrous silicates may cause pneumoconiosis through a common oxidant mechanism by catalyzing production of toxic .OH radicals in the lung.
authors.affiliation: Pulmonary Division, University of Tennessee, Memphis 38163.
authors.forename: T P
authors.initials: TP
authors.lastname: Kennedy
authors.forename: R
authors.initials: R
authors.lastname: Dodson
authors.forename: N V
authors.initials: NV
authors.lastname: Rao
authors.forename: H
authors.initials: H
authors.lastname: Ky
authors.forename: C
authors.initials: C
authors.lastname: Hopkins
authors.forename: M
authors.initials: M
authors.lastname: Baser
authors.forename: E
authors.initials: E
authors.lastname: Tolley
authors.forename: J R
authors.initials: JR
authors.lastname: Hoidal
mesh_terms: D002384:Catalysis; D004391:Dust / Q000009:adverse effects*; D004910:Erythrocyte Membrane / Q000187:drug effects; D005609:Free Radicals; D006461:Hemolysis; D006801:Humans; D006861:Hydrogen Peroxide; D006878:Hydroxides / Q000096:biosynthesis*; D017665:Hydroxyl Radical; D007501:Iron; D011009:Pneumoconiosis / Q000097:blood / Q000209:etiology*; D012825:Silicon / Q000633:toxicity
chemical_list: D004391:Dust; C045076:Fenton's reagent; D005609:Free Radicals; D006878:Hydroxides; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron; D012825:Silicon