title: Effects of Iron Overload on the Activity of Na,K-ATPase and Lipid Profile of the Human Erythrocyte Membrane.
abstract: Iron is an essential chemical element for human life. However, in some pathological conditions, such as hereditary hemochromatosis type 1 (HH1), iron overload induces the production of reactive oxygen species that may lead to lipid peroxidation and a change in the plasma-membrane lipid profile. In this study, we investigated whether iron overload interferes with the Na,K-ATPase activity of the plasma membrane by studying erythrocytes that were obtained from the whole blood of patients suffering from iron overload. Additionally, we treated erythrocytes of normal subjects with 0.8 mM H2O2 and 1 μM FeCl3 for 24 h. We then analyzed the lipid profile, lipid peroxidation and Na,K-ATPase activity of plasma membranes derived from these cells. Iron overload was more frequent in men (87.5%) than in women and was associated with an increase (446%) in lipid peroxidation, as indicated by the amount of the thiobarbituric acid reactive substances (TBARS) and an increase (327%) in the Na,K-ATPase activity in the plasma membrane of erythrocytes. Erythrocytes treated with 1 μM FeCl3 for 24 h showed an increase (132%) in the Na,K-ATPase activity but no change in the TBARS levels. Iron treatment also decreased the cholesterol and phospholipid content of the erythrocyte membranes and similar decreases were observed in iron overload patients. In contrast, erythrocytes treated with 0.8 mM H2O2 for 24 h showed no change in the measured parameters. These results indicate that erythrocytes from patients with iron overload exhibit higher Na,K-ATPase activity compared with normal subjects and that this effect is specifically associated with altered iron levels.
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Leilismara
authors.initials: L
authors.lastname: Sousa
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Israel J P
authors.initials: IJ
authors.lastname: Garcia
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Tamara G F
authors.initials: TG
authors.lastname: Costa
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Lilian N D
authors.initials: LN
authors.lastname: Silva
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Cristiane O
authors.initials: CO
authors.lastname: Renó
authors.affiliation: Laboratório de Biologia Molecular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Eneida S
authors.initials: ES
authors.lastname: Oliveira
authors.affiliation: Laboratório de Estudos em Neurociências das Epilepsias e Comorbidades, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Cristiane Q
authors.initials: CQ
authors.lastname: Tilelli
authors.affiliation: Laboratório de Biologia Molecular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Luciana L
authors.initials: LL
authors.lastname: Santos
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Vanessa F
authors.initials: VF
authors.lastname: Cortes
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Herica L
authors.initials: HL
authors.lastname: Santos
authors.affiliation: Laboratório de Bioquímica Celular, Universidade Federal de São João del Rei, Campus Centro-Oeste Dona Lindú, Av Sebastião Gonçalves Coelho 400, 35501-296, Divinópolis, Brazil.
authors.forename: Leandro A
authors.initials: LA
authors.lastname: Barbosa
mesh_terms: D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism*; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019190:Iron Overload / Q000097:blood / Q000201:enzymology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*
chemical_list: D008055:Lipids; D006861:Hydrogen Peroxide; D000254:Sodium-Potassium-Exchanging ATPase