title: Hypobaric hypoxia-reoxygenation diminishes band 3 protein functions in human erythrocytes.
abstract: We have previously shown that subjects exposed to acute hypobaric hypoxia display an erythrocyte membrane protein band 3 with an increased susceptibility to proteolytic degradation. We suggested it was due to an oxidative damage of band 3. We now report that exposure to hypobaric hypoxia followed by reoxygenation affects protein band 3 functions such as anion transport and binding of glyceraldehyde-3P-dehydrogenase. Transport capacity was assessed with the fluorescent probe 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino] ethanesulfonate (NBD-taurine). Binding capacity was evaluated from the activity of the membrane-associated enzyme. Healthy young men were exposed for 20 min to hypobaric hypoxia, simulating an altitude of 4,500 m above sea level and after recompression band 3 function was assessed. An inhibition of band 3 anion transport function and a decrease in the binding of glyceraldehyde-3P-dehydrogenase to band 3 were observed. Evidence is given supporting the hypothesis that functional alteration of band 3 is due to its oxidative modification originated as a consequence of the exposure to hypobaric hypoxia and further reoxygenation.
authors.affiliation: Instituto de Química, Facultad de Ciencias Básicas y Matemáticas, Universidad Católica de Valparaíso, Valparaíso, Chile. ggonzale@ucv.cl
authors.forename: Gustavo
authors.initials: G
authors.lastname: González
authors.forename: Gloria
authors.initials: G
authors.lastname: Celedón
authors.forename: Mario
authors.initials: M
authors.lastname: Sandoval
authors.forename: Gabriela E
authors.initials: GE
authors.lastname: González
authors.forename: Verónica
authors.initials: V
authors.lastname: Ferrer
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Astete
authors.forename: Claus
authors.initials: C
authors.lastname: Behn
mesh_terms: D000328:Adult; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism*; D001274:Atmospheric Pressure; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000209:etiology*; D017136:Ion Transport / Q000187:drug effects; D008297:Male; D010069:Oxadiazoles / Q000493:pharmacokinetics; D010100:Oxygen / Q000494:pharmacology*; D013654:Taurine / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D005456:Fluorescent Dyes; C027027:NBD-taurine; D010069:Oxadiazoles; D013654:Taurine; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D010100:Oxygen