title: Acute application of antioxidants protects against hyperoxia-induced reduction of plasma nitrite concentration.
abstract: We investigated the effects of acute intake of antioxidants on hyperoxia-induced oxidative stress, reduction of plasma nitrite and change in arterial stiffness. Twelve healthy males randomly consumed either placebo or an oral antioxidant cocktail (vitamin C, 1000 mg; vitamin E, 600 IU; alpha-lipoic acid, 600 mg). Every therapy was consumed once, a week apart, in a cross-over design, 30 min before the experiment. The volunteers breathed 100% normobaric oxygen between 30th and 60th min of 1-h study protocol. Plasma levels of nitrite, lipid peroxides (LOOH) and vitamin C, arterial stiffness (indicated by augmentation index, AIx) and arterial oxygen (Ptc O2 ) pressure were measured before and after hyperoxia. Exposure to oxygen caused a similar increase of Ptc O2 in both placebo and antioxidants groups, confirming comparable exposure to hyperoxia (438 ± 100 versus 455 ± 83 mm Hg). Vitamin C was increased in the antioxidants group confirming successful application of antioxidants (69 ± 14 versus 57 ± 15 μm). Hyperoxia resulted in increased AIx and LOOH and decreased nitrite in placebo (-32 ± 11 versus -47 ± 13%, 72 ± 7 versus 62 ± 6 μm H2 O2 and 758 ± 184 versus 920 ± 191 nm, respectively), but not in the antioxidants group (-42 ± 13 versus -50 ± 13%, 64 ± 9 versus 61 ± 8 μm H2 O2 and 847 ± 156 versus 936 ± 201 nm, respectively). The acute intake of selected antioxidants was effective in preserving bioavailabity of ˙NO and vascular function, against hyperoxia-induced oxidative stress.
authors.affiliation: Department of Internal Medicine, University Hospital Split, Split, Croatia.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Vucinovic
authors.affiliation: Department of Internal Medicine, University Hospital Split, Split, Croatia.
authors.forename: Darko
authors.initials: D
authors.lastname: Duplancic
authors.affiliation: Department of Pharmacology, University of Split School of Medicine, Split, Croatia.
authors.forename: Ana
authors.initials: A
authors.lastname: Seselja-Perisin
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry and Technology, University of Split, Split, Croatia.
authors.forename: Lea
authors.initials: L
authors.lastname: Kukoc-Modun
authors.affiliation: Department of Pharmacology, University of Split School of Medicine, Split, Croatia.
authors.forename: Grgo
authors.initials: G
authors.lastname: Gunjaca
authors.affiliation: Department of Internal Medicine, University Hospital Split, Split, Croatia.
authors.forename: Maja
authors.initials: M
authors.lastname: Radman
authors.affiliation: Department of Internal Medicine, University Hospital Split, Split, Croatia.
authors.forename: Jonatan
authors.initials: J
authors.lastname: Vukovic
authors.affiliation: Institute of Clinical Pharmacology, Hannover Medical School, Hannover, Germany.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tsikas
authors.affiliation: Department of Otorhinolaryngology, University Hospital Split, Split, Croatia.
authors.forename: Kolja
authors.initials: K
authors.lastname: Poljak
authors.affiliation: Department of Pharmacology, University of Split School of Medicine, Split, Croatia.
authors.forename: Darko
authors.initials: D
authors.lastname: Modun
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage*; D015536:Down-Regulation / Q000187:drug effects; D006801:Humans; D018496:Hyperoxia / Q000097:blood* / Q000517:prevention & control*; D008297:Male; D009573:Nitrites / Q000097:blood*; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000097:blood; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000975:Antioxidants; D009573:Nitrites; D017382:Reactive Oxygen Species; D010100:Oxygen
keywords: arterial stiffness; nitric oxide; oxygen; vasoconstriction; vitamin C