title: Long-term vitamin A supplementation at therapeutic doses induces mitochondrial electrons transfer chain (METC) impairment and increased mitochondrial membrane-enriched fraction (MMEF) 3-nitrotyrosine on rat heart.
abstract: The aim of the present study was to compare electrons flux and oxidative/nitrosative stress parameters on the heart among rats supplemented with vitamin A and one not supplemented long-term. Vitamin A has important roles for the cardiovascular system as well as antioxidant properties. However, pro-oxidant properties have been reported. Male adult rats were treated with four different doses of retinyl palmitate (1000-9000 IU/Kg/day) or saline (control) for 28 days and the heart was removed for analysis. Electrons flux and oxidative/nitrosative stress parameters were evaluated and statistics were conducted with Anova one-way followed by Dunnet's post hoc and significance level of p<0.05. The supplementation induced increase on lipids/proteins oxidation and mitochondrial 3-nitrotyrosine content, an imbalance on enzymatic activity and a decrease on respiratory chain complexes activities. The results suggest that vitamin A induces oxidative/nitrosative stress and mitochondrial impairment on a cardiac level.
authors.affiliation: Center of Oxidative Stress Research, Professor Tuiskon Dick Departament of Biochemistry, Institute of Health Basic Sciences, Federal University of the Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. ricardorocha21@hotmail.com
authors.forename: Ricardo F
authors.initials: RF
authors.lastname: da Rocha
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: de Oliveira
authors.forename: Patrícia
authors.initials: P
authors.lastname: Schonhofen
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Schnorr
authors.forename: Felipe
authors.initials: F
authors.lastname: Dal Pizzol
authors.forename: José Cláudio F
authors.initials: JC
authors.lastname: Moreira
mesh_terms: D000818:Animals; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004579:Electron Transport / Q000187:drug effects; D042967:Electron Transport Complex I / Q000378:metabolism; D042963:Electron Transport Complex II / Q000378:metabolism; D014450:Electron Transport Complex III / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D006321:Heart / Q000187:drug effects*; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism*; D009206:Myocardium / Q000166:cytology*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D051381:Rats; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism; D014801:Vitamin A / Q000008:administration & dosage* / Q000009:adverse effects*
chemical_list: D014801:Vitamin A; C002744:3-nitrotyrosine; D014443:Tyrosine; D042963:Electron Transport Complex II; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III