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.

Keywords::

• Oxidative stress
• myocardio
• nitrosative stress
• respiratory chain
• retinol

Acknowledgements

This work was supported by grants from a Brazilian public agency, Conselho Nacional de Desenvolvimento CientÍfico e Tecnológico/National Council for Research and Development (CNPq) and from Rede Instituto Brasileiro de Neurociência/Net Brazilian Institute of Neuroscience (IBN-Net) - 01.06.0842–00. We would also like to thank the UFRGS, a public university from Brazil, where the study was performed .

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.