The effects of two different doses of ultraviolet-A light exposure on nitric oxide metabolites and cardiorespiratory outcomes.
Eur J Appl Physiol
; 118(5): 1043-1052, 2018 May.
Article
em En
| MEDLINE
| ID: mdl-29516257
ABSTRACT
PURPOSE:
The present study investigated different doses of ultraviolet-A (UV-A) light on plasma nitric oxide metabolites and cardiorespiratory variables.METHODS:
Ten healthy male participants completed three experimental conditions, 7 days apart. Participants were exposed to no light (CON); 10 J cm2 (15 min) of UV-A light (UVA10) and 20 J cm2 (30 min) of UV-A light (UVA20) in a randomized order. Plasma nitrite [NO2-] and nitrate [NO3-] concentrations, blood pressure (BP), and heart rate (HR) were recorded before, immediately after exposure and 30 min post-exposure. Whole body oxygen utilization ([Formula see text]), resting metabolic rate (RMR) and skin temperature were recorded continuously.RESULTS:
None of the measured parameters changed significantly during CON (all P > 0.05). [Formula see text] and RMR were significantly reduced immediately after UVA10 (P < 0.05) despite no change in plasma [NO2-] (P > 0.05). Immediately after exposure to UVA20, plasma [NO2-] was higher (P = 0.014) and [Formula see text] and RMR tended to be lower compared to baseline (P = 0.06). There were no differences in [NO2-] or [Formula see text] at the 30 min time point in any condition. UV-A exposure did not alter systolic BP, diastolic BP or MAP (all P > 0.05). UV-A light did not alter plasma [NO3-] at any time point (all P > 0.05).CONCLUSIONS:
This study demonstrates that a UV-A dose of 20 J cm2 is necessary to increase plasma [NO2-] although a smaller dose is capable of reducing [Formula see text] and RMR at rest. Exposure to UV-A did not significantly reduce BP in this cohort of healthy adults. These data suggest that exposure to sunlight has a meaningful acute impact on metabolic function.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Consumo de Oxigênio
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Raios Ultravioleta
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Metabolismo Basal
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Pressão Sanguínea
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Frequência Cardíaca
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Nitratos
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Nitritos
Tipo de estudo:
Clinical_trials
Limite:
Adult
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Humans
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Male
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article