Differential vascular reactivity responses acutely following ingestion of a nitrate rich red spinach extract.
Eur J Appl Physiol
; 116(11-12): 2267-2279, 2016 Dec.
Article
em En
| MEDLINE
| ID: mdl-27695978
ABSTRACT
INTRODUCTION:
Inorganic nitrate ingestion has been posited to affect arterial blood pressure and vascular function.PURPOSE:
We sought to determine the acute effect of a red spinach extract (RSE) high in inorganic nitrate on vascular reactivity 1-h after ingestion in peripheral conduit and resistance arteries.METHODS:
Fifteen (n = 15; males 8, females 7) apparently healthy subjects (aged 23.1 ± 3.3 years; BMI 27.2 ± 3.7 kg/m2) participated in this crossover design, double-blinded study. Subjects reported to the lab ≥2-h post-prandial and consumed RSE (1000 mg dose; ~90 mg nitrate) or placebo (PBO). Venipuncture was performed on three occasions baseline, 30-min post-ingestion and between 65 to 75-min post-ingestion. Baseline vascular measurements [i.e., calf venous occlusion plethysmography, brachial artery flow-mediated dilation (FMD)], 30-min of continuous blood pressure (BP) and heart rate (HR) analysis, and follow-up vascular measurements beginning at 40-min post-ingestion were also performed.RESULTS:
Humoral nitrate following RSE ingestion was significantly higher at 30- (+54 %; P = 0.039) and 65 to 75-min post-ingestion compared to baseline (+255 %, P < 0.001) and PBO at the same time points (P < 0.05). No significant changes in BP or HR occurred in either condition. Peak reactive hyperemia (RH) calf blood flow increased significantly (+13.7 %; P = 0.016) following RSE ingestion, whereas it decreased (-14.0 %; P = 0.008) following PBO ingestion. No significant differential FMD responses were detected (P > 0.05), though RH was decreased following the baseline measure in both conditions.CONCLUSIONS:
RSE significantly increased plasma nitrate 30-min post-ingestion, but acute microvascular (i.e., resistance vasculature) reactivity increases were isolated to the lower limb and no appreciable change in brachial artery FMD was observed.Palavras-chave
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Resistência Vascular
/
Vasodilatação
/
Pressão Sanguínea
/
Artéria Braquial
/
Spinacia oleracea
/
Nitratos
Tipo de estudo:
Clinical_trials
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Eur J Appl Physiol
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos