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Dietary nitrate (NO) supplementation has been shown to reduce resting blood pressure (BP). However, the mechanism(s) responsible for the reduction in BP has not been identified. Dietary NO supplementation may increase nitric oxide (NO) bioavailability and NO has been shown to inhibit sympathetic vasoconstriction. Therefore, the purpose of this study was to investigate the hypothesis that acute dietary NO supplementation would attenuate sympathetic vasoconstrictor responsiveness at rest and during exercise. In a double-blind randomized crossover design, 12 men performed a cold-pressor test (CPT) at rest and during moderate- and heavy-intensity alternate-leg knee-extension exercise after consumption of NO rich beetroot juice (~12.9 mmol NO) or a NO-depleted placebo (~0.13 mmol NO). Venous blood was sampled before and 2.5 hours after consumption of beetroot juice to measure total plasma nitrite/nitrate [NOx]. BP was measured by Finometer. Leg blood flow (LBF) was measured at the femoral artery via Doppler ultrasound and leg vascular conductance (LVC) was calculated. Sympathetic vasoconstrictor responsiveness was calculated as the percentage decrease in LVC in response to the CPT. Total plasma [NOx] was greater (p<0.001) in the NO compared to the placebo condition. However, blood pressure and plasma catecholamines were not different (p>0.05) between NO and placebo conditions at rest or during exercise. Sympathetic vasoconstrictor responsiveness (Δ % LVC) was not different (p>0.05) between NO and placebo conditions at rest or during moderate- and heavy-intensity exercise. These data demonstrate that acute dietary nitrate supplementation does not alter sympathetic vasoconstrictor responsiveness at rest and during exercise in young healthy males.
This article was published in the following journal.
Name: Journal of applied physiology (Bethesda, Md. : 1985)
Sympathetic nervous system (SNS) vasoconstriction is primarily achieved through the binding of norepinephrine (NE) to alpha (α)-adrenoreceptors. However, NE may also bind to beta (β)-adrenoreceptors...
Consumption of nitrate-rich beetroot juice can lower blood pressure in peripheral as well as central arteries and may exert additional hemodynamic benefits (e.g. reduced aortic wave reflections). The ...
In younger individuals, dietary nitrate supplementation has been shown to improve short-term vascular and muscle function. The role of higher habitual nitrate intake as part of a typical diet on muscl...
This double-blind, cross-over study examined in drug-naïve hypertensives the effects of a single-dose of dietary nitrate (beetroot juice, BRJ) on (i) office/ambulatory blood pressure (BP) and arteria...
The nitrate content of foods and water is highly variable, which has implications for the compilation of food-composition databases and assessment of dietary nitrate intake.
The main purpose of this study is to evaluate the effects of an acute dose of dietary nitrate in the form of beetroot juice on skeletal muscle blood flow in response to dynamic knee extens...
This study investigates the effect of dietary inorganic nitrate supplementation on 1) large elastic artery stiffness and hemodynamics and 2) cerebrovascular function in middle-aged and old...
Both acute ingestion (1-3 h) and chronic supplementation (3-30 days) with dietary nitrate has been shown to increase nitric oxide activity and, in some studies, to improve exercise economy...
This study investigates the influence of dietary nitrate supplementation on cardiovascular health and physical and cognitive performance in older adults. Participants will receive both a n...
Acute consumption of dietary nitrate (as beetroot juice) has been shown to decrease systemic blood pressure in multiple populations including newly diagnosed, untreated hypertensives. The ...
An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 188.8.131.52.
A dual inhibitor of both cyclooxygenase and lipoxygenase pathways. It exerts an anti-inflammatory effect by inhibiting the formation of prostaglandins and leukotrienes. The drug also enhances pulmonary hypoxic vasoconstriction and has a protective effect after myocardial ischemia.
An iron-sulfur and MOLYBDENUM containing FLAVOPROTEIN that catalyzes the oxidation of nitrite to nitrate. This enzyme can use either NAD or NADP as cofactors. It is a key enzyme that is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. This enzyme was formerly classified as EC 184.108.40.206.
An enzyme that catalyzes the oxidation of nitrite to nitrate in the presence of NADP+. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM. This enzyme was formerly classified as EC 220.127.116.11 and should not be confused with the enzyme NITRATE REDUCTASE (NAD(P)H).
An alpha-adrenergic agonist that causes prolonged peripheral vasoconstriction. It has little if any direct effect on the central nervous system.
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