The effect of dietary nitrate on salivary, plasma, and urinary nitrate metabolism in humans.
Dietary nitrate is metabolized to nitrite by bacterial flora on the posterior surface of the tongue leading to increased salivary nitrite concentrations. In the acidic environment of the stomach, nitrite forms nitrous acid, a potent nitrating/nitrosating agent. The aim of this study was to examine the pharmacokinetics of dietary nitrate in relation to the formation of salivary, plasma, and urinary nitrite and nitrate in healthy subjects. A secondary aim was to determine whether dietary nitrate increases the formation of protein-bound 3-nitrotyrosine in plasma, and if dietary nitrate improves platelet function. The pharmacokinetic profile of urinary nitrate excretion indicates total clearance of consumed nitrate in a 24 h period. While urinary, salivary, and plasma nitrate concentrations increased between 4- and 7-fold, a significant increase in nitrite was only detected in saliva (7-fold). High dietary nitrate consumption does not cause a significant acute change in plasma concentrations of 3-nitrotyrosine or in platelet function.
Pannala
Ananth S
AS
Centre For Age-Related Diseases, GKT School of Biomedical Sciences, King's College London, London, UK.
Mani
Ali R
AR
Spencer
Jeremy P E
JP
Skinner
Vernon
V
Bruckdorfer
K Richard
KR
Moore
Kevin P
KP
Rice-Evans
Catherine A
CA
D000328:Adult; D001792:Blood Platelets / Q000378:metabolism; D001798:Blood Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009566:Nitrates / Q000493:pharmacokinetics*; D009573:Nitrites / Q000378:metabolism; D010974:Platelet Aggregation; D012463:Saliva / Q000378:metabolism*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood*
D001798:Blood Proteins; D009566:Nitrates; D009573:Nitrites; C002744:3-nitrotyrosine; D014443:Tyrosine