Nitrite and nitrate measurement by Griess reagent in human plasma: evaluation of interferences and standardization.
Nitrite and nitrate represent the final products of nitric oxide (NO) oxidation pathways, and their hematic concentrations are frequently assessed as an index of systemic NO production. However, their intake with food can influence their levels. Nitrite and nitrate could have a role by producing NO, because nitrite can release NO after reaction with deoxyhemoglobin and dietary nitrate can be reduced substantially to nitrite by commensal bacteria in the oral cavity. Different methods have been applied for nitrite/nitrate detection, with the most commonly used being the spectrophotometric assay based on the Griess reagent. However, a reference methodology for these determinations is still missing and many possible interferences have been reported. This chapter assesses how different experimental conditions can influence the results when detecting nitrite and nitrate in human plasma by the Griess assay and provides a simple method characterized by high reproducibility and minimized interferences by plasma constituents.
Giustarini
Daniela
D
Department of Evolutionary Biology, University of Siena, Siena, Italy.
Rossi
Ranieri
R
Milzani
Aldo
A
Dalle-Donne
Isabella
I
D003124:Colorimetry / Q000379:methods / Q000592:standards; D005029:Ethylenediamines / Q000592:standards; D016166:Free Radical Scavengers / Q000032:analysis / Q000097:blood / Q000592:standards; D006801:Humans; D009566:Nitrates / Q000032:analysis / Q000097:blood* / Q000592:standards; D009569:Nitric Oxide / Q000032:analysis / Q000097:blood / Q000592:standards; D009573:Nitrites / Q000032:analysis / Q000097:blood* / Q000592:standards; D012015:Reference Standards; D015203:Reproducibility of Results; D013424:Sulfanilamides / Q000592:standards
D005029:Ethylenediamines; D016166:Free Radical Scavengers; C095000:Griess reagent; D009566:Nitrates; D009573:Nitrites; D013424:Sulfanilamides; D009569:Nitric Oxide