title: Nitro-L-arginine inteferes with the cadmium reduction of nitrate/griess reaction method of measuring nitric oxide production.
abstract: Nitro-L-arginine is used as an inhibitor of nitric oxide synthase in many biological Systems. Nitric oxide (NO) is unstable and degrades to nitrite NO(2)- and nitrate NO(3)-. The colorimetric reaction of N0(2)- with Griess reagent is commonly used to measure NO(2)-. NO(3)- may be measured as NO(2)- following reduction by cadmium or cadmium/copper. We found that bradykinin increased the formation of NO(2)- by bovine coronary endothelial cells. Nitro-L-arginine further increased the formation of NO(2)-. This increase is due to the interference of nitro-L-arginine in determination of NO(3)- by the cadmium reduction to NO(2)- and Griess reagent reaction. Incubation of nitro-L-arginine with cadmium or cadmium/copper produced a product that reacts with Griess reagent to form a compound that has an absorption spectrum identical to the product formed by NO(2)- and Griess reagent. Caution must be exercised when using the NO(2)-/NO(3)- measurement by the Griess reaction to assess inhibition of nitric oxide synthase by nitro-L-arginine.
authors.affiliation: Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: K
authors.initials: K
authors.lastname: Nithipatikom
authors.forename: P F
authors.initials: PF
authors.lastname: Pratt
authors.forename: W B
authors.initials: WB
authors.lastname: Campbell
mesh_terms: D000818:Animals; D002104:Cadmium / Q000494:pharmacology*; D002417:Cattle; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D005029:Ethylenediamines; D016166:Free Radical Scavengers / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000378:metabolism; D019335:Nitroarginine / Q000378:metabolism / Q000494:pharmacology*; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet; D013424:Sulfanilamides
chemical_list: D004791:Enzyme Inhibitors; D005029:Ethylenediamines; D016166:Free Radical Scavengers; C095000:Griess reagent; D009566:Nitrates; D009573:Nitrites; D013424:Sulfanilamides; D002104:Cadmium; D019335:Nitroarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase