title: Biotransformation of nitric oxide, nitrite and nitrate.
abstract: Biotransformation of NO, nitrite and nitrate was investigated in rats and mice in a 15NO inhalation experiment and intraperitoneal injection experiments of 15N-nitrite and 15N-nitrate, and the following results were obtained: (1) Rats were forced to inhale 15NO (145 ppm, 123 minutes) or were given an intraperitoneal injection of 15N-nitrite (2 mg animal-1 as 15N) or 15N-nitrate (2mg animal-1 as 15N), and determination of 15N recovery in urine was made up to 48 h later. The results were 55, 53 and 78% of the inhaled or injected 15N, respectively. (2) 15N-nitrate in the urine was converted into a 6-nitro derivative of 3,4-xylenol and its identification and quantitative determination were made by the GC-MS method. As to 15N-urea in the urine, identification and quantitative determination were made by the urease method. 15N was present in the urine of rats after 15NO inhalation in the form of NO3- and urea. 75 and 24% respectively. In the urine of rats injected with 15N-nitrite, about 20% of unidentified 15N-compounds not discovered in the inhalation experiment was found. The content of 15N-urea in the urine after injection with 15N-nitrate was lower than that after injection with 15N-nitrite. (3) When 15N-nitrite (0.617 mg animal-1 as 15N) was injected intraperitoneally in mice, 60.7, 7.8 and 0.3% of the injected 15N were found in the urine, feces and exhaled gas (NO, NO2 and NH3 in the gas were caught) up to 48 h after injection respectively, and 1.6% was found in the body 48 h after injection, but the remaining 30% of 15N could not be recovered.
mesh_terms: D000818:Animals; D001711:Biotransformation; D007274:Injections, Intraperitoneal; D008297:Male; D051379:Mice; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D009587:Nitrogen Isotopes; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D014508:Urea / Q000652:urine
chemical_list: D009566:Nitrates; D009573:Nitrites; D009587:Nitrogen Isotopes; D009569:Nitric Oxide; D014508:Urea