title: Activated oxygen and mammalian nitrate biosynthesis.
abstract: The oxidation of NH3 to NO3- by rat liver in vitro is described. A xanthine-xanthine oxidase reaction also oxidized NH3 to NO3- when H2O2 was added. An in vivo inhibitor of superoxide dismutase enhanced the in vitro liver conversion of NH3 to NO3-. Thus, intracellular oxidation by activated oxygen likely represents the source of endogenously formed NO3- in mammals.
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000818:Animals; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008297:Male; D009566:Nitrates / Q000378:metabolism*; D010269:Paraquat / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013482:Superoxide Dismutase / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000494:pharmacology
chemical_list: D009566:Nitrates; D013481:Superoxides; D000641:Ammonia; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D010269:Paraquat