title: Nitrate as a precursor of the in-vivo formation of N-nitrosomorpholine in the stomach of guinea-pigs.
abstract: Reduction of nitrates to nitrites and formation of the carcinogen N-nitrosomorpholine (NMOR) was investigated in the stomach of guinea-pigs. A semisynthetic diet with nitrate plus morpholine was administered intragastrically after a 24-h fast; after treatment, the animals were killed and stomach nitrite contents were determined 6, 12, 18, 24 and 30 min after the treatment using a colorimetric method. NMOR content was determined 18 min after treatment with nitrate plus morpholine using gas chromatography-thermal energy analysis. Reduction of nitrates to nitrites in the stomach was observed that was sufficient to synthesize NMOR in guinea-pigs under the conditions of this experiment.
authors: Institute of Nutrition and Food Hygiene, City of Havana, Cuba.
authors: M O
authors: MO
authors: García Roché
authors: D
authors: D
authors: Ziebarth
mesh_terms: D000818:Animals; D001711:Biotransformation; D002273:Carcinogens / Q000096:biosynthesis*; D003124:Colorimetry; D005753:Gastric Mucosa / Q000378:metabolism*; D006168:Guinea Pigs; D009566:Nitrates / Q000378:metabolism* / Q000493:pharmacokinetics; D009602:Nitrosamines / Q000096:biosynthesis*
chemical_list: D002273:Carcinogens; D009566:Nitrates; D009602:Nitrosamines; C002741:N-nitrosomorpholine; C031618:sodium nitrate