title: In vivo nitrosation of morpholine in mice by inhaled NO2.
abstract: Groups of 3-5 mice were gavaged with aqueous solutions of 2 mg morpholine and immediately exposed to 2-50 ppm levels of NO2 in inhalation chambers for periods of up to 3 hours. After exposure, mice were frozen and pulverized in liquid nitrogen, and aliquots of frozen powder (congruent to 8 g) were extracted with cold 35% aqueous methanol and methylene chloride. Concentrated methylene chloride solutions were analyzed for N-nitrosomorpholine (NMOR), using gas chromatography with a Thermal Energy analyzer detector. NMOR levels in controls (exposed to NO2 alone, or dosed with morpholine without subsequent NO2 exposure) were less than 5 ng/mouse. NMOR yields in test mice were time-dependent with respect to duration of NO2 exposure and dose-dependent with respect to NO2 levels. These preliminary studies demonstrate the in vivo nitrosating potential of nitrogen oxides.
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009025:Morpholines / Q000378:metabolism*; D009585:Nitrogen Dioxide / Q000378:metabolism*; D009602:Nitrosamines / Q000378:metabolism*; D011437:Propylamines
chemical_list: D002273:Carcinogens; D009025:Morpholines; D009602:Nitrosamines; D011437:Propylamines; C013161:N-nitroso(di-n-propyl)amine; C002741:N-nitrosomorpholine; D009585:Nitrogen Dioxide