Biosynthesis of dimethylnitrosamine in dimethylamine-treated mice after exposure to nitrogen dioxide.
These studies demonstrate the nitrosating potential of NO2 in vivo in ICR mice. Groups of mice were gavaged with 2 mg dimethylamine (DMA) and exposed to NO2 at levels from 0.04 to 44.5 ppm for periods up to 4 hours. Mice were individually frozen and blended to a powder, aliquots of which were homogenized in ice-cold dicholoromethane and 35% aqueous methanol. Concentrates of organic extracts were analyzed or dimethylnitrosamine (DMN) by a Thermal Energy Analyzer with a gas chromatograph interface. Biosynthesis of DMN was dose- and time-dependent with relation to NO2 exposure, reaching a maximum yield of 60-70 ng/mouse (0.0035% DMA conversion) at 2 hours. DMN biosynthesis was inhibited by sodium ascorbate and, more effectively, by ammonium sulfamate.
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D004123:Dimethylamines / Q000378:metabolism*; D004128:Dimethylnitrosamine / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009585:Nitrogen Dioxide / Q000494:pharmacology*; D000644:Quaternary Ammonium Compounds; D013997:Time Factors
D004123:Dimethylamines; D000644:Quaternary Ammonium Compounds; D004128:Dimethylnitrosamine; D001205:Ascorbic Acid; D009585:Nitrogen Dioxide