You are here:
ENDOGENOUS FORMATION OF N-NITROSOMORPHOLINE IN MICE FROM 15NO2 BY INHALATION AND MORPHOLINE BY GAVAGE
Citation:
Stree, E., R. Sloane, J. Simmons, M. Moorman, AND K. Brunnemann. ENDOGENOUS FORMATION OF N-NITROSOMORPHOLINE IN MICE FROM 15NO2 BY INHALATION AND MORPHOLINE BY GAVAGE. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-95/148.
Description:
Male CD-1 mice were exposed to a nominal concentration of 20 ppm of 15N-nitrogen dioxide (15NO2) for 6 hr/day for 4 days and for 2 hr on the fifth day, and to 1g morpholine/kg body weight by gavage daily for 5 consecutive days. -nitrosomorpholine (NMOR) was found in whole mice, stomachs, skins with hair, and remains. he sum of individual tissue concentrations measured separately was 3421 ng/tissue, where the average skin weighed 4.3 g, the average stomach weighed 1.0 g, and the average remains weighed 22.2 g. The average whole mouse weighed 27.7 g and contained a total of 3903 ng of NMOR. he concentrations of NMOR was highest in the skin, next highest in the stomach, and lowest in the remains. owever, the total quantity of NMOR per tissue, while highest in the skin (83%), was next highest in the remains (14.8%), and lowest in the stomach (2.2%). C-MS analysis served to distinguish between the NMOR of 15NO2 origin and that of other origin. ll of the NMOR in the whole mouse homogenates was identified as 15NO2. n the stomach, 73% was identified as 14NMOR representing 1.6% of the total NMOR in the mouse, and 27% 15NMOR representing 0.6% of the total NMOR in the mouse. -nitrosamine formation in vivo is discussed as a possibly ongoing mammalian process.