||Influence of Ozone and Nitrogen Dioxide on Hepatic Microsomal Enzymes in Mice.
Graham, J. A. ;
Miller, F. J. ;
Gardner, D. E. ;
Ward, R. ;
Menzel, D. B. ;
||Health Effects Research Lab., Research Triangle Park, NC. ;Northrop Services, Inc., Research Triangle Park, NC. ;Duke Univ., Durham, NC.
Nitrogen dioxide ;
Laboratory animals ;
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Since ambient concentrations of ozone and nitrogen dioxide increase drug-induced sleeping time in female mice, potential mechanisms were sought by investigating the effects of these gases on hepatic microsomal mixed-function oxidases in female CD-1 mice. Exposure to ozone did not change the concentration of cytochrome P-450 significantly. Aniline hydroxylase, but not aminopyrine N-demethylase or p-nitroanisole O-demethylase, activities were increased following exposure. Aniline hydroxylase activity was also increased after exposure. In these studies, ozone sometimes increased wet liver weight, and thus additional experiments were conducted. Exposure to ozone caused a lesser decrease in body weight than the decrease observed after a similar air exposure. Liver wet weights were elevated after ozone exposure. From these data, it is concluded that mechanisms other than those investigated are responsible for the effect of ozone and nitrogen dioxide on drug-induced sleeping time.