Inhibition of rat hepatic dimethylnitrosamine demethylase by cyclic and acyclic nitrosamines and secondary amines

Summary Inhibition of hepatic dimethylnitrosamine (DMN) metabolism by a variety of cyclic and acyclic nitrosamines was demonstrated. Nitrosoproline, a noncarcinogenic nitrosamine, behaved differently from the carcinogenic nitrosamines as an inhibitor for DMN-demethylase. Secondary amines corresponding to the nitrosamines inhibited DMN-demethylase in a manner similar to the nitrosamines.Acknowledgments. This work was supported by Public Health Service Grant 5-PO1-ES00597, Training Grant 1-732-ES07020, and Research Career Development Award 1-KO4-ES00033 (to M.C.A.) from the National Institute of Environmental Health Sciences. We are also grateful for support from Hoffmann-LaRoche Inc., Nutley, NJ.