Metabolism of N-nitrosodi-n-propylamine and N-nitrosodiallylamine by isolated rat hepatocytes.

Isolated rat hepatocytes were incubated with approximately equimolar amounts of N-nitrosodi-n-propylamine (NDPA) and N-nitrosodiallylamine (NDAA) in order to compare their metabolism. The principal metabolite of NDPA was N-nitroso-(2-hydroxypropyl)propylamine, which was present as a glucuronide. N-Nitroso-(3-hydroxypropyl)propylamine and N-nitrosopropyl-(carboxyethyl)amine were minor metabolites; no N-nitrosomethylpropyl-amine (NMPA) was detected. A single N-nitroso metabolite of NDAA was found and identified as N-nitroso-(2,3-dihydroxypropyl)allylamine. These data indicate that the allyl group of N-nitrosodiallylamine is readily oxidized by hepatocytes in vitro. It appears unlikely that N-nitrosomethylpropylamine is an intermediate in N-nitrosodi-n-propylamine metabolism.