The metabolism of nitrosodi-n-propylamine, nitrosodiallylamine and nitrosodiethanolamine.

Nitrosodiallylamine has been reported to be non-carcinogenic in rats while nitrosodipropylamine and nitrosodiethanolamine are liver carcinogens. That nitrosodipropylamine is metabolized at the alpha-position by liver microsomes from Fischer-344 rats supports the widely held contention that such metabolism is responsible for the carcinogenicity of nitrosamines. Nitrosodiallylamine is also metabolized at the alpha-position by the same microsomal preparations. Thus, although alpha-oxidation may be responsible for the carcinogenicity of some nitrosamines, this mechanism alone cannot account for tumorigenicity. Nitrosodiethanolamine is not metabolized by rat liver microsomes, but is metabolized by hepatocytes for Fischer-344 rats. In this case, a mechanism other than the oxidation at the alpha-position may be responsible for the carcinogenic action.