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  • Title: Recent findings on the metabolism of beta-hydroxyalkylnitrosamines.
    Author: Michejda CJ, Koepke SR, Kroeger-Koepke MB, Bosan W.
    Journal: IARC Sci Publ; 1987; (84):77-82. PubMed ID: 3316003.
    Abstract:
    beta-Hydroxynitrosamines appear to be refractory to alpha-oxidation, the common pathway of metabolism of simple dialkylnitrosamines. Some years ago, we postulated that nitrosamines bearing a hydroxyl in the beta position may be activated to alkylating agents by metabolic transformation to sulfate conjugates. Recent evidence has provided support for this hypothesis. A sulfate ester of N-nitroso(2-hydroxypropyl)(2-oxopropyl)amine (NHPOPA) has been found in the urine of hamsters treated with the nitrosamine. It has also been found that inhibition of sulfotransferases inhibited the development of DNA single-strand breaks in livers of rats treated with several beta-hydroxy-nitrosamines. Alkylation of rat liver DNA in vivo by N-nitroso(2-hydroxyethyl)methylamine (NHEMA) favoured methylation over 2-hydroxyethylation by a factor of 10. The methylation reaction was inhibited by sulfotransferase inhibitors. Thus, sulfation appears to be an important pathway for activation of beta-hydroxy-nitrosamines. There are, however, other pathways, such as the oxidation of the beta-hydroxyl group to a carbonyl, which may also result in the formation of electrophilic species capable of modifying cellular macromolecules.
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