Format

Send to

Choose Destination
See comment in PubMed Commons below
IARC Sci Publ. 1991;(105):571-8.

Inhibition of bacterially mediated N-nitrosation by ascorbate: therapeutic and mechanistic considerations.

Author information

1
Pathology Division, Centre for Applied Microbiology and Research, Salisbury, Wiltshire, UK.

Abstract

Ascorbate is known to inhibit the acid-catalysed N-nitrosation reactions of nitrite in the normally acid stomach, suggesting a useful therapeutic application of this compound to reduce exposure to the carcinogenic products of such reactions. However, in the achlorhydric stomach, which is particularly predisposed to cancer, increased exposure to endogenous N-nitroso compounds may result from bacterially catalysed reactions. The mechanism of these bacterially mediated reactions is only just beginning to be understood, and, indeed, more than one such mechanism may exist. Despite its usual lack of reactivity towards nitrite at neutral pH, ascorbate proved to be a potent inhibitor of the bacterially mediated (Pseudomonas aeruginosa) nitrosation of morpholine, competing with morpholine for the nitrosating agent elaborated by the bacteria from nitrite (the kinetics of the inhibition were classically competitive). This and other data, particularly with regard to the dependence of the bacterially mediated reaction on amine pKa, are discussed in relation to the potential mechanisms of these bacterially mediated reactions.

PMID:
1855920
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center