Godin CS, Crooks PA, Damani LA. N-methylation of phenylpyridines and bispyridyls as a potential toxication route: tissue distribution of azaheterocycle N-methyltransferase activity in the rabbit.
Toxicol Lett 1986;
34:217-22. [PMID:
3798480 DOI:
10.1016/0378-4274(86)90213-4]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The in vitro N-methylating capability of rabbit tissue cytosolic preparations, utilizing S-adenosyl-L-[methyl-3H]methionine as methyl donor, is described. Dialysed preparations from the lung, liver and kidney are capable of N-methylating 3- and 4-phenylpyridines and 3,3'- and 4,4'-bispyridyls; the corresponding 2-substituted derivatives are not substrates. With all the four substrates, azaheterocycle N-methyltransferase activity decreased in the order lung greater than kidney greater than liver; the activity in the lung was manifold greater than in the kidney and the liver. Azaheterocycle N-methyltransferase activity could not be detected in the brain cytosol under the enzyme assay conditions used. The production of N-methylpyridinium ion metabolites in the lung, from 4-phenylpyridine, 4,4'-bispyridyl and other pyridino-compounds present in tobacco smoke, may contribute to the observed pulmonary toxicity in tobacco users.
Collapse