title: Re-evaluation of the effect of smoking on the methylation of N-terminal valine in haemoglobin.
abstract: In view of the established extrapulmonary cancer sites targeted by smoking a multiplicity of compounds and mechanisms might be involved. It has been debated that smoking caused increased incidence of N-methylvaline at the N-terminus of haemoglobin. Because this could indicate a relevance of methylating nitrosamines in tobacco smoke, data are presented from an industrial cohort of 35 smokers and 21 non-smokers repeatedly monitored between 1994 and 1999. In general, N-methylvaline adduct levels in haemoglobin of smokers were approximately 50% higher than those of non-smokers. The smoking-induced methylation of haemoglobin is likely to be caused by dimethylnitrosamine (N-nitroso-dimethylamine), a major nitrosamine in side-stream tobacco smoke. The biomonitoring data emphasise the potential value of N-methylvaline as a smoking-related biomarker and call for intensified research on tobacco smoke compounds that lead to macromolecular methylation processes.
authors.affiliation: Institut für Arbeitsphysiologie an der Universität Dortmund, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Thier
authors.forename: J
authors.initials: J
authors.lastname: Lewalter
authors.forename: S
authors.initials: S
authors.lastname: Selinski
authors.forename: H M
authors.initials: HM
authors.lastname: Bolt
mesh_terms: D015331:Cohort Studies; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008745:Methylation; D009602:Nitrosamines / Q000032:analysis; D012907:Smoking / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects* / Q000032:analysis; D014633:Valine / Q000378:metabolism*
chemical_list: D006454:Hemoglobins; D009602:Nitrosamines; D014028:Tobacco Smoke Pollution; D014633:Valine