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A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
Tobacco smoke and formation of N-(2-hydroxyethyl)valine in human hemoglobin
Roberto Bono1, Marco Vincenti, Umberto Saglia
1Department of Public Health and Microbiology, University of Torino, Torino, Italy. roberto.bono@unito.it
Abstract:
Human exposure to ethylene oxide (EtO) occurs mainly through inhalation of polluted air in occupational workplaces and/or via tobacco smoke. A significant biochemical reaction of EtO converts the terminal valine of hemoglobin into N-(2-hydroxyethyl)valine (HOEtVal). In the present study, the extent of HOEtVal formation in 360 healthy adults who were not occupationally exposed to EtO was measured with a gas chromatograph/mass spectrometer in the electron-capture negative chemical ionization mode. This parameter was correlated with smoking habits and urinary cotinine concentration, exhibiting a positive relationship between HOEtVal and the number of cigarettes smoked (r2 = .4416). Urinary cotinine measurements also correlated with HOEtVal and the number of cigarettes smoked. This positive correlation between urinary cotinine and HOEtVal (r2 = .3893) provides a new perspective on the early stages of carcinogenic processes.
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