Title5-nitro-gamma-tocopherol increases in human plasma exposed to cigarette smoke in vitro and in vivo.
Publication TypeJournal Article
Year of Publication2003
AuthorsLeonard SW, Bruno RS, Paterson E, Schock BC, Atkinson J, Bray TM, Cross CE, Traber MG
JournalFree Radic Biol Med
Date Published2003 Dec 15
Keywordsgamma-Tocopherol, Humans, In Vitro Techniques, Reproducibility of Results, Sensitivity and Specificity, Smoking

We hypothesized that the high concentrations of reactive nitrogen species in cigarette smoke and the known stimulatory effects of cigarette smoke on the inflammatory immune systems would lead to the formation of 5-nitro-gamma-tocopherol (NGT). In order to assess gamma-tocopherol nitration, human plasma was exposed in vitro to gas phase cigarette smoke (GPCS) or air for up to 6 h. A liquid chromatography-mass spectrometry (LC-MS) method was developed to quantitate NGT. Detector response was linear from 0.1 to 3 pmol NGT, with a detection limit of 20 fmol. After a 1 h lag time, 6 h plasma exposure to GPCS depleted approximately 75% of alpha-T, approximately 60% of gamma-T and increased NGT from 3 to 134 nmol/l. The increase in NGT accounted for approximately 20% of the gamma-T decrease. NGT also correlated (R2 = 0.9043) with nitrate concentrations in GPCS-exposed plasma. The physiologic relevance of NGT was evaluated in a group of healthy humans. Smokers (n = 15) had plasma NGT concentrations double those of nonsmokers (n = 19), regardless of corrections using lipids or gamma-T; plasma alpha-T and gamma-T concentrations were similar between the groups. Our results show that LC-MS can be successfully used for NGT quantitation in biologic samples. Importantly, NGT in smokers' plasma suggests that cigarette smoking causes increased nitrosative stress.

Alternate JournalFree Radic. Biol. Med.
PubMed ID14680679
Grant ListR01 DK059576 / DK / NIDDK NIH HHS / United States
R01 DK059576-01 / DK / NIDDK NIH HHS / United States
DK59576 / DK / NIDDK NIH HHS / United States