title: Urinary thromboxane, prostacyclin, cortisol, and 8-hydroxy-2'-deoxyguanosine in nonsmokers exposed and not exposed to environmental tobacco smoke.
abstract: This study tested the hypotheses that (1) increased platelet aggregation, as measured by 2,3-dinor-thromboxane B(2) (Tx-M) and 2,3-dinor-6-keto-prostaglandin F(1alpha) (PGI-M), and (2) increased oxidative stress, as measured by 8-Hydroxy-2'-deoxyguanosine (8-OHdG), would occur in ETS-exposed nonsmokers as compared with non-ETS-exposed nonsmokers. The concentrations of the stable urinary metabolites of thromboxane (Tx-M) and prostacyclin (PGI-M), cortisol and 8-OHdG were measured in a 24-h urine sample from 3 groups of subjects: 21 nonsmokers with minimal (15 min or less per day) ETS exposure (termed non-ETS-exposed), 22 nonsmokers with at least 5 h per day of ETS exposure (termed ETS-exposed), and 20 cigarette smokers who served as a positive control group. The self-reported levels of ETS exposure were verified by personal air monitors. As compared with either group of nonsmokers, cigarette smokers excreted significantly more urinary Tx-M. Non-ETS-exposed nonsmokers showed a statistically significantly higher level of urinary Tx-M over that seen in nonsmokers with considerably more ETS exposure. Urinary concentrations of PGI-M were marginally higher in the smokers and did not differ between the nonsmoker groups. Nonsmokers exposed to at least five h of ETS per day did not have significantly higher excretion of 8-OHdG than non-ETS-exposed nonsmokers. The results from this study suggest that platelet aggregation, as measured by the thromboxane metabolite Tx-M and prostacyclin metabolite PGI-M, is not associated with ETS exposure. Therefore, platelet aggregation is not a plausible or quantitatively consistent mechanism to explain the nonlinear dose-response hypothesis of cardiovascular disease and ETS exposure.
authors.affiliation: Research and Development, R. J. Reynolds Tobacco Company, Bowman Gray Technical Center, Winston-Salem, North Carolina 27102, USA. smithc4@rjrt.com
authors.forename: C J
authors.initials: CJ
authors.lastname: Smith
authors.forename: T H
authors.initials: TH
authors.lastname: Fischer
authors.forename: D L
authors.initials: DL
authors.lastname: Heavner
authors.forename: M A
authors.initials: MA
authors.lastname: Rumple
authors.forename: D L
authors.initials: DL
authors.lastname: Bowman
authors.forename: B G
authors.initials: BG
authors.lastname: Brown
authors.forename: M J
authors.initials: MJ
authors.lastname: Morton
authors.forename: D J
authors.initials: DJ
authors.lastname: Doolittle
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000393:Air Pollutants / Q000032:analysis; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000652:urine; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000652:urine*; D011464:Epoprostenol / Q000652:urine*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000652:urine*; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D010974:Platelet Aggregation / Q000502:physiology; D012907:Smoking / Q000097:blood*; D013931:Thromboxanes / Q000652:urine*; D014028:Tobacco Smoke Pollution / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D015415:Biomarkers; D013931:Thromboxanes; D014028:Tobacco Smoke Pollution; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003404:Creatinine; D011464:Epoprostenol; D003849:Deoxyguanosine; D006854:Hydrocortisone