title: Urinary excretion of 3-methyladenine and 3-ethyladenine after controlled exposure to tobacco smoke.
abstract: The urinary excretion of the DNA alkylation products 3-methyladenine (3-MeAde) and 3-ethyladenine (3-EtAde) after controlled exposure to cigarette smoke over a period of 4 days was determined by competitive radioimmunoassay after separation by HPLC. Twenty-four hour urine samples were collected from five smokers and five non-smokers. Days 1 and 3 (control days) were without smoking, on days 2 and 4 smokers consumed 24 cigarettes each within 8 h in an unventilated room (45 m3) in the presence of non-smokers. Average levels of carbon monoxide during exposure were 15-20 p.p.m., 2.8-3.5 mg/m3 of respirable suspended particles and 75-86 micrograms/m3 of nicotine. Carboxyhemoglobin levels increased by 9.0 and 1.8% in smokers and passive smokers respectively. On control days, urinary excretion of 3-MeAde was similar in smokers and non-smokers (4.7-6.2 micrograms/24 h). Smoking resulted in a significant increase (P < 0.01) in 3-MeAde excretion (13.6-14.8 micrograms/24 h); no change was observed in the average excretion of 3-MeAde by passive smokers (4.8-4.9 micrograms of 3-MeAde/24h). Baseline 3-EtAde excretion on control days was similar in smokers and passive smokers (13.7-32.8 ng/24 h). In smokers, the amount of urinary 3-EtAde was increased > 5-fold (119.3-138.5 ng/24 h) on smoking days; no effect on 3-EtAde excretion was observed on average in passive smokers (18.0-25.2 ng/24 h). The nature of the DNA-reactive agent(s) responsible for the increased urinary excretion of 3-alkyladenines, in particular of the sensitive indicator 3-EtAde, remains to be determined.
authors.affiliation: Institute of Cell Biology (Cancer Research), West German Cancer Center Essen, University of Essen Medical School, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kopplin
authors.forename: G
authors.initials: G
authors.lastname: Eberle-Adamkiewicz
authors.forename: K H
authors.initials: KH
authors.lastname: Glüsenkamp
authors.forename: P
authors.initials: P
authors.lastname: Nehls
authors.forename: U
authors.initials: U
authors.lastname: Kirstein
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000652:urine; D000328:Adult; D004781:Environmental Exposure; D006801:Humans; D008297:Male; D012907:Smoking / Q000378:metabolism*; D014028:Tobacco Smoke Pollution
chemical_list: D014028:Tobacco Smoke Pollution; C022595:3-ethyladenine; C025946:3-methyladenine; D000225:Adenine