Urinary excretion of 3-methyladenine and 3-ethyladenine after controlled exposure to tobacco smoke

Publisher Website
Google Scholar
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 μg/m3 of nicotine. Carboxy-hemoglobin 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 μg/24 h). Smoking resulted in a significant increase (P < 0.01) in 3-MeAde excretion (13.6–14.8 μg/24 h); no change was observed in the average excretion of 3-MeAde by passive smokers (4.8–4.9 ug of 3-MeAde/24 h). 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.

This publication has 0 references indexed in Scilit: