Abstract
Breath contains numerous kinds of chemical compounds derived not only from metabolites but exogenous chemicals. To develop a biogas diagnostic system, such exogenous chemicals compounds as cigarette smoking, air pollutions, ingestions of tablets and/or meals and so on must be considered. In the present study, we examined the effects of cigarette smoking on the biogas with low molecular weights. Nine hundreds and eighty eight subjects aged from 20 to 88 years old volunteered for the present study. Among them, current, ex-, and non-smokers were 20, 30 and 50%, respectively. Current smokers were asked to stop smoking after getting up in the morning. After tooth brushing and gargling, fasted subjects breathed purified artificial air via a mouthpiece in a sitting position for 12 min, during which exhaled air was collected via one-way valve into the Douglas bag. Minute ventilation volume and concentrations of carbon dioxide (CO2) and oxygen (O2) in exhaled air were monitored by a respiratory metabolic analyzer with the chemical sensors. Concentrations of hydrogen (H2), methane (CH4), carbon monoxide (CO), nitric oxide (NO) and nitric dioxide (NO2 = Nox–NO) in the bag were analyzed by gas chromatography and chemiluninescence methods. Significant increases in VCO and FCO of current smokers were observed in the heavy smokers, depending upon the pieces of cigarette smoking per day. On the other hand, VNO and FENO decreased in a dose-dependent manner. The other kinds of gases analyzed in the present study were not significantly affected by smoking. [J Physiol Sci. 2007;57 Suppl:S213]
