title: Non-invasive spatial visualization system of exhaled ethanol for real-time analysis of ALDH2 related alcohol metabolism.
abstract: A novel imaging system of ethanol in exhaled breath induced by acetaldehyde dehydrogenase (ALDH2)-related alcohol metabolism has been developed. The system provides an image of ethanol distribution as chemiluminescence (CL) on an enzyme-immobilized support. The spatiotemporal change of CL generated by ethanol in exhaled breath after oral administration of ethanol was detected by employing an electron multiplier CCD (EM-CCD) camera, illustrated and analyzed. Prior to measurement of standard gaseous ethanol and ethanol in exhaled breath, the system was optimized by investigating the enzyme-immobilized supports, concentration of substrate and pH condition of Tris-HCl buffer solution. The ethanol skin patch test, a simple method as an indicator of ALDH2, was performed on healthy volunteers. Breath samples of 5 volunteers with ALDH2 (+) and 5 volunteers with ALDH2 (-) were used for exhaled ethanol analysis. Concentration-time profiles of exhaled ethanol obtained from all volunteers were analyzed over a period of 120 min after oral administration of ethanol (0.4 g per kg body weight) in the form of beer which contains 5% of alcohol. The results obtained from the system showed that the peaks of exhaled ethanol concentrations appeared at 30 min, which was considered as a rapid ethanol absorption phase following first-order kinetics. Exhaled ethanol concentrations of volunteers with ALDH2 (+) were lower than volunteers with ALDH2 (-) and the digestion of ethanol in volunteers with ALDH2 (+) was faster than in volunteers with ALDH2 (-). The eliminations were analyzed to follow zero-order kinetics with a rate constant for each group.
authors.affiliation: Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo, 113-8549, Japan.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Eri
authors.initials: E
authors.lastname: Ando
authors.forename: Daishi
authors.initials: D
authors.lastname: Takahashi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Arakawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kudo
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saito
authors.forename: Kohji
authors.initials: K
authors.lastname: Mitsubayashi
mesh_terms: D000328:Adult; D000444:Aldehyde Dehydrogenase / Q000378:metabolism*; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D001944:Breath Tests / Q000379:methods*; D004800:Enzymes, Immobilized / Q000378:metabolism; D000431:Ethanol / Q000032:analysis* / Q000378:metabolism; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008163:Luminescent Measurements; D008297:Male
chemical_list: D004800:Enzymes, Immobilized; D000431:Ethanol; C096127:ALDH2 protein, human; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial