13CO2 gas is produced in the mouth and excreted without circulating through the lung when 13C-urea is given as a mouthwash - Urita, Y; Naruki, Y; Koyama, H; Nakatani, N; Nishino, S; Otsuka, Y (Nippon Shōkakibyō Gakkai zasshi, 1997)
Keywords: Adult; Carbon Dioxide - metabolism; Carbon Isotopes; Female; Humans; Male; Mouth; Mouthwashes; Urea - administration & dosage