title: Rate of nitric oxide release in the lung and factors influencing the concentration of exhaled nitric oxide.
abstract: The level of nitric oxide (NO) in exhaled air fluctuates in normal individuals depending on the physiological conditions. We evaluated the effects of duration of exhalation and breath-holding on the exhaled concentrations of NO in 16 normal human volunteers. Exhaled gas corresponding to vital capacity was collected in 6-liter Tedlar bags and analyzed by chemiluminescence. The NO concentration in exhaled gas increased significantly in proportion to the duration of exhalation [P = 0.009 +/- 0.011 (SD)] and was increased after breath-holding. There was no significant difference in the exhaled NO concentration among 10-s phases of a 30-s exhalation, as determined from multiple breath collections. The NO released from the airways is presumably unaffected by fluctuation of exhalation speed. The NO release rate, calculated from a single regression analysis between the NO concentration and the duration of exhalation, was 39 +/- 29 pmol/s, a value which was about fourfold greater in nine patients with bronchial asthma.
authors.affiliation: Second Department of Internal Medicine, Gunma University School of Medicine, Maebashi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Sakamaki
authors.forename: H
authors.initials: H
authors.lastname: Sumino
authors.forename: H
authors.initials: H
authors.lastname: Sakamoto
authors.forename: J
authors.initials: J
authors.lastname: Hoshino
authors.forename: H
authors.initials: H
authors.lastname: Masuda
authors.forename: Y
authors.initials: Y
authors.lastname: Sawada
authors.forename: M
authors.initials: M
authors.lastname: Mochida
authors.forename: Y
authors.initials: Y
authors.lastname: Ohyama
authors.forename: T
authors.initials: T
authors.lastname: Kurashina
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: Z
authors.initials: Z
authors.lastname: Ono
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000502:physiology; D005260:Female; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008722:Methods; D009569:Nitric Oxide / Q000378:metabolism*; D009994:Osmolar Concentration; D011650:Pulmonary Alveoli; D012119:Respiration; D012126:Respiratory Dead Space; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide; D009569:Nitric Oxide