PT  - JOURNAL ARTICLE
AU  - K Alving
AU  - E Weitzberg
AU  - JM Lundberg
TI  - Increased amount of nitric oxide in exhaled air of asthmatics
AID  - 10.1183/09031936.93.06091368
DP  - 1993 Oct 01
TA  - European Respiratory Journal
PG  - 1368--1370
VI  - 6
IP  - 9
4099  - http://erj.ersjournals.com/content/6/9/1368.short
4100  - http://erj.ersjournals.com/content/6/9/1368.full
SO  - Eur Respir J1993 Oct 01; 6
AB  - The presence of nitric oxide (NO) in the exhaled air of humans has recently been described. We wanted to assess at what level exhaled NO originates in normal airways, and to determine whether airway inflammation induces changes in the levels of exhaled NO. Exhaled NO was continuously measured by chemiluminescence technique during normal tidal breathing through the nose or mouth, with a detection limit of 1 part per billion (ppb). Twelve control subjects were compared to eight patients with mild atopic asthma and rhinitis caused by occupational allergen. In control subjects, the major part of NO in exhaled air (up to 30 ppb) seemed to originate in the nasal airways, with only minor contribution from the lower airways and the oral cavity. However, in mild asthmatics, the level of exhaled NO during oral breathing, indicating the involvement of the lower airways, was increased 2-3 fold. Since increased production of NO in the lower airways may involve activated macrophages or neutrophils, we suggest that exhaled NO may be used to instantly monitor ongoing bronchial inflammation, at least when involving inducible NO synthase.