title: Endogenous nitric oxide in the upper airways of premature and term infants.
abstract: Concentrations of endogenous nitric oxide (NO) were measured in premature (n = 18) and term infants (n = 7). Nasal gas was aspirated continuously and after timed occlusions, 15 s and 60 s, by a fast-response chemiluminescence analyser. The sampling flow rate was 20 ml min-1. Typical NO recordings consisted of plateaux and postocclusive peaks. In term infants peak NO concentrations (60 s occlusion) were 2.71 +/- 0.44 parts per million (ppm) within 10 min after birth, increasing (p < 0.05) to 3.81 +/- 0.25 ppm at 4-7 d postnatally. Peak NO values (15 s occlusion) averaged 1.22 +/- 0.16 ppm in premature infants (postconceptional age 25-37 weeks, body weight 623-2844 g) and the NO concentrations increased significantly with postconceptional age (p < 0.05). Nasal excretion rate, estimated from plateau NO concentrations and sampling flow rate, was 0.10 +/- 0.01 nmol min-1 kg-1 in both groups. We conclude that premature and term newborn infants excrete considerable amounts of NO in the upper airways, with hitherto not fully known functions.
authors.affiliation: Division of Anaesthesia and Intensive Care, Karolinska Institute, Danderyd Hospital, Stockholm, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Schedin
authors.forename: M
authors.initials: M
authors.lastname: Norman
authors.forename: L E
authors.initials: LE
authors.lastname: Gustafsson
authors.forename: B
authors.initials: B
authors.lastname: Jonsson
authors.forename: C
authors.initials: C
authors.lastname: Frostell
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008137:Longitudinal Studies; D008168:Lung / Q000378:metabolism / Q000502:physiology; D008297:Male; D009297:Nasal Mucosa / Q000737:chemistry*; D009569:Nitric Oxide / Q000032:analysis* / Q000502:physiology
chemical_list: D009569:Nitric Oxide