title: Nitric oxide attenuates platelet-activating factor induced nasal airway plasma extravasation in healthy subjects.
abstract: BACKGROUND
  Paranasal sinuses and the nose are important sources of nitric oxide (NO) in humans but the relevance of NO production to the control of nasal airway plasma exudation and its response to inflammatory mediators such as platelet-activating factor (PAF) in healthy subjects is not well known.
  
  
  METHODS
  In this study we aimed to evaluate the effect of the nitric oxide synthase (NOS) inhibitor NG L-arginine methyl ester (L-NAME) on nasal airway plasma extravasation at baseline and after an acute challenge with PAF that induces most symptoms of rhinitis. Eleven healthy subjects were enrolled in the study. Plasma extravasation in the nasal airway was assessed by measuring the albumin content of nasal lavage.
  
  
  RESULTS
  PAF challenge caused a significant increase in concentrations of albumin in the nasal lavage fluid (from 0.59 +/- 0.13 mg dL(-1) to 2.46 +/- 0.45 mg dL(-1)) after placebo. Pretreatment with L-NAME significantly prevented the increase of albumin in the nasal lavage fluid induced by PAF as compared to placebo (from 0.53 +/- 0.11 mg dL(-1) to 1.70 +/- 0.28 mg dL(-1); P < 0.005).
  
  
  CONCLUSIONS
  Topical administration of a NO inhibitor is able to attenuate the nasal airway plasma extravasation induced by PAF, suggesting that NO release in vivo is involved in the nasal response to PAF.
authors.affiliation: Pulmonary and Airway Vascular Unit, Department of Respiratory Medicine AO Monaldi, University Federico II, Naples, Italy. mauromaniscalco@hotmail.com
authors.forename: M
authors.initials: M
authors.lastname: Maniscalco
authors.forename: G
authors.initials: G
authors.lastname: Ferrara
authors.forename: L
authors.initials: L
authors.lastname: Carratù
authors.forename: M
authors.initials: M
authors.lastname: Sofia
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D000418:Albumins / Q000032:analysis; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000627:therapeutic use*; D017817:Nasal Lavage Fluid / Q000737:chemistry; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D010972:Platelet Activating Factor; D011292:Premedication; D012220:Rhinitis / Q000378:metabolism / Q000517:prevention & control*; D018709:Statistics, Nonparametric
chemical_list: D000418:Albumins; D004791:Enzyme Inhibitors; D010972:Platelet Activating Factor; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester