title: A randomized controlled trial of inhaled L-arginine in patients with cystic fibrosis.
abstract: BACKGROUND
  Cystic fibrosis (CF) airways are nitric oxide (NO) deficient. We studied safety and efficacy of repeated inhalations of nebulized L-arginine, the substrate for NO synthase (NOS), in patients with CF.
  
  
  METHODS
  Double-blind, randomized, placebo-controlled crossover treatment trial of twice daily inhalation of 500 mg L-arginine for two weeks compared to inhalation of saline in 19 CF patients (ClinicalTrials.gov Identifier: NCT00405665).
  
  
  RESULTS
  L-arginine inhalation was well tolerated and resulted in a significant increase in exhaled NO. FEV1 increased by an average of 56 ml compared to -8 ml after saline solution; but this difference did not reach statistical significance. Sputum concentrations of L-ornithine, the product of arginase activity, increased significantly while the L-ornithine derived polyamines did not. There was no change in inflammatory markers in sputum.
  
  
  CONCLUSIONS
  Repeated inhalation of L-arginine in CF patients was safe and well tolerated. Inhaled L-arginine increased NO production without evidence for changes in airway inflammation.
authors: Division of Respiratory Medicine, Department of Pediatrics, the Hospital for Sick Children, University of Toronto, Toronto, Canada. hartmut.grasemann@sickkids.ca
authors: H
authors: H
authors: Grasemann
authors: E
authors: E
authors: Tullis
authors: F
authors: F
authors: Ratjen
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D001120:Arginine / Q000008:administration & dosage*; D018592:Cross-Over Studies; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis; D012129:Respiratory Function Tests; D055815:Young Adult
chemical_list: D009569:Nitric Oxide; D001120:Arginine
keywords: Airway inflammation; Clinical trial; Nitric oxide; Polyamines; l-Arginine