title: Expression of nitric oxide synthases in leukocytes in nasal polyps.
abstract: BACKGROUND
  Nitric oxide (NO) has various roles in airway physiology and pathophysiology. Monitoring exhaled NO levels is increasingly common to measure airways inflammation and inhaled NO studied for its therapeutic value in premature infants and adult respiratory distress syndrome. NO is produced by 3 isoforms of NO synthase (NOS1, 2, 3), and each can play distinct and perhaps overlapping roles in the airways. However, the distribution, regulation, and functions of NOS in various cells in the upper airways, particularly in leukocytes, are incompletely understood.
  
  
  OBJECTIVE
  To characterize the expression of NOS isoforms in leukocytes in normal middle turbinate tissues (MT) and in inflammatory nasal tissue (nasal polyps, NP).
  
  
  METHODS
  Normal MT tissue was collected from surgical specimens that were to be discarded. The NP samples were from surgical tissue archives of 15 patients with chronic rhinosinusitis. Isoforms of NOS in cells were identified by double immunostaining using NOS isoform-specific and leukocyte-specific (mast cell, eosinophil, macrophage, neutrophil, or T cell) antibodies.
  
  
  RESULTS
  The proportion of total cells below the epithelium that were positive for each isoform of NOS was higher in NP than in MT. Each isoform of NOS was found in all leukocyte populations studied, and there were significant differences in the percentage of leukocytes expressing NOS isoforms between MT and NP.
  
  
  CONCLUSIONS
  All isoforms of NOS are expressed in leukocytes in MT and NP, and their expression varies among leukocyte types. Our data provide a basis to investigate the regulation, cell distribution, and distinct functions of NOS isoforms in normal and inflamed nasal tissues.
authors.affiliation: Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Tae Chul
authors.initials: TC
authors.lastname: Moon
authors.forename: Chris D
authors.initials: CD
authors.lastname: St Laurent
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Puttagunta
authors.forename: Kerri
authors.initials: K
authors.lastname: Chung
authors.forename: Erin
authors.initials: E
authors.lastname: Wright
authors.forename: Mamoru
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Moriyama
authors.forename: A Dean
authors.initials: AD
authors.lastname: Befus
mesh_terms: D000328:Adult; D004804:Eosinophils / Q000201:enzymology / Q000276:immunology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology; D007962:Leukocytes / Q000201:enzymology* / Q000276:immunology; D008264:Macrophages / Q000201:enzymology / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000201:enzymology / Q000276:immunology; D008875:Middle Aged; D009297:Nasal Mucosa / Q000201:enzymology / Q000276:immunology / Q000473:pathology; D009298:Nasal Polyps / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D009569:Nitric Oxide / Q000096:biosynthesis; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D014420:Turbinates / Q000201:enzymology
chemical_list: D009569:Nitric Oxide; C496320:NOS1 protein, human; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III