Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells

J Clin Invest. 1998 Sep 15;102(6):1200-7. doi: 10.1172/JCI2357.


It has been reported that exhaled nitric oxide levels are reduced in cystic fibrosis (CF) patients. We have examined the inducible isoform of nitric oxide synthase (iNOS) in the airways by immunostaining and found that iNOS is constitutively expressed in the airway epithelia of non-CF mouse and human tissues but essentially absent in the epithelium of CF airways. We explored potential consequences of lost iNOS expression and found that iNOS inhibition significantly increases mouse nasal trans-epithelial potential difference, and hindered the ability of excised mouse lungs to prevent growth of Pseudomonas aeruginosa. The absence of continuous nitric oxide production in epithelial cells of CF airways may play a role in two CF-associated characteristics: hyperabsorption of sodium and susceptibility to bacterial infections.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amiloride / pharmacology
  • Animals
  • Biological Transport
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / enzymology*
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics
  • Disease Models, Animal
  • Epithelial Cells / enzymology*
  • Humans
  • Immunity, Innate
  • Immunohistochemistry
  • Lung / cytology
  • Lung / enzymology
  • Mice
  • Mice, Mutant Strains
  • Nasal Mucosa / enzymology
  • Nitrates / analysis
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase / biosynthesis*
  • Nitric Oxide Synthase Type II
  • Nitrites / analysis
  • Pseudomonas Infections / complications
  • Respiratory System / enzymology*
  • Sodium / metabolism


  • CFTR protein, human
  • Nitrates
  • Nitrites
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Nitric Oxide
  • Amiloride
  • Sodium
  • NOS2 protein, human
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse