Endogenous nitric oxide is present in the exhaled air of rabbits, guinea pigs and humans

Biochem Biophys Res Commun. 1991 Dec 16;181(2):852-7. doi: 10.1016/0006-291x(91)91268-h.


The presence of nitric oxide (NO) in the exhaled air of humans and of anaesthetized rabbits and guinea pigs was demonstrated by chemiluminescence, diazotization and mass spectrometry. This NO is endogenously produced in the lung by an NO synthase, since its generation in guinea pigs and rabbits was inhibited by N omega-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine, inhibitors of this enzyme. The effect of the inhibitors was reversed by the precursor of NO synthesis, L-arginine. Since NO is produced by normal vascular endothelium for the physiological regulation of blood flow and pressure and also by activated macrophages to contribute to non-specific immunity, our experiments suggest that NO may play both vascular regulatory and host defence roles in pulmonary physiology and pathophysiology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Oxidoreductases / antagonists & inhibitors
  • Animals
  • Arginine / analogs & derivatives
  • Arginine / pharmacology
  • Breath Tests*
  • Female
  • Guinea Pigs
  • Humans
  • Luminescent Measurements
  • Lung / metabolism
  • Male
  • Mass Spectrometry
  • NG-Nitroarginine Methyl Ester
  • Nitric Oxide / analysis*
  • Nitric Oxide Synthase
  • Rabbits
  • omega-N-Methylarginine


  • omega-N-Methylarginine
  • Nitric Oxide
  • Arginine
  • Nitric Oxide Synthase
  • Amino Acid Oxidoreductases
  • NG-Nitroarginine Methyl Ester