Inhaled nitric oxide primes lung macrophages to produce reactive oxygen and nitrogen intermediates.
Inhaled nitric oxide is a selective pulmonary vasodilator used for the treatment of pulmonary hypertension. The potential adverse effects of inhaled nitric oxide are unknown and represent the focus of the present studies. Whereas inhalation of nitric oxide (10 to 100 ppm, 5 h) by Balb/c mice had no effect on the number or type of cells recovered from the lung, a dose-related increase in bronchoalveolar lavage protein was observed, suggesting that nitric oxide induces alveolar epithelial injury. To determine if this was associated with altered alveolar macrophage activity, we quantified production of reactive oxygen and nitrogen intermediates by these cells. Interferon-gamma, alone or in combination with lipopolysaccharide (LPS), induced expression of inducible nitric oxide synthase (iNOS) protein and nitric oxide production by alveolar macrophages. Cells from mice exposed to 20 to 100 ppm nitric oxide produced significantly more nitric oxide and expressed greater quantities of iNOS than cells from control animals. Superoxide anion production and peroxynitrite generation by alveolar macrophages were also increased after exposure of mice to nitric oxide. This was correlated with increased antinitrotyrosine antibody binding to macrophages in histologic sections. Taken together, these data demonstrate that inhaled nitric oxide primes lung macrophages to release reactive oxygen and nitrogen intermediates. Increased production of these mediators by macrophages following inhalation of nitric oxide may contribute to tissue injury.
Weinberger
B
B
Division of Neonatology, Department of Pediatrics and the Environmental and Occupational Health Sciences Institute, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School and Rutgers University, Piscataway, New Jersey, USA.
Fakhrzadeh
L
L
Heck
D E
DE
Laskin
J D
JD
Gardner
C R
CR
Laskin
D L
DL
D000280:Administration, Inhalation; D000818:Animals; D000906:Antibodies; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects; D007371:Interferon-gamma / Q000008:administration & dosage / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000008:administration & dosage / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D009584:Nitrogen / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism; D011506:Proteins / Q000032:analysis; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*
D000906:Antibodies; D008070:Lipopolysaccharides; D009566:Nitrates; D016877:Oxidants; D011506:Proteins; D017382:Reactive Oxygen Species; D014665:Vasodilator Agents; D013481:Superoxides; C039642:peroxynitric acid; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D009584:Nitrogen