Induction of nitric oxide synthase in a model of allergic occupational asthma.
We have studied the induction of nitric oxide during late allergic responses, using a guinea pig model of trimellitic anhydride (TMA)-induced airway allergy. TMA is a low molecular weight chemical which can cause occupational asthma. The activity of nitric oxide synthase (NOS) was investigated by the detection of 3H-labeled citrulline formation from 3H-labeled arginine. In sensitized animals, challenge with TMA conjugated to guinea pigs albumin (TMA-GPSA) increased the activity of Ca(2+)-independent NOS (inducible NOS; iNOS) in lung and bronchial tissues at 15-17 h after challenge compared to nonsensitized animals. The induction of iNOS activity was associated with an associated with an increased level of nitrite, an end metabolite of the l-arginine-NO pathway, in bronchoalveolar lavage fluid. In contrast to iNOS, the activity of Ca(2+)-dependent NOS (constitutive NOS; cNOS) was not affected by the allergen challenge. These results demonstrate that iNOS in bronchial tissue is induced late after allergen challenge in sensitized guinea pig.
Yan
Z Q
ZQ
Department of Clinical Pharmacology, Gothenburg University, Sahlgrens Hospital, Sweden.
Hansson
G K
GK
Skoogh
B E
BE
Lötvall
J O
JO
D000485:Allergens; D000818:Animals; D001249:Asthma / Q000201:enzymology* / Q000276:immunology; D001980:Bronchi / Q000201:enzymology; D006168:Guinea Pigs; D007114:Immunization; D008168:Lung / Q000201:enzymology; D008297:Male; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D009784:Occupational Diseases / Q000201:enzymology*; D010796:Phthalic Anhydrides / Q000276:immunology
D000485:Allergens; D010796:Phthalic Anhydrides; C015559:trimellitic anhydride; D019001:Nitric Oxide Synthase