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.
Department of Clinical Pharmacology, Gothenburg University, Sahlgrens Hospital, Sweden.
Z Q
ZQ
Yan
G K
GK
Hansson
B E
BE
Skoogh
J O
JO
Lötvall
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