title: Modulation of sulfur dioxide-induced airways hyperresponsiveness in the conscious dog.
abstract: Brief exposure of conscious dogs to 30 ppm SO2 directly into the lungs resulted in a transient bronchoconstriction followed by a period of hypersensitivity to aerosolized methacholine and 5-hydroxytryptamine. The hypersensitivity was maximal 4 h after exposure to SO2. Both Wy-41,195 and disodium cromoglycate, two antiallergic drugs, inhibited the hypersensitivity to methacholine when administered just prior to methacholine challenge. Neither drug significantly influenced SO2-induced bronchospasm nor influenced methacholine hypersensitivity when administered just prior to SO2 exposure. Furthermore, Wy-41,195 was ineffective against methacholine hypersensitivity when administered orally for 4 days. SO2-induced airway hypersensitivity in the dog may thus provide a useful model for exploring mechanisms and pharmacologic modulation of bronchial hyperreactivity, a common feature of asthma.
mesh_terms: D000284:Administration, Oral; D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects; D000818:Animals; D001980:Bronchi / Q000187:drug effects / Q000503:physiopathology*; D003243:Consciousness; D004205:Cromolyn Sodium / Q000008:administration & dosage; D004285:Dogs; D008170:Lung Compliance / Q000187:drug effects; D008688:Methacholine Compounds / Q000494:pharmacology; D010072:Oxamic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives; D013458:Sulfur Dioxide / Q000494:pharmacology*
chemical_list: D000336:Aerosols; D008688:Methacholine Compounds; D013458:Sulfur Dioxide; C031308:(2-cyano-3-(methylamino)phenyl)oxoacetic acid; D004205:Cromolyn Sodium; D010072:Oxamic Acid