Repeated aeroallergen challenge induces lung dysfunction but not bronchial hyperresponsiveness in conscious guinea pigs.
Adult male Hartley-strain guinea pigs were sensitized by 10 min exposure to aerosolized 1% ovalbumin (OA; 10 mg/ml in normal saline containing 4% heat-killed B. pertussis vaccine and 0.02% antifoam B emulsion). One week after sensitization, animals were placed in an exposure chamber and challenged (nebulized OA 0.5%) until each animal showed labored breathing. Maximal exposure time was 10 min. Diphenhydramine (20 mg/kg, i.p.) was given 1 h before each OA challenge to protect the animals from bronchospasmic death. Antigen challenge was repeated twice a week for 2 weeks. The specific airway resistance (sR(aw)) changes in response to increasing concentrations of aerosolized acetylcholine (Ach) were determined. The data obtained in this study demonstrated that repeated antigen challenge produced a significant bronchial tone i.e. an increase in sR(aw) and a decline in specific airway conductance (sG(aw)) and failed to induce bronchial hyperreactivity to aerosolized acetylcholine (Ach) in conscious guinea pigs.
Chand
N
N
Wallace Laboratories, Division of Carter-Wallace Inc., Cranbury, NJ 08512.
Nolan
K
K
Diamantis
W
W
Sofia
R D
RD
D000109:Acetylcholine / Q000494:pharmacology; D000336:Aerosols; D000403:Airway Resistance / Q000187:drug effects; D000485:Allergens / Q000008:administration & dosage / Q000276:immunology*; D000818:Animals; D016535:Bronchial Hyperreactivity / Q000276:immunology / Q000503:physiopathology*; D004155:Diphenhydramine / Q000494:pharmacology; D004195:Disease Models, Animal; D006168:Guinea Pigs; D008171:Lung Diseases / Q000276:immunology / Q000503:physiopathology*; D008297:Male; D010047:Ovalbumin / Q000008:administration & dosage / Q000276:immunology; D012129:Respiratory Function Tests
D000336:Aerosols; D000485:Allergens; D004155:Diphenhydramine; D010047:Ovalbumin; D000109:Acetylcholine