Mechanical properties of the lungs and experimental asthma in conscious allergic dogs.
Three allergic dogs were trained to swallow an esophageal balloon, breathe through a tracheostomy tube, and stand quietly in a wooden stall. The mechanical properties of their lungs were measured reproducibly over many months. Average values were: pulmonary resistance 1.33 cmH2O/l per s, static lung compliance 104 ml/cmH2O, and functional residual capacity 982 ml. In two dogs inhalation of histamine aerosol caused a 374% increase in resistance; inhalation of Ascaris suum aerosol caused a 307% increase in resistance. The increased resistance was associated with mild-to-moderate respiratory distress and slightly increased functional residual capacity. Aerosols of isoproterenol or atropine sulfate inhibited the increased resistance. We conclude that the conscious allergic dog is a suitable subject for the long-term study of asthma. Our present results are consistent with our earlier findings in anesthetized dogs, that a vagal reflex is involved in acute bronchomotor responses to inhalation of histamine as well as specific antigen.
D000403:Airway Resistance; D000485:Allergens / Q000494:pharmacology; D000818:Animals; D001200:Ascaris / Q000276:immunology; D001249:Asthma / Q000503:physiopathology*; D001980:Bronchi / Q000502:physiology; D003250:Constriction; D004195:Disease Models, Animal; D004285:Dogs; D006632:Histamine / Q000494:pharmacology; D008170:Lung Compliance; D008297:Male
D000485:Allergens; D006632:Histamine