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Abstract : |
Four normal horses were actively sensitized to Ascaris suum extract by repeated intratracheal injections. Three weeks after the last injection, conscious standing animals were challenged with a 10-2 dilution of A. suum extract administered as an aerosol for 3 min. Pulmonary mechanic and ventilation s were measured at 15, 30 and 60 min. after antigenic challenge. Horses responded to A. suum challenge with respiratory distress. Comparisons between baseline (obtained after saline inhalation) and post A. suum challenge values revealed significant increases in the non-elastic work of breathing, maximum change in transpulmonary pressure and pulmonary resistance. Dynamic compliance decreased (p<0.05). While tidal did not change, increases in respiration rate and minute were highly significant. Arterial blood samples were obtained 15 min. after the inhalation of A. suum and were compared with those obtained after saline inhalation. A significant decrease occurred in PaO2 while PaCO2, pH and HCO3 were not affected. These findings are consistent with those frequently observed in horses suffering from Chronic Obstructive Pulmonary Disease (COPD) as well as those seen in bronchial asthma in man. It is suggested that induced bronchospasm may be used as an experimental model of COPD. , Four normal horses were actively sensitized to Ascaris suum extract by repeated intratracheal injections. Three weeks after the last injection, conscious standing animals were challenged with a 10-2 dilution of A. suum extract administered as an aerosol for 3 min. Pulmonary mechanic and ventilation s were measured at 15, 30 and 60 min. after antigenic challenge. Horses responded to A. suum challenge with respiratory distress. Comparisons between baseline (obtained after saline inhalation) and post A. suum challenge values revealed significant increases in the non-elastic work of breathing, maximum change in transpulmonary pressure and pulmonary resistance. Dynamic compliance decreased (p<0.05). While tidal did not change, increases in respiration rate and minute were highly significant. Arterial blood samples were obtained 15 min. after the inhalation of A. suum and were compared with those obtained after saline inhalation. A significant decrease occurred in PaO2 while PaCO2, pH and HCO3 were not affected. These findings are consistent with those frequently observed in horses suffering from Chronic Obstructive Pulmonary Disease (COPD) as well as those seen in bronchial asthma in man. It is suggested that induced bronchospasm may be used as an experimental model of COPD., |
