Experimental emphysema. Histologic changes and alterations in pulmonary circulation.

Detailed study of the pathogenesis of bullous emphysema has been hampered by lack of a suitable animal model of this disease. Prolonged exposure of rats and dogs to elevated partial pressures of oxygen produced a chronic obstructive disease in the lungs of these animals which anatomically resembles bullous emphysema in man. The disease was characterized by extensive bullae formation, alveolar septal destruction, airway obstruction and pronounced circulatory changes. It is suggested that this condition in laboratory animals may serve as a model for the study of pulmonary obstructive disease.