Abstract: | This study was performed to determine whether the lung histological changes which occur in rabbits following intravenous injection of killed Bacilli Calmette-Guérin (BCG) are accompanied by measurable changes in pulmonary function. We measured pulmonary function in New Zealand white rabbits 3 weeks after intravenous injection of BCG and in normal rabbits. After a tracheostomy and carotid artery catheterization was performed, each anesthetized rabbit was placed in a body plethysmograph for pulmonary function testing. Following the measurements, the lungs were removed for weighing and histological evaluation. In the BCG-treated rabbits, the lung weight/body weight ratios were 152% greater, the pulmonary resistance was 104% higher, dynamic compliance was 45% lower, minute ventilation was 28% greater, and the delta AaPO2 gradient was 13 torr higher than in the normal control rabbits. Histological evaluation of the BCG-treated animals revealed diffuse pulmonary involvement with non-caseating granulomas. |