Giant to small emphysematous bullae induced by Sephadex beads and carrageenan

The effects of disturbances of the pulmonary circulation on the formation of pulmonary emphysematous bullae in rabbits were studied with the use of changes in the parenchyma of lungs insulted by both pulmonary embolization with Sephadex beads and carrageenan-induced pneumonia. Rabbits given one of the larger doses of Sephadex and then carrageenan in solution had giant bullous lesions in the lobe treated with those agents 2 months later. More animals had bullous lesions in the groups given the larger doses of Sephadex than in groups given the smallest dose or none. In animals killed after 2 weeks, bullous lesions were found, whereas there were none in those killed after 1 week. These results suggest that the size and number of bullous lesions forming in the treated lobes are associated with the dose of Sephadex. Giant and small bullous lesions are varieties of the same disorder, and there seems to be a latent period for development.