PULMONARY INJURY AND REPAIR - ORGAN-CULTURE STUDIES OF MURINE LUNG AFTER OXYGEN

Abstract

Samples of mouse lung were cultured at various stages of the injury-repair cycle induced by O2. At intervals during and after a 6-day exposure, pulmonary explants were prepared and cultured in media labeled with 3H-thymidine. Lungs cultured during the first 3 days in O2, when only interstitial edema was observed, resembled control explants in morphologic features and labeling. Cultures prepared from animals after 4-6 days of exposure, when necrosis of type 1 epithelial cells and hyaline membranes were observed, showed reduced thymidine uptake and reduced epithelial regeneration. Fibroblastic proliferation and collagen deposition occurred directly beneath areas with hyaline membranes, indicating that, in severely damaged lungs, cellular proliferation is predominantly fibroblastic rather than epithelial. The organ culture system is probably suitable for studying the reparative capacity of injured tissue.