Bronchiolar epithelial lesions in spontaneously breathing premature newborn rabbits

Premature rabbit neonates were stimulated to breathe for time periods varying between 5 and 150 min. The distribution of bronchiolar epithelial lesions was determined morphometrically. Animals breathing for 5-10 min had no lesions. Focal necrosis and desquamation of bronchiolar epithelium were found in 36 of 46 animals breathing for 15-150 min. These lesions were similar to those previously observed in premature rabbit neonates after a few minutes of artificial ventilation.