Ultrastructural investigation of changes of pulmonary surfactant system in experimental emphysema produced by intratracheal elastase instillation.

In this study the dynamic changes of the pulmonary surfactant system in guinea pigs were observed by scanning electron microscopy, transmission electron microscopy and special electron stain for surfactant. The results showed that in the early stage of instillation of elastase, the pulmonary surfactant decreased. After one week, it increased gradually. Type II epithelial cells proliferated and their secretion increased. By the 25th day, the pulmonary surfactant system tended to return to normal, indicating that the changes of the pulmonary surfactant system may have some effect during the developing process of emphysema.