Rabbit lung after acute smoke inhalation. Cellular responses and scanning electron microscopy
J. Loke, E. Paul, J. A. Virgulto and G. J. Smith
The cellular responses in the lungs of rabbits and the morphologic features
of the tracheobronchial tree by scanning electron microscopy were examined
24 hours following acute inhalation of Douglas fir wood smoke. Thermal
injury to the upper airway was excluded. Injury to proximal tracheal lining
cells was severe and consisted of loss of the epithelium. The changes of
the epithelial barrier in the proximal major bronchi were less severe in
nature. However, the alterations observed by scanning electron microscopy
suggested dysfunction of the mucociliary blanket. Both cell counts of
bronchoalveolar lavage fluid and morphologic findings reflected an increase
in alveolar macrophage response. Smoke-exposed alveolar macrophages showed
significant changes in the surface features. These findings may explain the
tracheobronchitis seen clinically, and the propensity of patients to lung
infection following smoke inhalation.