Abstract
The ultrastructure of the tracheal epithelium was studied 5 min and 20 min after i.v. administration of epinephrine (10 mu g/kg b.w.). In the slightly altered pseudostratified columnar ciliated epithelium, goblet cells were mostly overstimulated and damaged.
The degree of their injury was more pronounced 20 min post exposure. An acceleration of the mechanism of their secretion was observed throughout the whole experiment.
Ciliated cells were less impaired in comparison with the goblet ones. Almost no signs of pathological alteration were revealed in their cortical areas.
In the deeper portions of their cytoplasm, the signs of pathological alteration were only slight but were more evident 20 min post exposure. In controls, the average number of cilia/mu m(2) was 9.7+/-0.3.
After the administration of epinephrine, a decrease to 7.4+/-0.4 and 6.9+/-0.1 was recorded, respectively. The alteration of the ciliary border was due not only to the destruction of some cilia but also to the increased incidence of the stimulated goblet cells.
Morphological signs of the impairment of the mucus Row in the airways were noticed as early as 5 min after the administration of epinephrine and were rather prominent 20 min post exposure. Based on our classification of the injury to the airway epithelium, the degree of the damage of the secretory elements was classified as moderate and the impairment of the ciliary border as mild to moderate.