Ultrastructure of epithelium of terminal bronchioles in rabbits after inhalation of mineral water aerosol
Abstract
Inhalation of mineral water aerosols is a widely used supplementary therapeutic method during the treatment of chronic respiratory diseases. We decided to proceed our previous experiments dealing with the effect of a short-time inhalation of this aerosol on the tracheal epithelium by the evaluation of reaction of the epithelium in distal airways-terminal bronchioles.
Laboratory rabbits inhaled an aerosol of special mineral water for 10 min and material for the electron microscopic examination was collected immediately after inhalation. The ultrastructure of the epithelium of terminal bronchioles was evaluated quantitatively.
Computer image analysis was used in the evaluation of cytoplasm of Clara cells. As in control animals, terminal bronchioles of rabbits exposed to 10-min inhalation of the mineral water aerosol were lined with simple columnar epithelium composed of ciliated and Clara cells.
On the apical surfaces of ciliated cells, formation of cytoplasmic protrusions leading sometimes to a degeneration of free cilia was recorded. In deeper layers of their cytoplasm, mild marks of the pathological alteration were observed.
In secretory Clara cells, tendency to increased proliferation was recorded. This proliferation was not accompanied by elevated liberation of the secretion stored in secretory granules.
Only few Clara cells revealed signs of the pathological alteration, their degeneration was not recorded. The findings of the pathological alteration of the epithelial cell cytoplasm and their increased proliferation testify that the homeostasis of the epithelium was damaged and admonish to the heedfulness in the indication even of such seemingly harmless therapeutic procedures.