Ultrastructural alterations in Clara cells in horses with chronic obstructive lung diseases
Drommer, W.; Kaup, F.J.; Klein, O.; Deegen, E.
Deutsche Tierärztliche Wochenschrift 94(2): 63-67
1987
ISSN/ISBN: 0341-6593 PMID: 3552563 Document Number: 290087
Clara cells in the bronchial epithelium of two healthy horses were compared with those of 5 horses with mild to moderate chronic obstructive pulmonary disease (COPD) and 5 with severe COPD. In early stages of the disease the Clara cells showed loss of granules and an increase of the smooth endoplasmic reticulum and early signs of degeneration. Later there was a great increase of myelin figures and accumulation of granular material in the cytoplasm of the Clara cells. In severe COPD, bronchitis was accompanied by degeneration of Clara cells and transformation into goblet cells and cell types resembling alveolar type II cells. The changes in the Clara cells are regarded as the start of pathological changes in equine COPD; their importance for pulmonary clearance mechanisms are discussed.