Cytotoxic effects of 3-methylindole on alveolar epithelial cells and macrophages: with special reference to
microtubular and filamentous assemblies in alveolar
type I cells of bovine lung
The alveolar type I cell is a major
permeability barrier between the pulmonary interstitium
and alveolar spaces and its thin cytoplasmic processes are
greatly susceptible to injury. These cells are often
observed to undergo progressive vesiculation,
vacuolization and desquamation during 3-methylindole
(3MI)-induced acute pulmonary edema after oral
administration in goats and cattle. The present study
describes proliferation of SER and the presence of
polymerized tubulin in the form of microtubules
arranged in large bundles shown at ultrastructural level
as well as with immunofluorescence staining for tubulin
in alveolar type I cells 72 hours after 3MI treatment. Such
changes were not seen in pulmonary endothelial cells,
alveolar type I1 cells, alveolar macrophages and
neutrophils. The possible role of microtubules in
alveolar type I cell as a mechanistic support to resist
disruption against the forces of interstitial and alveolar
edema is compared with alveolar type I1 cells, alveolar
macrophages and neutrophils. The latter cells undergo
dynamic movements in response to inflammatory stimuli
and therefore did not show microtubules in their cytoplas