PULMONARY ENDOCRINE-CELLS IN ANTHRACOSILICOTIC LUNGS

It has been suggested by same studies of human and animal lungs that t he products of pulmonary endocrine cells, particularly gastrin-releasi ng peptide, might play a role in fibrogenesis, but more recent detaile d studies of fibrotic human lungs have failed to confirm this. We have made a detailed quantitative examination of a series of fibrotic huma n lungs to see if we could determine whether there was any relationshi p between endocrine cells and fibrosis. Using immunocytochemistry, we investigated the morphology, content, distribution and number of pulmo nary endocrine cells in 15 pairs of fibrotic lungs from coal miners, a nd compared their features with those of equivalent cells in age-match ed controls. Proliferation of endocrine cells was seen in the lungs of just two miners, in which it was focal and associated with acute bron chitis and bronchopneumonia, There was no difference between the miner s and controls in the appearance (mostly solitary cells), content (pre dominantly gastrin-releasing peptide and calcitonin), distribution (ma inly in small bronchi and bronchioles), or number (4.5 vs 4.1 cells pe r 10,000 epithelial cells, respectively) of endocrine cells. It seems unlikely that the substances secreted by these cells play any role in stimulating fibrosis In human lungs, but rather that they have a funct ion in the inflammatory response to pulmonary injury.