Endocrine cells of bronchial and bronchiolar epithelium.

Among the epithelial elements of the pulmonary airways are cells with features suggestive of endocrine function. Although these cells share a number of properties with the intestinal endocrine (argentaffine) cells, peptide hormones analogous to the multitude of those present in the gastrointestinal tract have yet to be identified in the lung. The oat cell carcinoma, which arises from this cell type, is of importance clinically, yet investigations into the basic properties and functions of this cell have been difficult and sparse, in part due to a lack of appreciation of the problem.