title: A new type of cell in the pulmonary epithelium of the newt Triturus alpestris Laur. A scanning and transmission electron microscopic study.
abstract: Single cells of a new type appear scattered among pneumocytes in the pulmonary epithelium. The surfaces of these cells communicate with the air space and display numerous finger-like microvilli. In comparison to pneumocytes, these cells have a more lucid cytoplasm and their apical parts contain large amounts of electron-lucent vesicles and electron-dense granules, which are probably released into the lumen of the lung. These secretory cells exhibit a yellow formaldehyde-induced fluorescence, which suggests that they belong to the class of APUD cells.
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004847:Epithelial Cells; D005260:Female; D008168:Lung / Q000166:cytology*; D008297:Male; D008854:Microscopy, Electron; D009940:Organoids / Q000648:ultrastructure; D014319:Triturus / Q000033:anatomy & histology*