The Feyrter cell in hypoxia.

729-741. It is clear that the bronchial tree has functions beyond the mere conduction of air into the alveolar spaces. In addition to the familiar ciliated respiratory epithelial cells the bronchus is lined by non-ciliated Clara and Feyrter cells. In the present study we investigated the histological and ultrastructural features of the bronchial argyrophilic (Feyrter) cell of the neonatal rat. On electron microscopy this cell has all the features of an APUD cell which is associated with the secretion of polypeptide hormones. It bears a close ultrastructural resemblance to the chief cell of the carotid body and shows the same changes in its membrane-bound bodies on exposure to chronic hypoxia. These are strong grounds for believing that the bronchi and bronchioles have either a chemoreceptor or an endocrine function in the neonatal period.