Endocrine-like cells of the pulmonary epithelium of the human adult lung

Abstract

The morphological and histochemical characteristics of endocrine-like cells of the pulmonary epithelium of the right lower lobe of 12 human adult lungs were studied. Few cells were reactive to the argyrophil silver method of Grimelius and of Sevier and Munger and cells with a similar morphology and distribution emitted a green or yellow fluorescence after treatment of the lung epithelium with the amine presursors L-DOPA or L-HTP, respectively. A greater number of cells seems to be demonstrated by electron microscopy. The cells were characterized by small, round secretory granules showing a central dense core and a very thin clear halo between the core and the surrounding membrane. The cells are thought to be related to the endocrine-like cells of the pulmonary epithelium of the human foetal lung and to cells of carcinoids of larger bronchi.

The effect of dopamine on lung liquid production by in vitro lungs from fetal guinea‐pigs

“…Histochemical studies suggest that dopamine is produced by decarboxylation of ¬_DOPA (l-3,4-dihydroxyphenylalanine) by the cells of the internal neuroendocrine system of the lungs (Cutz et al 1974;Hage, 1976;Scheuermann, 1991). This system, which has many similarities to the adrenal medulla, is both activated and at its maximal development at birth (Scheuermann, 1991).…”

“…This system, which has many similarities to the adrenal medulla, is both activated and at its maximal development at birth (Scheuermann, 1991). In the human, these neuroendocrine cells can be seen throughout the second half of gestation; they appear to reach their greatest development at or near delivery, and then decline in the months after birth (Hage, 1976;Johnson et al 1982). The same system is seen in guinea-pigs, mice and rabbits, but in the rabbit a number of independent studies have shown a dramatic but temporary loss of amine fluorescence just prior to birth (Hage, 1976;Sorokin et al 1982;Redick & Hung, 1984).…”

“…Like the adrenal medulla, the neuroepithelial bodies receive cholinergic innervation. Significantly, this system is maximally developed around birth, and contains more cell types than in the adult; it appears to be activated at birth, although the function is unknown (Cutz et al 1974;Hage, 1976;Sorokin et al 1982;Redick & Hung, 1984;Cutz et al 1984;Scheuermann, 1991). The cells show immunoreactivity typical of many agents, notably somatostatin, a peptide which appears to be generated after the first breath and which is known to halt lung liquid production in in vitro lungs ).…”

Effects of serotonin on airways: recent developments

“…Studies on normal adult human lung have noted a few immunoreactive neuroendocrine cells (55,56,115,116), which are located mainly in the terminal airways (115, 116). However, specimens from segmental resections for bronchiectasis with and without associated emphysematous changes (54) have shown an increase in solitary bronchial neuroendocrine cells and, along with specimens from patients with pulmonary fibrosis (115,116), have shown areas of focal and linear neuroendocrine hyperplasia.…”

Neuroendocrinelike (small granule) epithelial cells of the lung.

“…Both light and electron microscopic studies have shown that K cells are usually flask-, oval-or pyramidalshaped with most of the cytoplasm concentrated at the base of the cells next to the basal lamina (10,15,22,25,48,58,93,94). Occasionally, lateral dendritelike cytoplasmic processes extend between nearby epithelial cells (10,13,15,94).…”