Bronchial epithelium

Villaschi S, Giovanetti A, Lombardi CC, et al. 1991. Damage and repair of mouse bronchial epithelium following acute inhalation of trichloroethylene. Exp Limg Res 15 601-614. 

It is reasonable to conclude that dose to cells throughout the bronchial tree may contribute to the risk of lung cancer and not just the dose received by certain cells in the large central airways. It is probably also appropriate to evaluate the dose absorbed by cells throughout the depth of bronchial epithelium, i.e. the mean dose,... 

The dose received by cells in the bronchial epithelium from decay of the alpha-emitting radon daughters at the airway surface decreases rapidly with depth in tissue. The data available show that the thickness of bronchial epithelium is highly variable (Gastineau et al., 1972) but the distribution of values can be formalised (Wise,... 

Gastineau, R.M., P.J. Walsh and N. Underwood, Thickness of Bronchial Epithelium with Relation to Exposure to Radon, Health Phys. 23 857-860 (1972). 

It is possible to infer cross population risk if the detailed dose delivered to target cells in bronchial epithelium is calculated for the various population groups since it is the dose which confers the risk. 

Current lung dosimetry models are based on the assumption that basal cells of the bronchial epithelium are the critical target cells for malignant transformation and that the alpha dose to these cells is the relevant radiation dose. 

Radford, E. P., and E. A. Martell, Polonium-210 lead-210 ratios as an index of residence times of insoluble particles from cigarette smoke in bronchial epithelium, in Inhaled Particles IV, Part 2 (W. H. Walton, ed.) pp. 567-580, Pergamon Press, Oxford (1977). 

This paper will present some results of a set of experiments carried out in the hollow airway cast system with ultrafine particles which are or particular interest for the calculation of the dose to the bronchial epithelium from the short lived radon daughters. Detailed deposition efficiencies and intrabronchial distributions are presented elsewhere (Cohen, et al., 1986). 

Herzog and Pletscher (1955) observed squamous metaplasia of the ciliated bronchial epithelium in two patients exposed to undetermined concentrations of phosgene. The metaplasia was observed 3 mo or 3 y postexposure, respectively. 

Lips KS, Volk C, Schmitt BM, Pfeil U, Arndt P, Miska D, Ermert L, Kummer W, Koepsell FI (2005) Polyspecific cation transporters mediate luminal release of acetylcholine from bronchial epithelium. Am J Respir Cell Mol Biol 33 79-88. 

Keywords Bronchial epithelium Pulmonary drug absorption Pulmonary metabolism Drug transport Permeability... 

Chapter 10 In Vitro Models of the Tracheo-Bronchial Epithelium... 

Figure 10.1 Typical tracheo-bronchial and bronchiolar epithelia showing the major cell types. The tracheo-bronchial epithelium showing the pseudostratified nature of the columnar epithelium, principally composed of ciliated cells (C), interspersed with goblet cells (G), brush cells (Br), serous cells (S), Kulchitsky s cells (K) and basal cells (B). The bronchiolar epithelium showing the cuboidal nature of the epithelium, principally composed of ciliated cells (C), Clara cells (Cl) and infrequent basal cells. Muc = mucus Ci = cilia N = nucleus Sec = secretory granules.

The tracheo-bronchial epithelium forms the interface between the conducting airways and inspired air. As described above, the epithelium is layered upon a connective tissue substratum consisting of a basement membrane, lamina propria, and submucosa [6], The submucosa contains elastic fibres, a muscularis mucosa, connective tissues and seromucous glands. Lymphatics are also located in the bronchial walls [2],... 

While all the aforementioned cell types form the epithelial surface of the airways, basal cells reside deep in the tracheo-bronchial epithelium and are not directly in contact with the airway lumen. Basal cells are considered as the stem cell or progenitor cell of the bronchial epithelium and are pyramidal in shape with a low cytoplasmic/nuclear volume ratio [8, 15-17],... 

---