Surface topography and distribution of cell types in the rat nasal respiratory epithelium: scanning electron microscopic observations.

Several cell types were identified in the rat nasal respiratory epithelium using scanning electron microscopy. In addition to the previously described ciliated, nonciliated, and goblet cells, the nasal brush cell was identified based on its surface characteristics and its location between nonciliated epithelial cells. Scanning electron microscopy clearly showed the differences in distribution of cell types in the nasal mucosa. The ciliated cells increase in number from the anterior to the posterior areas of the respiratory epithelium with a corresponding decrease in nonciliated cells. However, even at a single cross-sectional area of the nasal cavity, the various surfaces have different proportions of ciliated versus nonciliated cells, e.g., the medial surface of the nasal concha has more ciliated cells than other surfaces. Brush cells are distributed between nonciliated cells of the respiratory epithelium on most surfaces of the nasal cavity including the conchae and the lateral wall. Based on the available information, scanning electron microscopy will be useful in future studies to determine the effects that inhaled toxicants have on cells and on the location of lesions.