THE CELLS OF THE TRACHEO-BRONCHIAL EPITHELIUM OF THE MOUSE - A QUANTITATIVE LIGHT AND ELECTRON-MICROSCOPE STUDY

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  • 1 January 1981
    • journal article
    • research article
    • Vol. 132  (JAN) , 71-84
Abstract
Relative numbers of different cell types were assessed in the conducting airways of the specific pathogen free (S.P.F.) mouse. Particular attention was paid to the non-ciliated secretory cells. The number, type and form of these cells were investigated at 5 airway levels from the trachea to the distal conducting bronchi with light microscopy and EM. The majority (50-60%) of non-ciliated cells in the S.P.F. mouse were Clara cells; 3 forms were recognized. These may represent different stages in the epithelial cell turnover. Profiles indicating apocrine and merocrine secretion were observed. Clara cells containing scattered mucous granules or ciliary bases were noted. Mucous and ciliated cells may arise from Clara cells in the mouse. Mucus-producing tissue was rare in the airway of the S.P.F. mouse, sub-mucosal glands being confined to the larynx and the most rostral portions of the trachea. Epithelial mucous and serous cells were also infrequent in the clean animal and none was seen in the intrapulmonary airways. In non-barrier maintained animals mucous cells were observed at every airway level. Free nerve endings were not seen in the epithelium. This may be related to the restricted ability of mice to cough. The limited mucus and lack of cough may be related to the small diameter of the mouse airways.