Glycocalyx and glycocalyceal bodies in the respiratory epithelium of nose and bronchi.

The goblet cells of the ciliated respiratory epithelium of the human nose and bronchi and the trachea and bronchi of rabbit, rat, and dog have been investigated with respect to their glycocalyx. The human respiratory epithelium and some of the animal epithelia were found to contain so-called glycocalyceal bodies, i.e., spherical bodies or vesicles with a diameter of about 500 A. These bodies resemble those of the absorptive cells in the human colon and rectum, indicating a close similarity between these two cell types. The presence of such bodies and of prominent microvilli with a core structure has been regarded as diagnostic of primary colorectal carcinoma, but such may also be derived from the respiratory epithelium. The number of glycocalyceal bodies and the prominence of the glycocalyx differ from one goblet cell to the other in the epithelium and are hence properties of the individual cells. There are great species-specific differences with respect to the glycocalyceal bodies; thus, the rat has such bodies in brush cells rather than in goblet cells. Evidence is presented that glycocalyceal bodies are real structures rather than artefacts, but their function(s) remains unknown.