Distribution of Mucus-Secreting Cells in Normal Middle Ear Mucosa

Middle ear mucosae of normal guinea pigs and humans were studied with the surface histochemical staining technique. Distribution of the secretory cells closely parallels that of the ciliated cells. Numerous secretory cells were found in the bony portion of the eustachian tube and hypotympanum and small numbers in the antrum (epitympanum) and promontory. Secretory cells stained with both acid-fast Schiff and alcian blue, suggesting the presence of both acidic and neutral mucopolysaccharides. Mucous blanket found in the antrum, hypotympanum, and promontory also stained with PAS-AB alcian blue. It seems reasonable that the mucociliary transportation system participates in the clearance of the hypotympanum, epitympanum, and part of the promontory.