[Ultracytochemical observation of secretory cells and surfactant-like lamellar bodies in mucosa of eustachian tube].

The distribution of secretory cells and surfactant-like lamellar bodies in mucosa of the guinea pig eustachian tube were studied ultracytochemically. Classified by means of their morphologic characteristics, three types of secretory cells were identified. The dark granulated cells were predominant in the tympanic orifice, the mixed cells were predominant in the isthmus portion, while the light cells were predominant in the pharyngeal orifice. The distribution of the secretory cells in different part of the eustachian tube might play a role in the pathogenesis of middle ear effusions. Surfactant-like lamellar bodies were found in ciliated cells, nonciliated cells and secretory cells of the eustachian tube mucosa. Surfactant-like lamellar bodies (surfactant-like substance) are important in maintaining the physiological function of the eustachian tube, their behavior in normal and pathological states should be further studied.