[Culture of the epithelium of middle ear in the study of seromucous otitis].

Preliminary results on transport properties of middle ear epithelium in primary culture are reported. Primary cultures of Mongolian gerbil (Meriones unguiculatus) middle ear epithelial cells were undergone. These cells formed polarized monolayers that exhibited domes when grown to confluence on non porous support. Domes are the consequence of active transepithelial transports of solutes and water. On porous support, Na+ and Cl- accumulated in the basal bath and generated a basolateral hyperosmolarity that drove a net water flow. This solutes and water absorption was the consequence of an active Na+ transcellular transport, by means of apical sodium channels, that was responsible for the transepithelial potential difference, lumen negative: -39 +/- 1.2 mV (mean +/- SEM, n = 63). Transport of fluid and ions in the middle ear cavities could play a major role in keeping the cavities fluid-free and air-filled and modulating the mucociliary clearance. Modulation of these transports could be involved at the start of otitis media with effusion, and would contribute to the mucociliary clearance impairment.