Primary culture of strial marginal cells of guinea pig cochlea: growth, morphologic features, and characterization.

To further investigate the cellular mechanisms involved in the formation of endolymph, primary cultures of marginal cells of guinea pig were established. Minute explants obtained by mechanical dissociation of stria vascularis were plated on collagen type I precoated impermeable substrate in serum-free, hormone-supplemented medium. A confluent layer of epithelial-like cells was obtained within 2 weeks. The cultured cells formed domes, demonstrating that they retain some of their transepithelial properties. Polarization was also suggested by electron microscopic observation of apical microvilli and tight junctions. Immunohistochemical methods revealed that the cultured cells coexpressed cytokeratin and vimentin, demonstrating their epithelial origin, although some degree of dedifferentiation occurred. Thus, a primary culture of marginal cells can be established that may be a suitable model for an in-depth investigation of the function of the marginal cells.