MORPHOLOGICAL AND FUNCTIONAL-CHARACTERISTICS OF THE DIFFERENT CELL-TYPES IN THE STRIA VASCULARIS - A COMPARISON BETWEEN CELLS OBTAINED FROMFRESH TISSUE PREPARATIONS AND CELLS CULTURED IN-VITRO

Endolymph is the only extracellular fluid in the body which is charact erized by an intracellular-like ion composition. The molecular mechani sms responsible for the production of endolymph and the regulation of endolymph composition are still unknown to a large extent, although th e stria vascularis (SV) is believed to play an important role for thes e functions. A basic requirement for investigating the function of dif ferent cell types in the SV is the establishment of a method, which in creases the accessibility of the tissue with maintained cell viability and function. In this study, fresh tissue preparations and cultured c ells from SV, harvested from pigmented guinea pigs, were established. Marginal cells, intermediate/melanocyte-like cells and fibroblasts cou ld be discerned in the cell cultures with bright-field microscopy, tra nsmission and scanning electron microscopy as well as immunohistochemi stry, using polyclonal antibodies against cytokeratin and vimentin. In order to study functional characteristics of the fresh tissue prepara tions and the cell cultures, changes in the cytoplasmic free Ca2+ conc entration were determined with the fura-2 method. The cultured cells, of different types in the SV, are a suitable model for future studies of the molecular mechanisms behind the production of endolymph and the regulation of endolymph composition.