Abstract
Potassium pyroantimonate added to fixative solutions has been used to study tissue localization of sodium ions. The resulting precipitate in the guinea pig stria vascularis and spiral ligament is distributed throughout the tissue. The greatest concentration of the deposits is localized along the cellular side of the infolding plasma membranes of stria epithelium. In the spiral ligament, the dense concentration of the precipitate is found along the cellular side of spiral ligament connective tissue cells. These findings suggest that sodium ions might be transported through the stria vascularis under the influence of ATP-ase localized on the infolding plasma membrane of the stria epithelium, but the role of the spiral ligament in the ion transport is not certain.