Function of the Stria Vascularis in Endolymphatic Hydrops

Abstract

We examined electronmicroscopically the inner ear of guinea pigs sensitized with the stria vascularis of rabbits. 25, 000 units of HRP were injected through a catheter in the right jugular vein. The tracer was observed in the stria vascularis, around the capillary vessels, in the marginal cells and in the intercellular spaces of these animals. The region of the intermediate cells in the stria vascularis was stained with HRP, and vacuolar degeneration was present in the marginal cells. This implies that the parenchymatous cells of the stria vascularis are damaged. We examined the effect of anaphylatoxins on the stria vascularis.Ten guinea pigs were injected with Zymosan+guinea pig serum+e-aminocaproic acid and 10 guinea pigs with guinea pig serum+e-aminocaproic acid into the carotid artery. Under anesthesia with nembutal, these animals were perfused with 10% neutral formalin and immobilized. Tissues were examined after HE staining. The stria vascularis of various cochlear turns showed marked atrophy except in the basal turn, and also some animals indicated the mild endolymphatic hydrops. These findings suggest that endolymphatic hydrops and other inner ear pathological conditions are related to anaphylotoxins.Furthermore, electronmicroscopic findings included hyperpermeability of the stria vascularis. The increase of permeability may be due to the leakage in intercellular spaces or in the destroyed region of the endothelial cells in addition to the usual vesicular transport.We conclude that the stria vascularis plays an important role in the development of endolymphatic hydrops.