VASCULAR-PERMEABILITY OF THE STRIA-VASCULARIS AND MORPHOLOGY OF THE ENDOLYMPHATIC SAC IN 2 TYPES OF EXPERIMENTAL ENDOLYMPHATIC HYDROPS

We produced two kinds of experimental endolymphatic hydrops. One was i nduced by obliteration of the endolymphatic sac (ES), and the other wa s induced by both systemic keyhole limpet hemocyanin immunization and secondary keyhole limpet hemocyanin challenge into the ES. The vascula r permeability of the stria vascularis in acute and chronic phases was compared between both models by light and electron microscopy using t he tracer method of horseradish peroxidase. Both models showed that th e number of strial capillaries showing horseradish peroxidase leakage was significantly higher in the acute phase than in the chronic phase. In the acute phase, the ES showed acute inflammation in both models. In the chronic phase, extensive fibrosis occurred in the ES obliterati on model, whereas the ES appeared to have a normal shape in the immuno logically induced model. The mechanism of hydrops formation will be co mpared between the two models.