BSA sensitized cochleae in secondary immne response (GR-I) and immune complex reaction (GR-2) were studied morphologically. Vacuolar degeneration, swelling of intermediate cells of stria vascularis, protrusion of marginal cells into endolymphatic spase were seen (GR-I). Slight hydrops was present mainly in the basal turn (GR-2). No IgG deposits were found in either group. It appears that the possibility of immune complex deposits in CSS causing direst injury to the vessels of the cochlea is small. These dissimilarities between renal and cochlear tissue is because of differences in regional blood flow, capillary endthelial cells and the existence of the blood-labyrinth barrier.
