Electron Mincroscopic Study of Kanendomycin and Vistamycin Ototoxicity

Abstract

The ototoxic effects of kanendomycin and vistamycin on mice were studied by light and electron microscopy.
Toxic reaction were mainly observed in the organ of Corti. Degeneration appeared first in the outer hair cells in the basal turn of the cochlea starting with the increasing of lysosomes, proliferation of smooth endoplasmic reticula and degeneration of mitochondria in the subcuticle area and resulting in the complete loss of hair cells, but the stria vascularis and spiral ligament showed little change. Even after the disappearance of the hair cells, some nerve endings were still present in the organ of Corti but they were also disintegrated in a large dose administration. The degeneration of mitochondria and increasing of lysosomes which were observed one day after the final injection of these dregs were much decreased in long term observation.
Even in case of total loss of the outer hair cells in the basal turn, some of the outer hair cells in the hook region still existed.
Vistamycin was less ototoxic than kanendomycin.