[Cisplatin induced vestibular damage]

Cisplatin (CDDP) is known to have toxic effects on the inner ear. There has been numerous reports of hearing disturbances and cochlear damage following CDDP treatment, but very few concerning vestibular disturbances. In this study, guinea pigs were injected peritoneally with either 5 mg/Kg or 10 mg/Kg CDDP. Pathological changes were observed immediately after CDDP administration. SEM investigation showed that exfoliation of supporting cells and destruction of cilia were extensive in the central part of the ampullae, while cells at both ends of the ampullae were rather well preserved. Cilia in the utricles were deformed but not exfoliated, and saccules were almost normal. TEM investigation showed that type I cells were more heavily damaged than type II cells in the ampullae and utricles, as revealed by bulging of the cuticular free area and accumulation of cytoplasma in cavities. Deeper layers of cells and nerve fibers were not damaged, however. The destruction proceeds with cavities developing in mitochondria, then in the rough endoplasmic reticula and nuclear membrane. In type I cells, smaller cavities combine to form larger ones under the cuticular plate. The findings of this study suggest that CDDP destroys enzymes, nuclear acids and protein metabolizing organelles in the cell.