Acute changes in cochlear potentials due to cisplatin

• Published in: Hearing research Vol. 149; no. 1; pp. 189 - 198
• Main Authors: Tsukasaki, Naoki, Whitworth, Craig A., Rybak, Leonard P.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2000; Elsevier
• Subjects: Animals; Antineoplastic Agents - pharmacology; Biological and medical sciences; Chinchilla; Cisplatin; Cisplatin - pharmacology; Cochlea - drug effects; Cochlea - physiology; Cochlea - ultrastructure; Cochlear Microphonic Potentials - drug effects; Cochlear microphonics; Drug toxicity and drugs side effects treatment; Electrophysiology; Endocochlear potential; Male; Medical sciences; Microscopy, Electron, Scanning; Ototoxicity; Pharmacology. Drug treatments; Time Factors; Toxicity: respiratory system, ent, stomatology; Endocochlear potential; Cochlear microphonics; Cisplatin; Chinchilla; Ototoxicity; Antineoplastic agent; Toxicity; Internal ear disease; Rodentia; Outer hair cell; Vertebrata; Mammalia; Cell death; Ultrastructure; Animal; Cochlea; ENT disease; Stria vascularis; Degeneration; Microphonic potential
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(00)00182-9

The purpose of this study was to investigate how the hair cells and stria vascularis are affected at the onset of cisplatin ototoxicity. The effects on the endocochlear potential (EP) and the cochlear microphonics (CM) were observed simultaneously in two groups of adult chinchillas receiving as follows: (1) 5 μl of cisplatin (1 mg/ml) in normal saline, and (2) 5 μl of normal saline on the round window. The EP and the CM were recorded for 12–14 h after cisplatin application, and morphological changes were assessed using scanning electron microscopy. Both the EP and the CM amplitude demonstrated a profound reduction, and a very strong correlation was observed between these two values during this time period. Although the reduction of the EP and the CM was observed by 12–14 h, only very slight degeneration of outer hair cells was seen at that time. These data suggested that a reduction of the EP which was caused by the alteration of the stria vascularis might be primarily responsible for very early changes in cochlear function after topical cisplatin application, while later changes were the direct result of hair cell damage.