This method is simple to perform with routine histology equipment and is appropriate for the study of acute, cisplatin-induced ototoxicity in rats.

Ci splatin is a chemotherapy agent frequently used to treat different types of neoplasia. Ototoxicity is one of the side-effects which cause significant morbidity and limits its use. This study aimed at assessing the role of apoptosis in cisplatin-induced ototoxicity. Design: experimental study. Materials and Methods: male Wistar rats were treated with intraperitoneal cisplatin, in the doses of 24 and 16 mg/kg. The animals were assessed by means of distortion product evoked otoacoustic emissions (DPEOAE) or brainstem evoked auditory potentials (BEAP) in the third (D3) and fourth (D4) days after drug infusion onset. Following that, their cochleas were removed for immunohistochemical studies of apoptosis -TUNEL method. Results: the group treated with 24 mg/kg showed a significant reduction in DPEOAE amplitude, and such fact was not seen with the 16 mg/kg. Both doses caused an increase in BEAP electrophysiological threshold in D3 and D4. Apoptosis was the injury mechanism responsible for the cisplatin-induced ototoxicity -16 mg/kg dose, when the animals were assessed on D3. Conclusion: apoptosis may be involved in the cisplatin-induced ototoxicity, depending on the dose and time of injury assessment.

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Cisplatin (cis-diamminedicloroplatinum) is an antineoplastic drug used in the treatment of a variety of cancers, especially head-and-neck cancer. Its ototoxicity, however, has been noted as a common side-effect which limits its use and causes significant morbidity. Aim: to assess distortion-product otoacoustic emissions (DPOAE) and brainstem evoked response audiometry (BERA) sensitivity to detect secondary ototoxicity caused by different doses and means of administration of cisplatin in rats. Study Design: Experimental. Material and Methods: Male Wistar rats were intraperitoneally (i.p.) injected with 24 mg/kg cisplatin, divided into three equal doses (8mg/kg) or a single i.p. injection of 16 mg/kg. The animals were evaluated by distortion product otoacoustic emission (DPOAE) or brainstem evoked response audiometry (BERA) on the 3rd and 4th days after the cisplatin injection. Results: Treatment with cisplatin 24 mg/kg resulted in significant DPOAE decrease and it raised the BERA electrophysiological threshold. The 16mg/kg dose could not significantly reduce the DPOAE amplitude, but it raised the animals' hearing thresholds -detected by the BERA. Conclusion:In rats, BERA was more sensitivity than DPOAE at detecting cisplatin-induced ototoxicity in rats considering different doses and means of administration.

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