Cisplatin ototoxicity in the Sprague Dawley rat evaluated by distortion product otoacoustic emissions

The present study has evaluated the use of distortion product otoacoustic e mission (DPOAE) responses in the detection of cisplatin-induced ototoxicity in a Sprague Dawley rat animal model, The cisplatin was administered as a 16 mg/kg, dose introduced by a slow 50-min intraperitoneal infusion. Data f rom three DP-gram protocols, DPOAE input-output responses at 8 kHz, and aud itory brainstem responses (ABRs) at 8, 12 and 16 kHz were collected before and 72 h after treatment. The post-treatment ABRs at 16 kHz showed the grea test mean threshold shift of 33.6 dB. The post-treatment DP-gram data showe d significant reduction of the signal to noise ratios in the majority of th e frequencies tested, across aft tested protocols. The data suggest that th e most sensitive DPOAE procedure for the early detection of the cisplatin-i nduced ototoxic damage is the DPOAE I/O protocol. Morphological analyses in dicated that the inner hair cells remained intact, while several types of a lterations were observed in the arrangement of the stereocilia in the outer hair cells.