The protective effect of dopamine on the noiseinduced hearing loss of guinea pigs / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To investigate the protective effect and its frequency selection of dopamine on the inner cell in cochlea when exposed to white-noise;In order to offer an important step on understanding of negative protective modulation of dopamine in the cochlear auditory afferent nerve. METHODS Forty guinea pigs were randomly divided into 4 groups and whole intracochlear perfusions were performed. ① exposed to the 100dB white-noise; ② perfused with artificial perilymph solutions; ③exposed to the white-noise and perfused with artificial perilymph solutions; ④exposed to the white-noise and perfused with Artificial perilymph solutions containing 1mmol/L dopamine. Compound action potential(CAP)evoked by different frequencies tone pip, and cochlear mirophonics(CM)evoked by 4kHz tone burst were recorded from the round window of guinea pigs before and 2h after perfusion. RESULTS In the groups exposed to the white-noise, the CM amplitude and the linearity of input-output function both significantly decreased at 2h(P