普萘洛尔(心得安)对灰鼠噪声性聋的影响

Effect of Propranolol on the Noise-induced Deafness in Chinchilla

目的 研究噪声和 β受体阻滞剂普萘洛尔 (心得安 )对灰鼠耳蜗复合动作电位和耳蜗血流的影响。方法 使用 1/ 2倍频程窄带 ,噪声其中心频率 15 0 0Hz ,强度 115dBSPL ,持续刺激 90分钟。观察不同浓度普萘洛尔对灰鼠耳蜗复合动作电位和耳蜗血流的影响。结果 在噪声刺激期腹膜内注射不同浓度普萘洛尔 ,对耳蜗血流和噪声暂时性阈移无影响。结论 耳蜗微循环中可能无 β受体 。

Objective To investigate the effect of noise and Propranolol on temporary threshold shift(TTS) of the cochlear compound action potential(CAP) and cochlear blood flow(CBF) in chinchilla.Methods After exposure of noise to a non-physiological level (1 500 Hz,1/2 octave narrow band,115 dB SPL,90 min),the temporary threshold shift of the cochlear compound action potential and cochlear blood flow were investigated with different concentration Propranolol(experimental group and saline control group).Results The cochlear blood flow and noise-induced level of temporary threshold shift were not affected by different concentration of Propranolol during noise exposure.Conclusion These results indicate that there be not β receptor present in the cochlear microcirculation of the chinchilla,Propranolol does not protect noise-induced hearing loss.