R-phenylisopropyladenosine attenuates noise-induced hearing loss in the chinchilla
R-phenylisopropyladenosine attenuates noise-induced hearing loss in the chinchilla
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DOI：
10.1016/s0378-5955(97)00143-3
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发表时间：
1997-11-01
期刊：
影响因子：
2.8
通讯作者：
Henderson, D
中科院分区：
文献类型：
--
作者：
Hu, BH;Zheng, XY;Henderson, D
活性氧对活组织具有细胞毒性，被认为是噪声引起的听力损失的部分原因。本研究将一种稳定的非水解腺苷类似物R-苯基异丙基腺苷（R-PIA）拓扑地应用于龙猫右耳圆窗，左耳圆窗应用生理盐水（对照）。然后将动物暴露于105 dBSPL的4kHz倍频程噪声中4 h，测量下丘诱发电位阈值和畸变产物耳声发射（DPOAE），并记录毛细胞损伤。在这一点上，R-PIA治疗耳和对照耳之间的阈值偏移没有显著差异。然而，在噪声暴露后4天，在4和16 kHz之间的频率下，R-PIA处理的耳朵比盐水处理的耳朵显示出20-30 dB的恢复。更重要的是，噪音暴露20天后进行的阈值测量显示，R-PIA治疗耳朵的永久阈值变化减少了10-15 dB。R-PIA处理耳DPOAE振幅恢复较好，外毛细胞损失较轻。结果提示，R-PIA处理耳可促进噪声暴露后外毛细胞的恢复过程。
Reactive oxygen species, which are cytotoxic to living tissues, are thought to be partly responsible for noise-induced hearing loss. In this study R-phenylisopropyladenosine (R-PIA), a stable non-hydrolyzable adenosine analogue which has been found effective in upregulating antioxidant enzyme activity levels, was topologically applied to the round window of the right ears of chinchillas, Physiological saline was applied to the round window of the left ears (control). The animals were then exposed to a 4 kHz octave band noise at 105 dB SPL for 4 h, Inferior colliculus evoked potential thresholds and distortion product otoacoustic emissions (DPOAE) were measured and hair cell damage was documented, The mean threshold shifts immediately after the noise exposure were 70-90 dB at frequencies between 2 and 16 kHz. There were no significant differences in threshold shifts at this point between the R-PIA-treated and control ears. By 4 days after noise exposure, however, the R-PIA-treated ears showed 20-30 dB more recovery than saline-treated ears at frequencies between 4 and 16 kHz. More importantly, threshold measurements made 20 days after noise exposure showed 10-15 dB less permanent threshold shifts in R-PIA-treated ears. The amplitudes of DPOAE also recovered to a greater extent and outer hair cell losses were less severe in the R-PIA-treated ears, The results suggest that administration of R-PIA facilitates the recovery process of the outer hair cell after noise exposure.