Brog E
Hear Res. 1982 Sep;8(1):93-9. doi: 10.1016/0378-5955(82)90038-7.
Genetically hypertensive rats have been found in previous studies to be more susceptible than normotensive rats to the formation of lesions of the inner ear as a result of excess noise. The present study was designed to investigate whether or not that susceptibility is a direct result of the high blood pressure. Hypertension was induced in 28 Sprague-Dawley rats by placing a 0.25 mm wide silver clip on one renal artery. Systolic blood pressure was measured indirectly by a tail-cuff technique 3 weeks after the operation and again after noise exposure. The animals were kept for one month in noise conditions (100 dB Leq (lin)) simulating those in an industrial milieu. The frequency range was adjusted to correlate to the hearing range of the rat. Auditory sensitivity was assessed electrophysiologically by recording auditory brain stem response to pulses of 1/3-octave filtered full-cycle sine waves. The results showed no correlation between hearing loss and systolic blood pressure. There was no difference between the audiograms obtained from rats with a systolic pressure below 160 mmHg and those obtained from rats with systolic pressures of between 170 and 255 mmHg. These results do not support the hypothesis that high blood pressure is a mechanism underlying noise-induced hearing loss.
在以往的研究中发现，遗传性高血压大鼠比正常血压大鼠更容易因过度噪音而形成内耳损伤。本研究旨在调查这种易感性是否是高血压的直接结果。通过在28只斯普拉格-道利大鼠的一侧肾动脉上放置一个0.25毫米宽的银夹来诱发高血压。术后3周及噪声暴露后，采用尾袖法间接测量收缩压。将动物置于模拟工业环境的噪声条件（等效连续A声级100分贝（线性））下饲养1个月。调整频率范围以与大鼠的听力范围相关。通过记录对1/3倍频程滤波全周期正弦波脉冲的听觉脑干反应，用电生理学方法评估听觉敏感性。结果显示听力损失与收缩压之间无相关性。收缩压低于160毫米汞柱的大鼠与收缩压在170至255毫米汞柱之间的大鼠的听力图无差异。这些结果不支持高血压是噪声性听力损失潜在机制的假说。
