Potentiation of octave-band noise induced auditory impairment by carbon monoxide
Potentiation of octave-band noise induced auditory impairment by carbon monoxide
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DOI：
10.1016/s0378-5955(99)00044-1
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发表时间：
1999-06-01
期刊：
影响因子：
2.8
通讯作者：
Fechter, LD
中科院分区：
文献类型：
--
作者：
Chen, GD;Fechter, LD
在我们实验室以前的研究中，已经发现宽带噪声引起的听力损失通过同时暴露于一氧化碳（CO）而增强。在本研究中，倍频程噪声引起的听觉障碍进行了研究，与CO的存在下，在1500，1200，700，500和300 ppm的水平和零（噪声单独）。使用了四个倍频程噪声（1.2-2.4、2.4-4.8、4.8-9.6和9.6-19.2 kHz）。实验对象（大鼠）分组暴露（8小时），以每一个噪音，CO和它们的组合。4周后记录复合动作电位（CAP）和耳蜗微音电位（CM）。当CO水平达到500 ppm或更高时，噪声引起的CAP阈值和CM等幅曲线的升高被同时CO暴露增强。单独CO暴露对CAP或CM没有影响。CO增强可以发生在任何频率区域，这取决于噪声带。在噪声和CO单独不引起阈值偏移的某些情况下，组合暴露也可引起阈值偏移。CAP和CM显示的增强的大小是相似的，表明CO增强的可能来源于对外毛细胞的损伤。有趣的是，单独由噪声引起的听力损失逐渐恢复（部分），但由组合暴露引起的听力损失没有恢复。这种增强作用可能是由于细胞修复CO引起的噪声损伤的能力降低。（C）1999 Elsevier Science B. V.保留所有权利。
In previous studies from our lab, broadband noise induced hearing loss has been found to be potentiated by simultaneous carbon monoxide (CO) exposure. In the present study, octave-band noise induced auditory impairment was studied with the presence of CO at levels of 1500, 1200, 700, 500 and 300 ppm and zero (noise alone). Four octave-band noises (1.2-2.4, 2.4-4.8, 4.8-9.6 and 9.6-19.2 kHz) were used. Experimental subjects (rats) were grouped for the exposure (8 h) to each noise, CO and their combinations. The compound action potential (CAP) and cochlear microphonics (CM) were recorded 4 weeks after the exposure. The noise induced elevation of the CAP threshold and the CM iso-amplitude curve were potentiated by the simultaneous CO exposure when the CO level reached 500 ppm or higher. CO exposure alone had no effect on CAP or CM. The CO potentiation can occur in any frequency region depending on the noise band. The combined exposure can also induce threshold shifts in some cases in which both the noise and the CO alone did not cause threshold shifts. The size of the potentiation shown by CAP and CM was similar, indicating a possible origin of the CO potentiation from the damage to the outer hair cells. Interestingly, the hearing loss induced by noise alone gradually recovered (partially), but the hearing loss caused by the combined exposure did not. The potentiation may be due to the reduction of the cell's ability to repair noise induced damage by CO. (C) 1999 Elsevier Science B.V. All rights reserved.