Adelman Cahtia, Freeman Sharon, Paz Ziv, Sohmer Haim
Speech and Hearing Center, Hadassah University Hospital, Hebrew University Hadassah Medical School, Jerusalem, Israel.
Audiol Neurootol. 2008;13(4):266-72. doi: 10.1159/000115436. Epub 2008 Feb 7.
The permanent threshold shift (PTS) following exposure to intense noise may be due to the noise-induced excessive vibrations in the cochlea or to the generation of elevated levels of reactive oxygen species. Thus, it is possible that the resulting PTS may be reduced if the cochlear amplifier could be temporarily depressed beginningjust before the onset of the noise and continuing during the noise exposure or if antioxidant drugs were administered. These possibilities were assessed in mice by administering a single injection of salicylic acid (an antioxidant drug which also reversibly depresses the motor protein prestin of the cochlear amplifier) just before, and in other mice, just after, 3.5 h of 113-dB SPL broadband noise exposure. The PTS in the mice injected with salicylic acid just before the noise exposure was significantly smaller than that in mice exposed to the same noise without salicylic acid. The PTS in the latter was not significantly different from that in mice who received the drug just after the noise. Thus a single injection of salicylic acid, just before a noise exposure, can protect the ear from a noise-induced hearing loss.
暴露于高强度噪声后出现的永久性阈移（PTS），可能是由于噪声引起的耳蜗过度振动，或是由于活性氧水平升高所致。因此，如果能在噪声开始前就暂时抑制耳蜗放大器，并在噪声暴露期间持续抑制，或者给予抗氧化药物，那么由此产生的PTS可能会降低。通过在113分贝声压级宽带噪声暴露3.5小时之前给小鼠单次注射水杨酸（一种抗氧化药物，也能可逆地抑制耳蜗放大器的马达蛋白prestin），以及在其他小鼠噪声暴露3.5小时之后给药，来评估这些可能性。在噪声暴露前注射水杨酸的小鼠的PTS，显著小于暴露于相同噪声但未注射水杨酸的小鼠。后者的PTS与在噪声暴露后才接受药物治疗的小鼠的PTS没有显著差异。因此，在噪声暴露前单次注射水杨酸，可以保护耳朵免受噪声引起的听力损失。
