Sheppard Adam M, Zhao Deng-Ling, Salvi Richard
Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY 14214, USA.
Department of Radiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu Providence, China.
J Otol. 2018 Jun;13(2):59-64. doi: 10.1016/j.joto.2018.03.002. Epub 2018 Apr 7.
A commonly used anesthetic, isoflurane, can impair auditory function in a dose-dependent manner. However, in rats, isoflurane-induced auditory impairments have only been assessed with auditory brainstem responses; a measure which is unable to distinguish if changes originate from the central or peripheral auditory system. Studies performed in other species, such as mice and guinea-pigs, suggests auditory impairment stems from disrupted OHC amplification. Despite the wide use of the rat in auditory research, these observations have yet to be replicated in the rat animal model. This study used distortion product otoacoustic emissions to assess outer hair cell function in rats that were anesthetized with either isoflurane or a ketamine/xylazine cocktail for approximately 45 min. Results indicate that isoflurane can significantly reduce DPOAE amplitudes compared to ketamine/xylazine, and that responses were more variable with isoflurane than ketamine/xylazine over the 45-min test period. Based on these observations, isoflurane should be used with caution when assessing peripheral auditory function to avoid potentially confounding effects.
一种常用的麻醉剂异氟烷能够以剂量依赖的方式损害听觉功能。然而，在大鼠中，异氟烷引起的听觉损伤仅通过听觉脑干反应进行评估；这种测量方法无法区分变化是源于中枢听觉系统还是外周听觉系统。在其他物种（如小鼠和豚鼠）中进行的研究表明，听觉损伤源于外毛细胞放大功能的破坏。尽管大鼠在听觉研究中被广泛使用，但这些观察结果尚未在大鼠动物模型中得到重复验证。本研究使用畸变产物耳声发射来评估用异氟烷或氯胺酮/赛拉嗪混合剂麻醉约45分钟的大鼠的外毛细胞功能。结果表明，与氯胺酮/赛拉嗪相比，异氟烷可显著降低畸变产物耳声发射的幅值，并且在45分钟的测试期内，异氟烷引起的反应比氯胺酮/赛拉嗪引起的反应更具变异性。基于这些观察结果，在评估外周听觉功能时应谨慎使用异氟烷，以避免潜在的混淆效应。
