The Effect of Halothane on Hearing Loss and Apoptosis in Noise Exposing Mouse. |
Seung Woo Ku, Eun Ho Lee, Young Joo Seo, Hyun Jung Lee, Hun Hee Kang, Joung Uk Kim, Seong Sik Kang, Jong Woo Chung |
1Department of Anesthesiology and Pain Medicine, College of Medicine, University of Ulsan, Seoul, Korea. jukim@amc.seoul.kr 2Department of Otolaryngology, College of Medicine, University of Ulsan, Seoul, Korea. 3Asan Institute for Life Sciences, College of Medicine, University of Ulsan, Seoul, Korea. 4Department of Anesthesiology and Pain Medicine, Kangwon National University College of Medicine, Chuncheon, Korea. |
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Abstract |
BACKGROUND In large clinical series, noise induced hearing loss (NIHL) following middle ear surgery has been demonstrated in 1.2% to 4.5% of patients and it is associated with a lower incidence than expected. The aim of the present work was to analyze the effect of halothane anesthesia on NIHL and hair cell morphological change. METHODS We used 40 BALB/c mice with normal Preyer's reflex to investigate the effect of halothane on the NIHL. Control (n = 20) and halothane group (n = 20, respectively) were exposed to 120 dB SPL (sound pressure level), broad band white noise 3 hours daily for 3 consecutive days. The halothane group was anesthetized with halothane while exposed to noise. Hearing thresholds were determined with the auditory brainstem response (ABR). On day 7 post-noise, mice were sacrificed and the cochlea were collected for the histological study. RESULTS ABR thresholds in the halothane group were less elevated after noise exposure than in the control group and then gradually recovered. In control group, the damage to the outer hair cell and supporting cell was noticeable, but not in halothane group. The expression of Bcl-2 protein was detected in halothane group, the expression of Bax protein was seen in control group. As a result in TUNEL stain, the result is positive in the control group but negative in the halothane group. CONCLUSIONS The occurrence of NIHL decreased and the tissue damage was suppressed while anesthetized by halothane. And the noise-induced cell death of hair cell was also suppressed during anesthesia. |
Key Words:
apoptosis; auditory brainstem response (ABR); cochlea; hair cell; halothane; noise induced hearing loss |
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