Dexamethasone Effect on Sudden Hearing Loss is Validated in Stress-induced Animal Models: Hypothetical Study

• Published in: Journal of International Advanced Otology Vol. 19; no. 1; pp. 10 - 15
• Main Authors: Hun Jang, Jeong, Cheol Kim, Yeong, Lee, Jin-Sol, Kim, Yeon Ju, Lee, Yun Yeong, Choo, Oak-Sung, Choung, Yun-Hoon
• Format: Journal Article
• Language: English
• Published: Turkey AVES 01.01.2023; Mediterranean Society for Otology and Audiology; European Academy of Otology and Neurotology and the Politzer Society
• Subjects: Analysis; Animals; Central nervous system depressants; Cochlea - pathology; Dexamethasone; Dexamethasone - pharmacology; Electrodes; Enzymes; Glucocorticoids; Hearing; Hearing loss; Hearing Loss, Sensorineural - pathology; Hearing Loss, Sudden - drug therapy; Hearing Loss, Sudden - etiology; Hormones; Hydrocortisone - pharmacology; Laboratory animals; Original; Rats; Steroids; Stress; Treatment Outcome; South Korea; United States > US
• ISSN: 1308-7649; 2148-3817
• DOI: 10.5152/iao.2023.21659

Stress could be a contributing cause of sudden hearing loss. This study intended to develop an animal model of stress-induced sudden hearing loss and to evaluate the effects of dexamethasone. Two stress models (I and II) for rats were designed using various stressors and modified by adjusting the stress protocol to increase the threshold significantly. For the stress model with a significant increase in threshold after stress exposure, changes in cortisol levels according to stress exposure were measured. The threshold shift and the change in the cellular structure associated with stress exposure and dexamethasone administration were analyzed. While hearing thresholds increased only at 16 kHz in rats of stress model I (n=10), the thresholds increased at 16 and 32 kHz in rats of stress model II (n=16). Cortisol level increased after stress exposure (P = .015) in stress model II. Among stress model II rats (stress only and stress+dexamethasone groups), the threshold shift at 16 kHz significantly decreased 1 day after dexamethasone injection in the stress+dexamethasone group (n=8). Histologically, the cochlear cellularity of the stress+dexamethasone group was more compact than that of the stressonly group (n=8). Our preliminary study presented the development of an animal model of stress-induced sudden hearing loss and the positive results of steroids in terms of hearing recovery.