Department of Otorhinolaryngology and Head Neck Surgery, Gulhane Military Medical Academy, Ankara, Turkey.
Otol Neurotol. 2012 Dec;33(9):1672-8. doi: 10.1097/MAO.0b013e31826bf3f6.
To investigate effects of dexamethasone and hyperbaric oxygen therapy (HBOT) on proinflammatory cytokines and hearing levels in the noise-exposed cochlea of rats.
There is an arising concern about negative effects of early initiation of HBOT on hearing in noise-induced hearing loss. Furthermore, effects of HBOT and dexamethasone on cochlear cytokines are not fully elucidated.
Twenty-six rats were divided into 3 groups: control, noise, and treatment groups. Five rats served as control group. White noise at 115 dB sound pressure level was applied to the noise group of 4 rats for 10 days. This group was assigned to a positive control group as it was equivalent to treatment groups. The treatment group of 17 rats underwent the same noise exposure, and then, they were divided into 3 groups based on treatment protocol: 5 and 6 rats received HBOT at the third hour and 24th hour after the noise, respectively, and 6 rats received dexamethasone. Auditory brain stem response threshold was measured in all groups before being assigned to the groups, after the noise exposure and right before being killed. Cytokine levels at the cochlear soft tissues were measured using enzyme-linked immunoassay.
Final thresholds (10 dB and 5 dB nHL-normal hearing level) of HBOT-24th hour and dexamethasone groups were significantly better than that of untreated noise group (22.5 dB nHL) (p < 0.05). There was no significant difference between HBOT-24th hour group (10 dB nHL) and dexamethasone group (5 dB nHL) (p > 0.05). IL-6 and IL-1β of HBOT-third hour group (2.30 ng/mg and 185.43 pg/mg) were significantly higher than those of the noise group (0.91 ng/mg and 131.40 pg/mg), dexamethasone group (1.19 ng/mg and 112.29 pg/mg) and HBOT-24th hour group (1.34 ng/mg and 106.69 pg/mg) (p < 0.05). There was no significant difference in IL-6 and IL-1β of HBOT-24th hour group, dexamethasone group, noise group, and control group (p > 0.05). There was no significant difference in TNF-α of the 3 treatment groups, noise group, and control group (p > 0.05).
The results showed that the most effective method in the treatment of noise-induced hearing loss was early initiation of dexamethasone therapy. There could be negative effects of HBOT on hearing if it is commenced early after the noise (first 3 h). HBOT treatment, which was started at the 24th hour, was found to be an effective method.
研究地塞米松和高压氧治疗（HBOT）对大鼠噪声暴露耳蜗中促炎细胞因子和听力水平的影响。
人们越来越担心早期开始 HBOT 对噪声性听力损失的听力有负面影响。此外，HBOT 和地塞米松对耳蜗细胞因子的影响尚未完全阐明。
将 26 只大鼠分为 3 组：对照组、噪声组和治疗组。5 只大鼠作为对照组。4 只大鼠接受 115dB 声压级的白噪声暴露 10 天。该组被指定为阳性对照组，因为它相当于治疗组。17 只治疗组大鼠接受相同的噪声暴露，然后根据治疗方案分为 3 组：第 3 小时和第 24 小时分别有 5 只和 6 只大鼠接受 HBOT，6 只大鼠接受地塞米松。所有组在被分配到组之前、噪声暴露后和即将处死前测量听性脑干反应阈值。使用酶联免疫吸附试验测量耳蜗软组织中的细胞因子水平。
HBOT-24 小时和地塞米松组的最终阈值（10dB 和 5dB nHL-正常听力水平）明显优于未治疗的噪声组（22.5dB nHL）（p<0.05）。HBOT-24 小时组（10dB nHL）和地塞米松组（5dB nHL）之间无显著差异（p>0.05）。HBOT-3 小时组的 IL-6 和 IL-1β（2.30ng/mg 和 185.43pg/mg）明显高于噪声组（0.91ng/mg 和 131.40pg/mg）、地塞米松组（1.19ng/mg 和 112.29pg/mg）和 HBOT-24 小时组（1.34ng/mg 和 106.69pg/mg）（p<0.05）。HBOT-24 小时组、地塞米松组、噪声组和对照组的 IL-6 和 IL-1β 无显著差异（p>0.05）。3 个治疗组、噪声组和对照组的 TNF-α无显著差异（p>0.05）。
结果表明，治疗噪声性听力损失最有效的方法是早期开始地塞米松治疗。如果 HBOT 在噪声后早期（第 3 小时内）开始，可能会对听力产生负面影响。我们发现，HBOT 治疗在第 24 小时开始是一种有效的方法。
