Effects of Cigarette Smoking on Hearing Recovery From Noise-Induced Temporary Hearing Threshold Shifts in Mice
Effects of Cigarette Smoking on Hearing Recovery From Noise-Induced Temporary Hearing Threshold Shifts in Mice
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DOI：
10.1097/mao.0b013e318225575a
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发表时间：
2011-08-01
影响因子：
2.1
通讯作者：
Chung, Jong Woo
中科院分区：
文献类型：
--
作者：
Ahn, Joong Ho;Joo, Hyun Seok;Chung, Jong Woo
假设：吸烟可能加剧噪音引起的听力损失。背景：许多流行病学研究表明，吸烟是噪声性听力损失的主要危险因素。方法：BALB/c小鼠被动吸烟2 h/d，连续2周，然后对110 db声压级白噪声1次暴露3 h。在噪声暴露前和暴露后1、3、5、7、14、21和28天，通过音爆刺激和畸变产物耳声发射的听觉脑干反应来评估听力。氧化应激和缺氧分别用8-oxoG和缺氧诱导因子1 α免疫染色评估。结果：吸烟和噪声同时暴露的对照组小鼠和只暴露于吸烟的小鼠的听力阈值没有变化。相比之下，只暴露于噪音或吸烟加噪音的小鼠的听力阈值突然增加。在只暴露于噪音的小鼠中，听力阈值在2周后恢复到噪音前的水平。然而，在暴露于吸烟和噪音的小鼠中，听力损失明显更高，听力阈值直到4周后才恢复到暴露前的水平。纯吸烟组和吸烟加噪声组小鼠内耳8-oxoG和缺氧诱导因子1 α呈阳性染色，与纯噪声组小鼠相似，对照组小鼠内耳未见阳性染色。结论：吸烟可增强噪声对听力的危害，干扰耳蜗的恢复机制。
Hypothesis: Cigarette smoking may potentiate noise-induced hearing loss.Background: Many epidemiological studies have shown that cigarette smoking is a major risk factor for noise-induced hearing loss.Methods: BALB/c mice were exposed to passive smoking for 2 h/d for 2 weeks before exposure to 110-dB sound pressure level white noise for 3 hours once. Hearing was assessed via the auditory brainstem response with tone-burst stimulation and distortion product otoacoustic emissions before and at 1, 3, 5, 7, 14, 21, and 28 days after noise exposure. Oxidative stress and hypoxia were assessed by immunostaining with 8-oxoG and hypoxia-inducible factor 1 alpha, respectively.Results: Control mice unexposed to both smoking and noise and mice exposed to smoking only showed no shift in hearing threshold. In contrast, mice exposed to noise only or smoking plus noise showed abrupt increases in hearing threshold. In mice exposed to noise only, hearing threshold returned to prenoise levels after 2 weeks. However, in mice exposed to smoking plus noise, the loss of hearing was significantly higher, and hearing threshold did not return to the pre-exposure levels until 4 weeks later. Positive staining with 8-oxoG and hypoxia-inducible factor 1 alpha were observed in the inner ear of the smoking-only and smoking-plus-noise group similar to noise-only mice, whereas no positive staining was observed in control group.Conclusion: These results indicate that cigarette smoking may potentiate the harmful effects of noise on hearing and disturb the recovery mechanism in the cochlea.