Chang Mun Young, Gwon Tae Mok, Lee Ho Sun, Lee Jun Ho, Oh Seung Ha, Kim Sung June, Park Min-Hyun
Department of Otorhinolaryngology-Head and Neck Surgery, Chung-Ang University College of Medicine, 102 Heukseok-ro, Dongjak-gu, Seoul, 06973, South Korea.
Department of Electrical and Computer Engineering, School of Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
Eur J Pharmacol. 2017 Mar 15;799:67-72. doi: 10.1016/j.ejphar.2017.01.042. Epub 2017 Jan 31.
The present study aimed to evaluate the effects of systemic lipoic acid on hearing preservation after cochlear implantation. Twelve Dunkin-Hartley guinea pigs were randomly divided into two groups: the control group and the lipoic acid group. Animals in the lipoic acid group received lipoic acid intraperitoneally for 4 weeks. A sterilised silicone electrode-dummy was inserted through the round window to a depth of approximately 5 mm. The hearing level was measured using auditory brainstem responses (ABRs) prior to electrode-dummy insertion, and at 4 days and 1, 2, 3 and 4 weeks after electrode-dummy insertion. The threshold shift was defined as the difference between the pre-operative threshold and each of the post-operative thresholds. The cochleae were examined histologically 4 weeks after electrode-dummy insertion. Threshold shifts changed with frequency but not time. At 2kHz, ABR threshold shifts were statistically significantly lower in the lipoic acid group than the control group. At 8, 16 and 32kHz, there was no significant difference in the ABR threshold shift between the two groups. Histologic review revealed less intracochlear fibrosis along the electrode-dummy insertion site in the lipoic acid group than in the control group. The spiral ganglion cell densities of the basal, middle and apical turns were significantly higher in the lipoic acid group compared with the control group. Therefore, systemic lipoic acid administration appears to effectively preserve hearing at low frequencies in patients undergoing cochlear implantation. These effects may be attributed to the protection of spiral ganglion cells and prevention of intracochlear fibrosis.
本研究旨在评估全身应用硫辛酸对人工耳蜗植入后听力保留的影响。将12只Dunkin-Hartley豚鼠随机分为两组：对照组和硫辛酸组。硫辛酸组动物腹腔注射硫辛酸4周。将消毒后的硅胶电极假头经圆窗插入至约5mm深度。在插入电极假头前、插入后4天以及1、2、3和4周时，使用听性脑干反应（ABR）测量听力水平。阈值变化定义为术前阈值与各术后阈值之间的差值。在插入电极假头4周后对耳蜗进行组织学检查。阈值变化随频率而非时间而改变。在2kHz时，硫辛酸组的ABR阈值变化在统计学上显著低于对照组。在8、16和32kHz时，两组之间的ABR阈值变化无显著差异。组织学检查显示，硫辛酸组沿电极假头插入部位的耳蜗内纤维化程度低于对照组。与对照组相比，硫辛酸组基底转、中转和顶转的螺旋神经节细胞密度显著更高。因此，全身应用硫辛酸似乎能有效保留人工耳蜗植入患者的低频听力。这些作用可能归因于对螺旋神经节细胞的保护和对耳蜗内纤维化的预防。
