卡那霉素致聋豚鼠耳蜗电极植入模型的建立及意义

目的:探讨人工耳蜗电极的插入对耳蜗功能的影响,为研究人工耳蜗植入建立相应的动物模型。方法:取听力正常的豚鼠8只,4只注射卡那霉素联合呋塞米致聋,为致聋组;4只仅注射生理盐水,为对照组。对两组动物行听性脑干反应(ABR)及耳声发射(DPOAE)检查后,将耳蜗电极植入左侧耳蜗。结果:致聋组术侧4个频率段ABR阈移随着时间的推移逐渐减小,术后24 h、48 h、72 h时间段比较无显著性差异(P0.05);对照组术侧ABR阈移随着时间的推移逐渐减小,32 kHz频率的三个时间段比较有显著性差异(P0.05),其余3个频率无显著性差异。此外,致聋组与对照组术侧耳ABR阈移比较均无显著性差异(P0.05)。致聋组术前5个频率的DPOAE无法引出,术后DPOAE仍无法引出;对照组术前DPOAE均可引出,术后术侧的DPOAE均无法引出。术后72 h可见电极周围有组织包绕,固定良好,局部未见明显炎症反应。结论:本实验成功建立了卡那霉素致聋的豚鼠耳蜗电极植入模型,可为人工耳蜗植入术后颞骨病理改变的研究提供实验基础。

Establishment of Cochlear Electrode Implantation in a Deaf Guinea Pig Model by Kanamycin

ABSTRACT Objective: To investigate the impacts of cochlear implant (CI) electrode on cochlear function in a guinea pig model, and provide reliable animal model for cochlear implant research. Methods: Eight guinea pigs with normal hearing were selected, four guinea pigs were administered with a single dose of kanamycin followed by furosemide to establish deaf group, while the other four were administered with saline as control group. After ABR and DPOAE tests, the eight animals underwent electrode-insertion surgery on their left ears. Results: In deaf group, ABR threshold shifts in the frequency range 4, 8, 16, and 32 kHz on the operative sides were gradually decreased with time, and the differences among the 24 h, 48 h and 72 h were statistically insignificant (P > 0.05). In control group, ABR threshold shifts in these frequency range on the operative side were gradually decreased with time as well, and the differences among the 24 h, 48 h and 72 h were statistically significant only in 32 kHz (P < 0.05). In deaf group, the DPOAE could not be elicited before and after the surgery; in control group, the DPOAE could be elicited before the surgery, but absent after the surgery. 72 h after the surgery, the electrodes were surrounded with tissue and fixed well, and no inflammatory response was observed. Conclusion: A guinea pig cochlear electrode implantation model with kanamycin-induced deafness was successfully established, which could provide experimental basis for the study of temporal bone pathological changes after cochlear implantation.