鼓阶开窗微孔技术注入胰岛素样生长因子-1对庆大霉素致聋豚鼠的治疗作用

Therapeutic effect of insulin-like growth factor-1 injection into the inner ears through scala tympani fenestration on gentamicin-induced hearing loss in guinea pigs

目的探讨通过鼓阶开窗,微孔技术注胰岛素样生长因子-1(IGF-1)入内耳鼓阶,研究IGF-1对感音神经性聋动物模型(庆大霉素致耳聋豚鼠)的治疗作用。方法豚鼠20只,施用庆大霉素致耳聋后均分为IGF-1组和对照组,行鼓阶开窗术,微孔技术注入试剂(IGF-1组注入鼠重组IGF-1,对照组注入人工生理外淋巴液)10μl,分别在术前和术后7、14d行ABR测试;测试完后每组3只断头取听泡,在扫描电镜下观察耳蜗毛细胞改变。结果IGF-1组ABR反应阈(RT)术后7、14d均比术前有显著降低;IGF-1组比对照组RT在术后14d有显著降低。扫描电镜发现对照组较IGF-1组毛细胞受损严重;同时,IGF-1组受损毛细胞表面有指状微绒毛生长。结论微孔技术注入IGF-1可以改善豚鼠受损听力,减轻庆大霉素耳毒性的继续损伤,其机制可能为减轻耳蜗毛细胞的损伤并修复部分毛细胞,同时保护传入神经。

Objective To study the therapeutic effect of insulin-like growth factor-1 （IGF-1） injection into the inner ears through a scala tympani fenestration on sensorineural deafiaess in a guinea pig model of gentamicin-induced heating loss. Methods Twenty guinea pigs with gentamicin-induced heating loss were randomized equally into IGF-1 group and control group. In both groups, scala tympani fenestration was performed for injection of IGF-1 （10μl） or artificial perilymphatic fluid （10 μl）. Auditory brainstem responses （ABR） test was performed before and 7 and 14 days after surgery, respectively, and the cochlea was removed by decollation of 3 guinea pigs from each group after ABR test for observing the changes in the hair cells using scanning electron microscope. Results Significant reduction in the ABR response threshold （RT） occurred in IGF-1 group 7 and 14 days after the surgery, and on day 14, ABR RT showed significant difference between IGF-1 group and the control group. Scanning electron microscopy revealed severer damages of the hair cells in the control group, and in the IGF-1 group, finger-like microvilli was detected on the surface of the damaged hair cells. Conclusion IGF-1 injection in the inner ear through the scala tympani fenestration may ameliorate the damages of the auditory function and relieve sustained toxicity of gentarnicin in guinea pigs possibly by protection and partial repair of the damaged cochlea hair cells as well as protection of the afferent nerves.