小鼠半规管造模的实验技术优势及其应用

Advantages and Application of A Mouse Model of Semicircular Canal Lesioning and Drug Delivery

目的 探讨小鼠半规管阻塞及半规管给药模型建立的可行性及其优势。方法 选取2月龄健康CBA小鼠20只。10只进行外侧半规管和后半规管开窗并阻塞手术,观察术后半规管形态学的变化;另10只进行小鼠经后半规管开窗后注射Texas Red耦合(作为示踪剂)的庆大霉素,后观察荧光在内耳中的分布。结果 建立经小鼠外侧半规管和后半规管开窗并阻塞手术模型后,半规管形态学显示阻塞完全;Texas Red标记的庆大霉素经后半规管注射30分钟后即可成功充满整个内耳,椭圆囊、壶腹以及耳蜗基底膜中也可以清晰观察到荧光。结论 小鼠外侧半规管和/或后半规管阻塞手术的模型建立是确切可行的;通过小鼠半规管开窗注射是一种有效的将药物导入内耳尤其是毛细胞的方法,可为研究药物的耳毒性机制、耳保护性药物的作用机制和基因治疗提供了研究思路和相关技术参考。

Objective To investigate the feasibility of semicircular canal fenestration, lesioning and drug administration in a mouse model for inner ear research. Methods Healthy CBA mice aged 2 months underwent semicircular canal fenestration. Occlusion of the lateral and posterior semicircular canals was established in 10 mice for observation of morphological changes and Texas Red-conjugated gentamicin was injected another 10 mice to trace fluorescence distribution in cochlear, vestibular and crista hair cells. Results Morphology changes consistent to complete semicircular canal occlusion were seen in the mice undergoing lesioning. Texas Red-conjugated gentamicin could filled the entire inner ear 30 minutes after injection into the posterior semicircular canal. Fluorescence was also clearly visible in hair cells in the utricle, crista and cochlea. Conclusion A mouse model of lateral semicircular canal and/or posterior semicircular canal occlusion is feasible. Drug delivery through semicircular canal fenestration may be an effective method to increase drug exposure for inner ear hair cells. Semicircular canal fenestration in mice is a useful model to study mechanisms of ototoxicity, test drugs for inner ear protection and to study gene therapies.