外源性谷氨酸对豚鼠耳蜗内、外毛细胞易损性的比较  

Differential Vulnerability of Inner and Outer Hair Cells of the Guinea Pig Cochlear to the Ectogenesis Glutamate

作　　者：孙勍[1] 李兴启[1] 单希征[2] 孙建和[1] 

机构地区：[1]解放军总医院耳鼻咽喉科研究所,北京100853 [2]武警总医院耳鼻咽喉-头颈外科

出　　处：《听力学及言语疾病杂志》2006年第1期45-47,共3页Journal of Audiology and Speech Pathology

基　　金：国家自然科学基金资助项目(编号39870797)

摘　　要：目的观察外源性谷氨酸对豚鼠耳蜗电位及耳蜗内、外毛细胞的影响。方法将健康豚鼠30只随机分为3组,应用豚鼠全耳蜗灌流技术,分别经耳蜗灌流人工外淋巴液和不同浓度的谷氨酸2小时,记录灌流前和灌流后的耳蜗电位(CM、CAP);同时应用透射电镜技术观察灌流前后耳蜗形态学的变化。结果灌流人工外淋巴液后豚鼠耳蜗电位及形态学无改变;灌流10 mmol/L谷氨酸后CM幅度虽有下降,其非线性特点无改变,CAP阈值平均升高了35 dB;灌流20 mmol/L谷氨酸后CM幅度明显下降但仍保持其非线性特点,CAP阈值平均升高了48 dB,灌流谷氨酸后耳蜗内毛细胞及传入神经纤维出现空化。结论谷氨酸是耳蜗主要的兴奋性传入神经递质,应用外源性谷氨酸可以引起耳蜗内毛细胞及传入神经的损伤,但对耳蜗外毛细胞无影响。Objective To investigate the differential vulnerability of inner and outer hair cells of the guinea pig cochlear to the ectogenesis glutamate. Methods During whole cochlear infusion, the functional properties of the cochlear were measured by CM and CAP. The morphology of the cochlear was monitored by transmission electron microscopy. Results After glutamate perfusion, CM I/O function maintained a nonlinear characteristic, but the amplitude of CM declined. The average CAP threshold was elevated 35 dB after 10mmol/L glutamate perfusion and increased 48 dB after 20 mmol/L glutamate perfusion. The IHCs and afferent dendrites showed cytoplasmic blebs, OHCs appeared normal after glutamate infusion. Conclusion The ectogenesis glutamate can destroy the IHCs and spiral ganglion neurons, but the OHCs remaind normal.

关 键 词：谷氨酸 耳蜗电位 内毛细胞 外毛细胞 

分 类 号：R764.5[医药卫生—耳鼻咽喉科]