庆大霉素损害鸡耳蜗后毛细胞再生的超微结构及其与听功能恢复的关系

ULTRASTRUCTURAL OBSERVATIONS ON REGENERATING HAIR CELLS AND FUNCTIONAL RECOVERY IN THE AVIAN COCHLEA FOLLOWING GENTAMYCIN OTOTOXICITY

给实验组鸡按50mg／（kg·d）剂量肌注庆大霉素共10d后，间隔1、3、6、9和12d对实验组和对照组鸡耳蜗电位（Ap）及听觉脑干诱发电位（ABR）进行测定，随后处死动物，用透射电镜（TEM）和扫描电镜观察鸡基底乳头（BP）毛细胞再生的超微结构和过程，结果可见毛细胞再生来源于Bp表层扁平状或立方形上皮细胞，在早期再生毛细胞胞质密度高，含有大量的线粒体，随后静纤毛长出，细胞核出现，表皮极发育成熟时静纤毛束形成，其毛细胞底部的神经末梢已长出，此时伴有Ap和ABR阈值的恢复。说明再生毛细胞形态成熟时已具有听觉功能的恢复，再生毛细胞在受损耳蜗听功能的恢复过程中起主要作用。

Experimental fowls were injected with 50mg/(kg d ) of gentamycin sulfate for lodays. After the last injection, the experimental fowl groups were allowed to survive 1, 3, 6, 9 and 12 days before they were killed. Auditory-evoked po-tential was measured and examination of the cochlea was performed by trasmission electron microscope (TEM) and scanning electron microscope(SEM) af-ter Ap and ABR measurements. The experimental results found that regenerating hair cells were the cuboid epithelial cells on the surface of Bp. The cy- toplasm of these hair cells were high density and heavy staining.The cells contained nurnerous mito-chondria which were large and had obvious crests on the early time. After several days, stereocilia oc-curred and nucleus appeared. When stereocilia bun-dles were formed and cuticlar layer was intergrated,basal nerve terminals were found. Meanwhile asso-ciated with Ap and ABR recovery of auditory func-tion. So, Hair cells regeneration played a great role in the recoverv of cochlea function.