【摘要】 目的探讨慢性氟中毒大鼠耳蜗毛细胞形态学的改变和听力损失的机制。方法借助畸变产物耳声发射(distortion product otoacoustic emissions,DPOAE)测试和扫描电镜技术,对60只大鼠进行了实验观察。结果DPOAE测试结果显示对照组与低氟组、高氟组8kHz反应幅值差异均有显著性(P<0.05),0.5、1、2、4kHz各组数据经统计学处理(P>0.05),无统计学意义。对照组耳蜗内、外毛细胞排列规则。低氟组的内、外毛细胞都有不同程度的损害,表现为静纤毛粘连、倒伏。高氟组内、外毛细胞的损害严重,出现明显的粘连、倒伏、融合,并可见散在的节段性缺失,以底圈明显。表皮板结构发生不同程度的病变,严重者表皮板穿孔,细胞内容物流出,形成气球样改变。结论慢性氟中毒明显影响听力,导致高频感音神经性耳聋,其损害机制可能是氟对耳蜗毛细胞的直接损害造成的。听功能损害的严重程度与氟中毒程度相关。更多还原

【Abstract】 Objective To study the ultrastructural characteristics of the fluorosis rat cochlea and explore the possible mechanism of hearing damage caused by chronic fluorosis. Methods Using distortion product otoacoustic emissions(DPOAE)and scanning electron microscopy the changes of auditory function and cochlear ultrastructure in 60 rats, which were divided into one control and two experimental (low- and high- dose fluoride) groups, were investigated. Results A decreased amplitude of DPOAE was detected at the 8 kHz frequency in the two experimental groups cornpared to the control group (P < 0.05), while there were no significant differences at other freqencies. Cochear hair cells of the control group were aligned regularly. Both inner and outer hair cells in the two experimental groups all suffered lesions to a various extent, and severer in the outer hair cells, presenting with stereocilia fusion or disarray. Lesions of the outer and inner hair cells in the high- dose fluoride group were more serious than those in the low- dose one, and sometimes developed ball- like lesions, cuticular plate ruptures and finally hair cell loss. Conclusion Cochlear hair cell damage caused by chronic fluorosis associated with high- frequency sensorineural hearing loss may be the major pathogenesis of fluorosis in the auditory system. The degree of the hearing loss is parallel to the level of fluorosis.更多还原