豚鼠壶腹嵴感觉细胞损伤与修复过程对前庭功能的影响

Effect of the damage and repair of crista ampuilaris on vestibular function in guinea pig inner ear

为观察庆大霉素损伤后豚鼠壶腹感觉细胞损伤与修复对前庭功能的影响,探讨前庭感觉上皮细胞损伤后自发修复与前庭功能恢复的关系。实验组动物连续12天皮下注射125mg/kg 庆大霉素,应用正旋摆动实验和旋转实验连续观察前庭功能的变化,结合不同存活时间动物水平半规管壶腹嵴的扫描电镜观察和半薄切片壶腹嵴顶部不同类型毛细胞的定量分析。结果示:停药第22天的10只动物中有4只动物前庭功能有一定程度的恢复.但仍有明显前庭功能低下,其中两只存活至100天。前庭功能无进一步恢复。停药后第1、3天,Ⅰ型毛细胞明显减少。停药后第22天、100天.Ⅰ型毛细胞数目仍然很少,Ⅱ型毛细胞明显增多(其中包括在形态上类似Ⅱ型毛细胞的新生的感觉细胞)。将正常和停药后不同时间豚鼠两种类型毛细胞数量变化与相对应半规管功能进行相关分析,水平半规管壶腹嵴顶部Ⅰ型毛细胞数与豚鼠半规管功能呈显著正相关,而Ⅱ型毛细胞数与半规管功能无显著相关性。本研究不能说明庆大霉素损伤后再生修复的前庭感觉细胞具有恢复正常生理功能的作用。

The vestibular function change and repair of crista ampullaris were investigated af- ter treatment with gentamicin (125mg/kg,12 days) on guinea pigs.Sinusidal swing test and rotation test were used to examine the vestibular function of the experimental animals.The injury and repair of the lateral crista apmullaris were observed by scanning electron microscopy and semi-thin sections,and the numbers of type Ⅰ hair cell,type Ⅱ hair cell and supporting cell were counted respectively.At 22 days after treatment, vestibular function of 4/10 animals showed recovery slightly;there was no further im- provement on 2 of them who were alive up to 100 days after treatment.At 1 and 3 days after treatment,the number of type Ⅰ hair cells was reduced obviously.At 22 and 100 days after treatment,the number of type Ⅱ hair cell was increased clearly (including the renewed cells with morphology similar to that of type Ⅱ hair cell).The relationship between the number of different types of hair cells and the vestibular function during different periods of time after treatment was analyzed.It is obvious that there is rela- tionship between the number of type Ⅰ hair cell in the apex of the crista and vestibular function.The result did not show that the renewed sensory cells actully re- cover functioally following crista ampullaris injury by gentamicin.