水杨酸钠对小鼠耳蜗单离外毛细胞Prestin分布的影响

The Effects of Sodium Salicylate on the Prestin Distribution in Single Outer Hair Cells of Cochlea Mice

目的探讨水杨酸钠对小鼠听性脑干反应(ABR)阈值和耳蜗外毛细胞动力蛋白(Prestin)分布的影响。方法将28只成年健康小鼠随机分为4组:生理盐水对照组(A组)、水杨酸钠4d组(B组)、水杨酸钠8d组(C组)、水杨酸钠16d组(D组)。水杨酸钠200mg/kg·d,经腹腔注射,采用美国TDT系统测量听性脑干反应(ABR)阈值,荧光显微镜下观察单离外毛细胞Prestin的分布。结果 1听功能检测显示:与A组比较,B组小鼠ABR阈值升高,但变化尚不显著(P>0.05);C组和D组小鼠ABR阈值明显提高,与A组比较有显著性差异(P<0.05);D组小鼠ABR阈值与C组比较有所降低,但无显著性差异(P>0.05)。2荧光显微镜下显示:A组单离外毛细胞侧膜和底部膜可见明显的Prestin抗体阳性染色,B、C、D组Prestin在外毛细胞膜上分布不均匀,主要分布在外毛细胞侧膜。B组底部细胞膜可见少量阳性染色,C、D组底部细胞膜少量或无Prestin的阳性染色。结论水杨酸钠致小鼠听力下降可能与其导致的外毛细胞底部膜Prestin表达异常有关。

Objective To investigate the effects of sodium salicylate on the auditory brainstem response （ABR） thresholds and dynein （Prestin） distribution in outer hair cells of cochlea mice. Methods 28 healthy adult mice were randomly divided into four groups. Group A： the saline control group;Group B：the sodium sa- licylate 4 days group; Group C： the sodium salicylate 8 days group;Group D： the sodium salicylate 16 days group. Sodium salicylate was injected by intraperitoneal injection（200mg/kg ~ d）. Auditory brainstem response thresholds were detected by the United States TDT system. The distribution of prestin was examined by fluores- cence microscopy, Results （~）Auditory function tests showed： the ABR thresholds of group B increased, but the change is not significant when compared with group A （P 〉 0.05 ） ; ABR thresholds of Group C and D were sig- nificantly levated, there was a significant difference （ P 〈 0.05 ） when compared with group A ; there was no sig- nificant difference between group C and group D （ P 〉 0.05 ）. （~）fluorescence microscope showed ： Group A, the membrane side and bottom of single outer hair cell can be seen clearly prestin antibody staining. B ,C ,D group, prestin uneven distributed in the outer hair cell membrane, mainly distributed in the side membrane of outer hair cells. Group B,the bottom membrane showed small amount staining. C, D group, the membrane bottom of outer hair cell showed little or no prestin positive staining. Conclusion Sodium salicylate induced mice hearing loss may be correlated with prestin abnormal expression in bottom membrane of outer hair cells.