水杨酸对prestin无表达小鼠耳蜗噪声性损伤的作用

Effect of sodium salicylate on acoustic injury in prestin knockout mice

目的探讨水杨酸对prestin无表达小鼠耳蜗噪声性损伤的保护作用。方法以出生20-28d的prestin无表达小鼠30只为研究对象，分为A组（噪声暴露前单次注射水杨酸10只）、B组（噪声暴露前单次注射生理盐水10只）和C组（空白对照组10只）。对比观察各组小鼠处理后不同时刻听性脑于反应（auditory brainstem response，ABR）阈值、基底膜扫描和透射电镜情况。结果噪声暴露后第1天和第8天，A，B两组小鼠ABR阈值均较C组显著升高，但两组间差异无统计学意义（均P〉0．05）。噪声暴露后第8天，A，B两组小鼠扫描电镜观察均可见噪声损伤表现，差异不明显；而透射电镜显示B组外毛细胞胞浆内出现明显空泡化改变。结论噪声暴露前给予水杨酸干预对prestin无表达小鼠耳蜗噪声性损伤具有轻微保护作用，这种保护作用主要反映在形态学上，并在噪声损伤后期更易显现出来。

Objective To study the effect of sodium salicylate on acoustic injury in prestin knock-out mice.Methods Thirty prestin knock-out mice aged from 20 to 28 days were divided into group A （ single I. P. salicylate before noise exposure）, group B （single I. P. normal saline before noise exposure） and group C （without noise exposure and I. P. salicylate）. Dynamic changes of ABR thresholds were monitored. After final physiological examination, the cochleae were prepared for morphological examination by scanning and transmission electron microscopy. Results Mean thresholds of ABRs in group A and B were all elevated significantly compared with that in group C. But there was no difference between group A and group B（ P 〉0.05）. On the 8th day, there was no difference in morphological damage between the two groups by scanning electron microscopy. But vacuoles in outer hair cells was seen more significant in group B than in group A by transmission electron microscopy. Conclusions Sodium salicylate injection before noise exposure can mildly alleviate the morphological change induced lw acoustic injury to cochlea in Drest;n knock-out mice. This protection was more obvious at late phase after noise exposure.