国产C57和BALB/c小鼠年龄相关性听力损失的畸变产物耳声发射检测

Distortion Product Otoacoustic Emissions in Age-related Hearing Loss of C57 and BALB/c Inbred Mouse Strains

目的 通过对国产C5 7和BALB/c近交系小鼠不同日龄时DPOAE的检测 ,探讨其听力随年龄变化的趋势。方法 对不同日龄国产C5 7和BALB/c近交系小鼠进行DPOAE测试 ,设定初始音f1、f2 (f1/f2 =1.2 2 ) ,其强度L1=70dBSPL ,L2 =6 5dBSPL ,在频率 [(f1·f2 ) 0 .5]处采集数据并叠加处理。结果 国产C5 7和BALB/c近交系小鼠随年龄增大均出现听力下降 ,自 6 0日龄起DPOAE幅值在频率 4.0、6 .0、8.0kHz处均出现显著降低 (P <0 .0 1) ,随年龄增大有向低频发展的趋势。结论 国产C5 7和BALB/c近交系小鼠存在与年龄相关的听力损失 ,可以作为研究年龄相关性耳聋的动物模型。

Objective To assess the dynamic age-related hearing loss of inbred mouse C57 and BALB/c strains via distortion product otoacoustic emissions(DPOAE). Methods DPOAE levels were evaluated in C57 and BALB/c of 20,30,60,90,120,150,180 days old respectively,with the conditions that two pure tones,which stimulated the DPOAE,were at frequencies(f 1,f 2,f 1/f 2=1.22)and levels(L 1=70 dB SPL,L 2=65 dB SPL).Results DPOAE levels of C57 and BALB/c gradually decreased with age.From 60 days old,DPOAE levels of the two strains were dramatically decreased at 4.0,6.0,8.0 kHz( P < 0.01 ),furthermore,DPOAE levels trended to decrease at lower frequencies when C57 and BALB/cs getting older.Conclusion There were significant age-related hearing loss in C57 and BALB/c. C57 and BALB/c inbred mouse strains could be served as animal models of age-related hearing loss or presbycusis.