宽频带白噪声暴露对巴马香猪和豚鼠听力损伤的影响

Effects of White Noise Exposure on Hearing in Bama Miniature Pigs and Guinea Pigs

目的通过120dB SPL宽频带白噪声对巴马香猪和豚鼠各进行单次3小时的暴露,观察比较该种噪声对两种模型动物听力损伤的特点,找到更适用于研究噪声性听力损伤的动物模型。方法选取8只6月龄ABR听阈正常的巴马香猪,和8只5~6周龄ABR听阈正常的豚鼠,设置4个ABR测听记录点:噪声暴露前,噪声暴露后即刻(P0)、1天(P1)、7天(P7)。全部测听结束后,取材制作耳蜗标本,进行扫描电镜观察形态。结果通过统计学分析,豚鼠组在120dB SPL宽频带白噪声暴露后即刻的ABR阈值与暴露1天的ABR阈值具有明显差异,具有统计学意义,而巴马香猪组则无明显统计学差异。豚鼠组在噪声暴露前和噪声暴露后7天的ABR阈值无明显统计学差异,而巴马香猪组却有明显的统计学差异。相对于豚鼠,巴马香猪耳蜗标本扫描电镜提示了更多的纤毛异常。结论120d B SPL宽频带白噪声暴露会对巴马香猪和豚鼠造成一定程度的听力损伤。其中巴马香猪较豚鼠表现更为明显的听力损失,且毛细胞出现了更多的病理改变,由此本研究表明在120d B SPL宽频带白噪声单次暴露3小时的条件下,巴马香猪是一个更适于白噪声与听力损伤的研究的动物模型,从而可以更好地为噪声性耳聋提供动物模型。

Objective To find a more suitable animal model for investigating the noise-induced hearing loss by comparing the effects of120dB SPL white noise exposure for three hours on the hearing in bama miniature pigs and guinea pigs.Methods Auditory brainstem response(ABR)in8bama miniature pigs and8guinea pigs with normal hearing was tested before exposure,immediately(P0),1day(P1)and7days(P7)after exposure.Cochlear specimens were observed using scanning electron microscopy.Results The ABR threshold showed a statistically significant difference between the immediate group and P1group in guinea pigs,but not in bama miniature pigs.There was a statistically significant difference between the immediate group and P7group in bama miniature pigs,but not in guinea pigs.Furthermore,the bama miniature pigs showed more severe cochlear hair cell damages than that in guinea pigs.Conclusions The bama miniature pig cochleae are more vulnerable to120dB SPL white noise exposure,with more profound hearing loss and more severe pathological changes.The results suggest that bama miniature pig could be a more suitable animal model for noise-induced hearing loss study.