auditory evaluation of klotho gene knock out (kl/kl) mouse

采用听性脑干反应（ABR）和耳蜗内电位（EP）检测方法，对klotho基因敲除（kl/kl）小鼠的听觉功能进行了评价。kl/kl小鼠的ABR和EP较野生小鼠明显下降，提示kl/kl小鼠存在感音神经性听力损失。klotho mRNA的RT-PCR分析表明，在耳蜗中没有klotho mRNA的表达。免疫组化结果显示，klotho蛋白在耳蜗组织中不表达。这些结果进一步证明，从其他组织分泌的klotho蛋白必须通过血液循环到达耳蜗，并在那里发挥其对正常听觉功能至关重要的生理作用。

Auditory function of klotho gene knock out (kl/kl) mouse was evaluated by measuring of auditory brainstem response (ABR) and endocochlear potential (EP). ABR and EP of kl/kl mouse was significantly deteriorated compared with those of wild mouse, suggesting that kl/kl mouse has sensorineural hearing loss. RT-PCR analysis of klotho mRNA indicdated that there was no expression of klotho mRNA in the cochlea. Immunohistochemical study also indicated that klotho protein was not expressed in the cochlear tissu. These results suggtest that klotho protein secreted from other tissues must reach to the cochlea via blood circulation and exert its physiological action there essential for normal auditory function.