电离辐射对大鼠耳蜗外毛细胞Prestin蛋白表达影响的实验研究

目的探讨电离辐射下大鼠耳蜗外毛细胞Prestin蛋白表达的改变及意义。方法建立大鼠耳放射损伤模型,检测其听力复合动作电位（CAP）阈值及畸变产物耳声发射（DPOAEs）幅值,验证其电离辐射晚期感音神经性耳聋（SNHL）的发生。提取大鼠耳蜗组织mRNA及蛋白,荧光实时定量PCR检测耳蜗Prestin蛋白mRNA水平的表达,以及Western杂交检测Prestin蛋白水平的表达。结果成功建立了电离辐射晚期SNHL大鼠模型,其耳蜗Prestin蛋白无论是mRNA表达水平还是蛋白表达水平均较未照射组明显降低。结论放疗晚期感音神经性耳聋的发生机制可能与电离辐射导致内耳外毛细胞Prestin蛋白的表达异常有关。

Effect of ionizing radiation on the Prestin expression in the rat cochlear outer hair cells

Objective To investigate the effect of ionizing radiation on the expression level of Prestin protein in rat cochlear outer hair cells and its significance. Methods We established a rat model of radiation injury on the ear, and then detected its hearing compound action potential （CAP） thresholds and distortion product otoacoustic emissions （DPOAEs） amplitude to verify the sensorineural hearing loss （SNHL） after ionizing radiation.After extracting the total mRNA and protein of rat cochlea,we detected the Prestin gene expression level by fluorescence real-time quantitative PCR,and its Protein expression level by Western blotting. Results We successfully established a rat model of SNHL after radiation. Compared with unirradiated control group,the Prestin expression both in mRNA and protein levels were decreased significantly. Conclusion The mechanism of sensorineural hearing loss after radiotherapy maybe correlated with Prestin protein expression abnormalities of the outer hair cells in the inner ear after ionizing radiation.