Calpain在卡铂引起的耳蜗Ⅰ型传入神经系统损害中的作用

Effect of Calpain in carboplatin induced Type Ⅰ afferent neuron lesion in the cochlea

目的研究观察Ｃａｌｐａｉｎ在灰鼠耳蜗内的定位及其注射卡铂后不同时间的表现。方法应用免疫细胞化学方法在透射电镜下观察卡铂引起的耳蜗毛细胞及其传入神经系统中 Ｃａｌｐａｉｎ的活动变化。结果发现卡铂首先损坏耳蜗Ⅰ型传入神经的树突并伴有 Ｃａｌｐａｉｎ的破坏活动。结论卡铂引起的耳蜗 Ｉ型传入神经系统的早期破坏可能是由于细胞内形成的高钙浓度激活了Ｃａｌｐａｉｎ的活性，由此导致了Ｉ型传入神经原的蛋白质水解变性。

Objective To observe the location and activity of Calpain in the cochlea in normal and carboplatin treated chinchillas. Methods Calpain immunolabeling in normal and carboplatin treated chinchillas was observed under the transmission electron microscope. Results Carboplatin initially targets Type I afferent dendrites Conclusion Early destruction of Type Ⅰ afferents may be initiated by the rapid rise of intracellular calcium that activates Calpain leading to the proteolytic degradation of Type I neurons.