神经生长因子在小鼠耳蜗中的表达分布及年龄相关性变化

目的探讨神经生长因子(NGF)在小鼠耳蜗中的表达分布与年龄的相关性变化。方法选取5、7月龄的快速老化小鼠亚系8(SAMP8)作为实验组,而同龄抗快速老化小鼠亚系1(SAMR1)作为对照组。分别观察其耳蜗中NGF免疫组化染色及增龄性变化情况。结果在小鼠耳蜗中,NGF在螺旋神经节细胞、内外毛细胞、听神经纤维及血管纹中均有表达,且螺旋神经节细胞及内外毛细胞为主要表达部位。耳蜗螺旋神经节细胞及内外毛细胞NGF免疫组化染色平均光密度值:NGF蛋白在不同月龄快速老化小鼠耳蜗组织中螺旋神经节细胞及毛细胞均有表达,第5、7月龄SAMP8小鼠耳蜗螺旋神经节细胞及毛细胞中的NGF蛋白表达较同龄SAMR1小鼠明显降低(P<0.05)。结论 NGF蛋白在小鼠耳蜗中有表达并且表达水平随着小鼠年龄增长而降低,说明NGF蛋白可能与维持耳蜗的功能状态有关。

Distribution and age-related changes of nerve growth factor in the cochlea of mouse

Objective To investigate the distribution and the age-related of NGF changes in the cochlea of mouse.Methods Distribution in the cochlea and age-related expression of NGF protein in the cochlea spiral ganglion cell and hair cell were studied in SAMP8 mice of 5,7 months.Normal aging senescence accelerated mouse/resistance 1(SAMR1) mice served as the control groups.Results NGF expression was observed in inner and outer hair cell,spiral ganglion cell,auditory nerve fibers and stria vasculari.The optical density of NGF immunohistochemical staining in the mouse,cochlea spiral ganglion cell and hair cell:There were NGF protein expressed in the cochlea of the senescence accelerated mouse throughout the development.Compared with the SAMR1,the SAMP8 at 5,7 months developed a significant descend(P<0.05).Conclusion NGF expresses in the cochlea of mouse and the expression level changes with age.This indicates that NGF protein probably has relationship with maintaining functional status of the cochlea.