豚鼠内耳Na,K-ATP酶α亚基异构体的表达

Expression of α Subunit Isoforms of Na,K-ATPase in the Inner Ear of Guinea Pig

目的 研究豚鼠内耳组织中Na ,K -ATP酶α亚基三种异构体α1、α2 、α3 的表达及其意义。方法 用小鼠抗大鼠Na ,K -ATP酶α亚基异构体特异性单克隆抗体 ,采用免疫组化SP法观察豚鼠耳蜗、半规管、椭圆囊及球囊组织中Na ,K -ATP酶α亚基三种异构体的表达模式。结果 α1亚基异构体广泛分布于内耳组织的各个部位 ,特别是上皮细胞和螺旋神经节细胞中 ,α2 和α3 亚基异构体则主要分布于螺旋神经节细胞、Corti器及血管纹。结论Na,K -ATP酶亚基异构体在内耳不同部位的表达差异表明不同的内耳细胞转运Na+ 和K+ 的能力不同 。

Objective To investigate the distribution and its significance of α subunit isoforms of Na,K-ATPase in the inner ear of guinea pig.Methods The expression of α subunit isoforms of Na,K-ATPase in labyrinth was studied immunocytochemically with the specific mouse antibodies against the α 1?α 2 and α 3 subunits of rat Na,K-ATPase.Results The expression of Na,K-ATPase α subunit isoforms varied among different cell regions of the inner ear. The α 1 subunit isoform was widely distributed in almost all regions, and was most abundant in the stria vascularis, sensory cells of the crista ampullaris and macula of the saccule, and the spiral ganglion cells, while the α 2 and α 3 subunit isoforms were present primarily in the spiral ganglion cells,the organ of Corti and stria vascularis.Conclusion The differential expression of Na,K-ATPase subunit isoforms presumably reflects different K + and Na + transport capacities among inner ear cells which, working in concert, serve to maintain homeostasis in inner ear.