Regulation of sodium transport in the inner ear.
Regulation of sodium transport in the inner ear.
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DOI：
10.1016/j.heares.2011.05.003
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发表时间：
2011-10
期刊：
影响因子：
2.8
通讯作者：
Marcus, Daniel C.
中科院分区：
文献类型：
--
作者：
Kim, Sung Huhn;Marcus, Daniel C.
由于毛细胞的转导通道是阳离子通透性的，而不是K+选择性的，因此必须控制内淋巴中的Na+浓度以维持毛细胞的功能。毛细胞胞浆中Na+的泛滥或波动预计会导致细胞功能障碍、听力损失和眩晕。本文简要介绍了已知的在内耳每个腔室，包括耳蜗囊、球囊、半规管和内淋巴囊的Na+稳态的细胞机制。Na+进入各个器官的内淋巴可能是通过被动扩散，但这些途径尚未被识别或表征。Na+的吸收由运输细胞顶端(内淋巴)膜上的守门人通道控制。高钠离子选择性上皮钠通道(ENaC)控制Reissner膜、黄斑囊外上皮、半规管导管上皮和内淋巴囊的吸收。ENAC的活性受许多信号通路的控制，但最显著的是通过糖皮质激素信号对膜上通道数量的基因组调节。前庭移行细胞和外沟上皮细胞顶膜上的非选择性阳离子通道介导Na+和副感觉性K+吸收。毛细胞中K+介导的转导电流也伴随着Na+通量，因为转导通道是非选择性的阳离子通道。所有这些细胞的阳离子吸收都是由细胞外的ATP通过顶端非选择性阳离子通道(P2X受体)来调节的。内淋巴囊中的异质性上皮细胞群被认为对Na+有多条吸收途径，调节途径包括糖皮质激素和嘌呤能激动剂。
Na+ concentrations in endolymph must be controlled to maintain hair cell function since the transduction channels of hair cells are cation-permeable, but not K+-selective. Flooding or fluctuations of the hair cell cytosol with Na+ would be expected to lead to cellular dysfunction, hearing loss and vertigo. This review briefly describes cellular mechanisms known to be responsible for Na+homeostasis in each compartment of the inner ear, including the cochlea, saccule, semicircular canals and endolymphatic sac. The influx of Na+into endolymph of each of the organs is likely via passive diffusion, but these pathways have not yet been identified or characterized. Na+ absorption is controlled by gate -keeper channels in the apical (endolymphatic) membrane of the transporting cells. Highly Na+-selective epithelial sodium channels (ENaC) control absorption by Reissner’s membrane, saccular extramacular epithelium, semicircular canal duct epithelium and endolymphatic sac. ENaC activity is controlled by a number of signal pathways, but most notably by genomic regulation of channel numbers in the membrane via glucocorticoid signaling. Nonselective cation channels in the apical membrane of outer sulcus epithelial cells and vestibular transitional cells mediate Na+ and parasensory K+ absorption. The K+-mediated transduction current in hair cells is also accompanied by a Na+ flux since the transduction channels are nonselective cation channels. Cation absorption by all of these cells is regulated by extracellular ATP via apical nonselective cation channels (P2X receptors). The heterogeneous population of epithelial cells in the endolymphatic sac is thought to have multiple absorptive pathways for Na+ with regulatory pathways that include glucocorticoids and purinergic agonists.
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影响因子：
3.7
作者：
Kim HM;Wangemann P
通讯作者：
Wangemann P
DOI：
10.1152/ajprenal.2001.280.2.f214
发表时间：
2001-02-01
影响因子：
4.2
作者：
Couloigner, V;Fay, M;Ferrary, E
通讯作者：
Ferrary, E
影响因子：
3.2
作者：
Crouch, JJ;Sakaguchi, N;Schulte, BA
通讯作者：
Schulte, BA
影响因子：
5.5
作者：
Kim, Sung Huhn;Kim, Kyunghee X.;Marcus, Daniel C.
通讯作者：
Marcus, Daniel C.
影响因子：
1.7
作者：
Andrews, James C.;Honrubia, Vicente
通讯作者：
Honrubia, Vicente