An inwardly rectifying K+ channel, Kir4.1, expressed in astrocytes surrounds synapses and blood vessels in brain
An inwardly rectifying K+ channel, Kir4.1, expressed in astrocytes surrounds synapses and blood vessels in brain
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DOI：
10.1152/ajpcell.2001.281.3.c922
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发表时间：
2001-09-01
影响因子：
5.5
通讯作者：
Kurachi, Y
中科院分区：
文献类型：
--
作者：
Higashi, K;Fujita, A;Kurachi, Y
胶质细胞表达向内纠偏的K+ (Kir)通道，在细胞外K+的缓冲中起关键作用。Kir4.1是迄今为止唯一显示在脑胶质细胞中表达的Kir通道。我们用特异性抗体检测了Kir4.1在大鼠脑中的分布。Kir4.1免疫染色在脑内分布广泛，但不弥漫性。嗅球肾小球层、小脑伯格曼神经胶质、室管膜、硬脑膜等部分区域活性较强，而胼胝体白质、小脑脚等部分区域活性较弱。在嗅球中，大约一半的胶质纤维酸性蛋白阳性星形胶质细胞中以分散的方式检测到Kir4.1免疫反应性。免疫电镜检查显示，在包裹突触和血管的星形胶质细胞突起上富含Kir4.1通道。这些数据表明，Kir4.1在有限的脑星形胶质细胞中表达，并可能在胶质细胞K+缓冲作用中发挥特定作用。
Glial cells express inwardly rectifying K+ (Kir) channels, which play a critical role in the buffering of extracellular K+. Kir4.1 is the only Kir channel so far shown to be expressed in brain glial cells. We examined the distribution of Kir4.1 in rat brain with a specific antibody. The Kir4.1 immunostaining distributed broadly but not diffusely in the brain. It was strong in some regions such as the glomerular layer of the olfactory bulb, the Bergmann glia in the cerebellum, the ependyma, and pia mater, while little activity was detected in white matter of the corpus callosum or cerebellar peduncle. In the olfactory bulb, Kir4.1 immunoreactivity was detected in a scattered manner in about one-half of the glial fibrillary acidic protein-positive astrocytes. Immunoelectron microscopic examination revealed that Kir4.1 channels were enriched on the processes of astrocytes wrapping synapses and blood vessels. These data suggest that Kir4.1 is expressed in a limited population of brain astrocytes and may play a specific role in the glial K+-buffering action.