DOES THE RELEASE OF POTASSIUM FROM ASTROCYTE ENDFEET REGULATE CEREBRAL BLOOD-FLOW
DOES THE RELEASE OF POTASSIUM FROM ASTROCYTE ENDFEET REGULATE CEREBRAL BLOOD-FLOW
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DOI：
10.1126/science.3616619
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发表时间：
1987-08-21
期刊：
影响因子：
56.9
通讯作者：
NEWMAN, EA
中科院分区：
文献类型：
--
作者：
PAULSON, OB;NEWMAN, EA
脑内神经元活动的局部增加导致血管扩张和局部脑血流量增加。已知细胞外钾浓度的增加会扩张脑小动脉。最近的研究表明，由活跃的神经元释放的钾通过星形胶质细胞运输，并从它们的末足释放到血管上。大脑中钾动力学的计算机模拟结果表明，钾从星形胶质细胞末足的释放比钾通过细胞外空间的扩散更快地将血管周围的钾浓度提高到更高的水平，特别是当钾增加的部位距离血管壁有一定距离时。基于这一发现，有人提出，钾从星形胶质细胞endfeet的释放起着重要的作用，在调节区域脑血流量响应神经元活动的变化。
Local increases in neuronal activity within the brain lead to dilation of blood vessels and to increased regional cerebral blood flow. Increases in extracellular potassium concentration are known to dilate cerebral arterioles. Recent studies have suggested that the potassium released by active neurons is transported through astrocytic glial cells and released from their endfeet onto blood vessels. The results of computer simulations of potassium dynamics in the brain indicate that the release of potassium from astrocyte endfeet raises perivascular potassium concentration much more rapidly and to higher levels than does diffusion of potassium through extracellular space, particularly when the site of a potassium increase is some distance from the vessel wall. On the basis of this finding, it is proposed that the release of potassium from astrocyte endfeet plays an important role in regulating regional cerebral blood flow in response to changes in neuronal activity.