Astrocyte control of the cerebrovasculature
Astrocyte control of the cerebrovasculature
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DOI：
10.1002/glia.20543
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发表时间：
2007-09-01
期刊：
影响因子：
6.2
通讯作者：
MacVicar, Brian A.
中科院分区：
文献类型：
--
作者：
Gordon, Grant R. J.;Mulligan, Sean J.;MacVicar, Brian A.
脑血管直径的控制对于维持健康的脑功能至关重要，因为它是使脑血流量（CBF）与活跃神经元的代谢需求相匹配的关键。最近的研究表明，星形胶质细胞在脑血管直径的调节中起着关键作用，并且有几种分子途径可以使星形胶质细胞引起这些变化。星形胶质细胞内Ca 2+的增加通过引起邻近血管的收缩和扩张而在血管扩张反应中表现出二分法。在星形胶质细胞中，Ca 2+敏感磷脂酶A（2）（PLA（2））产生花生四烯酸（AA）已被证明是收缩和扩张机制的共同点。收缩由AA转化为20-羟基二十碳四烯酸（20-HETE）引起，扩张由前列腺素E-2（PGE（2））或环氧二十碳三烯酸（EET）产生，一氧化氮（NO）的水平似乎决定了这两种途径中的哪一种被招募。此外，星形胶质细胞端足中Ca 2+激活的K+通道的激活和K+的外排也被认为通过平滑肌细胞（SMCS）的超极化和松弛来改变血管张力。广泛的推定途径表明，需要更多的工作来澄清星形胶质细胞在不同细胞条件下对血管动力学的贡献。尽管如此，很明显，星形胶质细胞是重要的，虽然复杂的CBF调节。(C)2007 Wiley-Liss，Inc.
The control of cerebral vessel diameter is of fundamental importance in maintaining healthy brain function because it is critical to match cerebral blood flow (CBF) to the metabolic demand of active neurons. Recent studies have shown that astrocytes are critical players in the regulation of cerebral blood vessel diameter and that there are several molecular pathways through which astrocytes can elicit these changes. Increased intracellular Ca2+ in astrocytes has demonstrated a dichotomy in vasomotor responses by causing the constriction as well as the dilation of neighboring blood vessels. The production of arachidonic acid (AA) in astrocytes by Ca2+ sensitive phospholipase A(2) (PLA(2)) has been shown to be common to both constriction and dilation mechanisms. Constriction results from the conversion of AA to 20-hydroxyeicosatetraenoic acid (20-HETE) and dilation from the production of prostaglandin E-2 (PGE(2)) or epoxyeicosatrienoic acid (EET) and the level of nitric oxide (NO) appears to dictate which of these two pathways is recruited. In addition the activation of Ca2+ activated K+ channels in astrocyte endfeet and the efflux of K+ has also been suggested to modify vascular tone by hyperpolarization and relaxation of smooth muscle cells (SMCS). The wide range of putative pathways indicates that more work is needed to clarify the contributions of astrocytes to vascular dynamics under different cellular conditions. Nonetheless it is clear that astrocytes are important albeit complicated regulators of CBF. (C) 2007 Wiley-Liss, Inc.