Open and shut case for Rho A? The questions of when, where and how the small GTPase mediates the permeability of endothelial junctions.
Open and shut case for Rho A? The questions of when, where and how the small GTPase mediates the permeability of endothelial junctions.
复制标题
打开和关闭 Rho A 的外壳？
DOI：
10.1093/cvr/cvt174
复制
发表时间：
2013
影响因子：
10.8
通讯作者：
Huxley,VirginiaH
中科院分区：
文献类型：
--
作者：
Huxley,VirginiaH
It is incredible that current textbooks of Medical Physiology persist in describing the vascular endothelial lining as a passive barrier of finite permeability. Similarly, when the endothelium is observed to participate in vascular function it is treated as a homogenous population of cells possessing a limited number of signalling pathways that regulate the production of substrates that interact with neighbouring cells to regulate (or dysregulate) function. Instead, the barrier segregating flowing blood from metabolizing tissue is a complex structure composed of the endothelium with its associated basement membrane and surface glycocalyx, as well as the peripheral cells including pericytes, mast cells, and fibroblasts at the capillary level and varying coverage by smooth muscle cells in the venules and arterioles, respectively. 1 This heterogeneous structure responds constantly to changing physical and chemical stimuli to regulate fluid and solute movement between compartments acutely and chronically.It is important to also recognize that the basal barrier properties, the permeability of the microvessel wall to the spectrum of solutes and fluid in vivo, support maintenance of tissue homoeostasis with appropriate solute delivery and waste removal. These properties vary by organ, 2, 3 vessel type, 3 age, 2, 3 sex, 4 and disease state. 2 Only recently has it been recognized that the permeability of the endothelial barrier is also dynamic and not appropriately represented by the constant ‘k’in the Fick equation. 1, 3–5 Just as vascular—tone represents the balance between contractile and dilatory mechanisms in vascular smooth muscle, so too does basal endothelial permeability represent a state between ‘leaky’and ‘tight’.
