Different vascular permeability between the sensory and secretory circumventricular organs of adult mouse brain
Different vascular permeability between the sensory and secretory circumventricular organs of adult mouse brain
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DOI：
10.1007/s00441-012-1421-9
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发表时间：
2012-08-01
影响因子：
3.6
通讯作者：
Miyata, Seiji
中科院分区：
文献类型：
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作者：
Morita, Shoko;Miyata, Seiji
血脑屏障(BBB)阻止循环分子自由进入大脑，并维持特殊的脑环境，以保护大脑免受血液衍生的生物活性和有毒分子的影响；然而，室周器官(CVO)具有开窗的血管系统。感觉性CVO的有窗血管系统包括终板血管器(OVLT)、穹隆下器(SFO)和最后区(AP)，使神经元和星形胶质细胞能够感知各种血浆分子并将其信息传递到其他脑区，而分泌型CVO中的血管系统(包括正中隆起(ME)和神经垂体(NH))允许神经末梢分泌许多肽进入血流。本研究表明低分子示踪剂异硫氰酸荧光素(FITC)和伊文思蓝(Evans Blue)在分泌型CVO和肾脏中的血管通透性高于感觉型CVO。另一方面，FITC标记的牛血清白蛋白和葡聚糖70000等高分子示踪剂在CVO中的血管通透性低于肾脏。低分子和高分子示踪剂的显著血管通透性也在弓状核观察到。这些数据表明，与感觉性CVO相比，分泌型CVO对低分子分子的血管通透性更高，这可能是因为大量的肽分泌到血流中。此外，高分子示踪剂在CVO中的血管通透性小于肾脏，表明CVO并非完全没有血脑屏障。
The blood-brain barrier (BBB) prevents free access of circulating molecules to the brain and maintains a specialized brain environment to protect the brain from blood-derived bioactive and toxic molecules; however, the circumventricular organs (CVOs) have fenestrated vasculature. The fenestrated vasculature in the sensory CVOs, including the organum vasculosum of lamina terminalis (OVLT), subfornical organ (SFO) and area postrema (AP), allows neurons and astrocytes to sense a variety of plasma molecules and convey their information into other brain regions and the vasculature in the secretory CVOs, including median eminence (ME) and neurohypophysis (NH), permits neuronal terminals to secrete many peptides into the blood stream. The present study showed that vascular permeability of low-molecular-mass tracers such as fluorescein isothiocyanate (FITC) and Evans Blue was higher in the secretory CVOs and kidney as compared with that in the sensory CVOs. On the other hand, vascular permeability of high-molecular-mass tracers such as FITC-labeled bovine serum albumin and Dextran 70,000 was lower in the CVOs as compared with that in the kidney. Prominent vascular permeability of low- and high-molecular-mass tracers was also observed in the arcuate nucleus. These data demonstrate that vascular permeability for low-molecular-mass molecules is higher in the secretory CVOs as compared with that in the sensory CVOs, possibly for large secretion of peptides to the blood stream. Moreover, vascular permeability for high-molecular-mass tracers in the CVOs is smaller than that of the kidney, indicating that the CVOs are not totally without a BBB.