Microvessels of the chick chorioallantoic membrane uniformly restrict albumin extravasation during angiogenesis and endothelial cytodifferentiation
Microvessels of the chick chorioallantoic membrane uniformly restrict albumin extravasation during angiogenesis and endothelial cytodifferentiation
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DOI：
10.1016/s0040-8166(97)80003-1
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发表时间：
1997-06-01
期刊：
影响因子：
2.6
通讯作者：
DeFouw, DO
中科院分区：
文献类型：
--
作者：
Cruz, A;Rizzo, V;DeFouw, DO
本研究旨在评估鸡绒毛膜尿囊膜（CAM）在内皮屏障功能建立期间（第4.5 - 6.0天）、正常发育快速阶段（第10天）和内皮细胞分化开始后（第14天）白蛋白在微血管内皮中的外渗情况。在显微注射异硫氰酸荧光素（FITC）偶联的鸡血清白蛋白（CSA）后，采用活体荧光共聚焦显微镜和视频密度仪对无壳培养中的CAM制剂进行了评价。在每个观察到的时间阶段，CAM前毛细血管、毛细血管和后毛细血管的FITC-CSA外渗均可忽略不计。由于内皮糖萼赋予净负的管腔电荷，CSA通过相互电荷排斥传输的阻抗也被评估。因此，在CAM微血管中预先注入硫酸鱼精蛋白（100 μ l/ml）以中和负电荷。然而，FITC-CSA的间质积累仍然可以忽略不计。因此，在CAM正常发生过程中，紧密的连接间隙和质乳泡的缺乏可能是观察到的白蛋白限制的主要形态学相关因素。此外，与大多数血管生成内皮相比，正生CAM内皮对大分子具有更强的限制性屏障。
The present study sewed to evaluate extravasation of albumin across the microvascular endothelium of the chick chorioallantoic membrane (CAM) during the establishment of endothelial barrier functions (days 4.5 to 6.0), during a rapid phase of normigenesis (day 10), and after initiation of endothelial cytodifferentiation (day 14). CAM preparations in shell-less cultures were evaluated by intravital fluorescence confocal microscopy and videodensitometry after microinjections of chicken serum albumin (CSA) conjugated to Fluorescein isothiocyanate (FITC) (1% in Avian Ringers). At each observed temporal stage, FITC-CSA extravasation from the CAM pre-capillaries, capillaries, and post-capillaries was uniformly negligible. Since the endothelial glycocalyx imparts a net negative luminal charge, impedance of CSA transport by mutual charge repulsion was also evaluated. Accordingly, CAM microvessels were pre-infused with protamine sulfate (100 mu l/ml) to neutralize the negative charge. However, interstitial accumulation of FITC-CSA remained negligible. Thus, the presence of tight junctional clefts and paucity of plasmalemmal vesicles during CAM normigenesis probably serve as the principal morphologic correlates to the observed albumin restriction. Further, the normigenic CAM endothelium presents a more restrictive barrier to macromolecules than that of most angiogenic endothelia.