Adsorption of proteins out of plasma onto glass from a separated flow.
Adsorption of proteins out of plasma onto glass from a separated flow.
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将血浆中的蛋白质从分离流吸附到玻璃上。
DOI：
10.1163/156856294x00545
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Leonard,EF
中科院分区：
文献类型：
--
作者：
Leduc,C;Depaola,N;Konath,S;Vroman,L;Leonard,EF
定量研究了流动分离对血浆蛋白质吸附的扰动。构建了一种仪器，使流动在标准显微镜载玻片的大约一半宽度上进行分离，并通过用黑氧化铁对载玻片进行染色来观察分离的流中和附近的蛋白质沉积模式。滑块安装在两个同心圆柱体之间建立的Couette流场的边缘，圆柱体的外部在旋转。滑块位于固定的内筒上，就在一根矩形棒的下游，这根棒导致水流分离。暴露于棒上游注入的稀浆后，取出玻片并用氧化物悬液染色。产生的可见图案通过摄像机扫描并进行分析，以得出可以量化的污渍密度的相对值。氧化模式表明，与下游更远的地方相比，蛋白质在分离流动区域的下游和下游沉积到玻片上的速度较慢。当剪切速率为6.61 S~(-1)，对应于分离流点上方1.32 cm S~10.2 cm的速度时，在3~30min的范围内，除10~11min外，蛋白质的总吸附量随暴露时间的延长而增加，而在10~11min时，所有数据都呈现暂时的下降。在校准实验中，氧化物未能附着在暴露于纯化白蛋白的玻片上，但大量附着于暴露于纯化纤维蛋白原的玻片上。这些结果表明，血浆暴露后的氧化模式主要是由于纤维蛋白原，分离流动实验中暂时的减少是由于纤维蛋白原被较少染色的蛋白质、推测是高分子激动素和XII因子所取代。这项研究产生了定量的信息，证实了较少控制和非定量的早期发现。它证实了这样的假设，即在分离的流动区域，从稀浆到玻璃表面的蛋白质沉积顺序被延迟。
Perturbations in the adsorption of plasma proteins caused by flow separation were studied quantitatively. An instrument was constructed that causes flow to separate over approximately half the width of a standard microscope slide and the pattern of protein deposition in and near the separated flow was observed by staining the slide with black iron oxide. The slide was mounted at the edge of a Couette flow field established between two concentric cylinders, the outer of which was rotating. The slide was located on the stationary, inner cylinder just downstream of a rectangular bar that causes the flow to separate. After exposure to dilute plasma injected upstream of the bar, the slide was removed and stained with oxide suspension. The resulting, visible pattern was scanned through a video camera and analyzed to yield relative values of stain density that could be quantified. The oxide patterns suggest that proteins were deposited onto the slide less rapidly in and just downstream of the separated flow region than farther downstream. At a shear rate of 6.61 s-1, corresponding to a velocity of 1.32 cm s-10.2 cm above the point of flow separation, overall amounts of adsorbed proteins increased with exposure time in the range 3-30 min with the exception of a period from 10 to 11 min when all data show a temporary decrease. In calibration experiments, oxide failed to adhere to slides exposed to purified albumin but adhered copiously to slides exposed to purified fibrinogen. These results suggest that the oxide patterns following plasma exposure are attributable primarily to fibrinogen and that the temporary decrease in the separated flow experiments is attributable to the displacement of fibrinogen by a less stainable protein, conjecturally high molecular weight kininogen and factor XII. This study yields quantitative information confirming earlier findings that were less controlled and non-quantitative. It confirms the hypothesis that the sequence of protein deposition from dilute plasma to glass surfaces is delayed in regions of separated flow.