Platelet activation in a circulating flow loop: combined effects of shear stress and exposure time
Platelet activation in a circulating flow loop: combined effects of shear stress and exposure time
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DOI：
10.1080/0953710031000092839
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发表时间：
2003-05-01
期刊：
影响因子：
3.3
通讯作者：
Bluestein, D
中科院分区：
文献类型：
--
作者：
Jesty, J;Yin, W;Bluestein, D
由于缺乏实时测定方法和低血小板活化潜能的循环系统，体外循环狭窄系统中血小板活化状态（PAS）的微小变化的测量一直存在问题。通过改良的凝血酶原酶测定法测量PAS，其中活化的血小板提供因子XA激活凝血酶原的必需辅因子。凝血酶原的化学修饰确保所产生的凝血酶虽然可测定，但不激活血小板。人血小板在环中循环，其中通过独立改变流速、粘度和暴露于剪切的时间来调节暴露于剪切应力。尽管血小板对不同应力条件的反应存在一些差异，但PAS直接随循环时间、剪切应力和暴露于剪切的时间而增加。结果表明，低水平的血小板活化引起的循环回路中的剪切应力可以定量评估在近实时的系统中的管几何形状。他们证实了以前在非循环系统中获得的结果，即血小板暴露于与血管系统中相同顺序的剪切条件会导致显著的血小板活化，并且这种活化取决于剪切应力和暴露时间。
Measurement of small changes in platelet activation state (PAS) in circulating stenotic systems in vitro has been problematic because of a paucity of real-time assay methods and circulation systems of low platelet-activating potential. PAS was measured by a modified prothrombinase assay in which activated platelets provide the essential cofactors in the activation of prothrombin by factor Xa. Chemical modification of the prothrombin ensures that the thrombin produced, while assayable, does not activate platelets. Human platelets were circulated in loops in which exposure to shear stress was adjusted by independently varying flow rate, viscosity, and the time of exposure to shear. Although with some differences in platelet response to different conditions of stress, the PAS directly increased with time of circulation, shear stress, and time of exposure to shear. The results show that low-level platelet activation caused by shear stress in a circulation loop can be quantitatively assessed in near-real time in a system of tube geometry. They confirm previous results obtained in non-circulating systems that exposure of platelets to shear conditions on the same order as found in the vasculature causes significant platelet activation, and that this activation is dependent on both shear stress and time of exposure.