AGGREGATION AND DISAGGREGATION KINETICS OF HUMAN BLOOD-PLATELETS .2. SHEAR-INDUCED PLATELET-AGGREGATION
AGGREGATION AND DISAGGREGATION KINETICS OF HUMAN BLOOD-PLATELETS .2. SHEAR-INDUCED PLATELET-AGGREGATION
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DOI：
10.1016/s0006-3495(93)81079-8
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发表时间：
1993-07-01
影响因子：
3.4
通讯作者：
HELLUMS, JD
中科院分区：
文献类型：
--
作者：
HUANG, PY;HELLUMS, JD
在第一部分(Huang，P.Y.和J.D.Hellum)中，建立了一个用于分析血小板聚集动力学的群体平衡方程(PBE)数学模型。1993年。生物群落。约65：334-343)一套三篇论文。本文第二部分，研究了旋转粘度计均匀剪切应力场中的血小板聚集及其相关反应，并用该模型进行了解释。实验测定了在剪应力作用下，随着时间的推移，血小板聚集物的颗粒大小分布。无论是可逆形式(聚集和解聚)还是不可逆形式(非解聚)，PBE模型都能很好地符合实验结果。这一发现表明，在所研究的实验条件下，解聚过程只是次要的。在剪切诱导的血小板聚集过程中，只有一小部分的血小板碰撞会导致相关的血小板结合在一起。当剪切速率低于3000 S-1时，修正的碰撞效率近似为零。当切变率在3000 S-1以上时，切变率增大到约0.01，切变率为8000 S-1时。加入血小板化学激动剂可使碰撞效率提高数量级。剪切诱导的血小板聚集的碰撞效率在37摄氏度比24摄氏度低一个数量级。与基于单分散颗粒尺寸分布的早期模型相比，PBE模型给出了更准确的聚集动力学表示。
A population balance equation (PBE) mathematical model for analyzing platelet aggregation kinetics was developed in Part I (Huang, P. Y., and J. D. Hellums. 1993. Biophys. J 65: 334-343) of a set of three papers. In this paper, Part II, platelet aggregation and related reactions are studied in the uniform, known shear stress field of a rotational viscometer, and interpreted by means of the model. Experimental determinations are made of the platelet-aggregate particle size distributions as they evolve in time under the aggregating influence of shear stress. The PBE model is shown to give good agreement with experimental determinations when either a reversible (aggregation and disaggregation) or an irreversible (no disaggregation) form of the model is used. This finding suggests that for the experimental conditions studied disaggregation processes are of only secondary importance. During shear-induced platelet aggregation, only a small fraction of platelet collisions result in the binding together of the involved platelets. The modified collision efficiency is approximately zero for shear rates below 3000 s-1. It increases with shear rates above 3000 s-1 to about 0.01 for a shear rate of 8000 s-1. Addition of platelet chemical agonists yields order of magnitude increases in collision efficiency. The collision efficiency for shear-induced platelet aggregation is about an order of magnitude less at 37-degrees-C than at 24-degrees-C. The PBE model gives a much more accurate representation of aggregation kinetics than an earlier model based on a monodispersed particle size distribution.