Hydrodynamic effects and receptor interactions of platelets and their aggregates in linear shear flow.
Hydrodynamic effects and receptor interactions of platelets and their aggregates in linear shear flow.
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线性剪切流中血小板及其聚集体的流体动力学效应和受体相互作用。
DOI：
10.1016/s0006-3495(97)78311-5
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发表时间：
1997
影响因子：
3.4
通讯作者：
Diamond,SL
中科院分区：
文献类型：
--
作者：
Tandon,P;Diamond,SL
我们通过考虑二体碰撞流体力学、血小板激活和受体生物学，模拟了线性剪切流动中的血小板聚集。将血小板及其聚集体视为具有DLVO相互作用(psi=-15 mV，Hamaker常数=10(-19)J)的不等尺寸球体，详细的流体力学提供了碰撞血小板周围的流场。进行了轨迹计算，得到了远上游截面积，通过该区域的颗粒通量提供了碰撞频率。如果通过纤维蛋白原交叉桥接血小板表面的GPIIb/IIIa受体，只有一小部分通过剪切流聚集在一起的血小板能够结合在一起。这一比例是通过使用贝尔(Bell，G.I.1979)的形式主义对受体介导的聚集进行建模来计算的。多价配体介导的细胞间黏附的理论模型。细胞生物物理学。1：133-147)，其中键形成的前向速率决定了碰撞期间的聚集，并由受体的侧向结合的扩散限制速率乘以有效性因子Eta来估计，以给出表观速率。对于ETa=0.0178，我们计算出具有50,000个受体/血小板的总效率(包括受体结合和流体动力学效应)：G=41.9 S(-1)为0.206，G=335 S(-1)为0.05，G=1920 S(-1)为0.0086，这些值与通过试管中的初始血小板单核细胞消耗率所确定的效率相一致。根据我们的分析，我们预测键形成的速度约为每毫秒0.1925个键/微米~2，这大约比扩散限制的缔合速度慢50倍。这一ETA值也与未激活的血小板在低切变率下的胶体稳定性一致。纤维蛋白原被计算为在低切变率下非常有效地介导聚集，但在高切变率下则不能。虽然二次碰撞(类似轨道的轨迹)只占碰撞总数的一小部分，但它们在高剪切率下变得重要(>；750 S(-1))，因为这些碰撞是唯一提供足够时间导致纤维蛋白原介导的成功聚集体形成的碰撞。整个方法提供了Smoluchowski碰撞核的流体动力学和受体校正，并首次估计了血小板纤维蛋白原-GPIIb/IIIa交叉桥的ETA。我们还预测，二次碰撞扩大了纤维蛋白原介导成功聚集的剪切速率范围。
We have modeled platelet aggregation in a linear shear flow by accounting for two body collision hydrodynamics, platelet activation and receptor biology. Considering platelets and their aggregates as unequal-sized spheres with DLVO interactions (psi(platelet) = -15 mV, Hamaker constant=10(-19) J), detailed hydrodynamics provided the flow field around the colliding platelets. Trajectory calculations were performed to obtain the far upstream cross-sectional area and the particle flux through this area provided the collision frequency. Only a fraction of platelets brought together by a shearing fluid flow were held together if successfully bound by fibrinogen cross-bridging GPIIb/IIIa receptors on the platelet surfaces. This fraction was calculated by modeling receptor-mediated aggregation using the formalism of Bell (Bell, G. I. 1979. A theoretical model for adhesion between cells mediated by multivalent ligands. Cell Biophys. 1:133–147) where the forward rate of bond formation dictated aggregation during collision and was estimated from the diffusional limited rate of lateral association of receptors multiplied by an effectiveness factor, eta, to give an apparent rate. For a value of eta=0.0178, we calculated the overall efficiency (including both receptor binding and hydrodynamics effects) for equal-sized platelets with 50,000 receptors/platelet to be 0.206 for G=41.9 s(-1), 0.05 for G=335 s(-1), and 0.0086 for G=1920 s(-1), values which are in agreement with efficiencies determined from initial platelet singlet consumption rates in flow through a tube. From our analysis, we predict that bond formation proceeds at a rate of approximately 0.1925 bonds/microm2 per ms, which is approximately 50-fold slower than the diffusion limited rate of association. This value of eta is also consistent with a colloidal stability of unactivated platelets at low shear rates. Fibrinogen was calculated to mediate aggregation quite efficiently at low shear rates but not at high shear rates. Although secondary collisions (an orbitlike trajectory) form only a small fraction of the total number of collisions, they become important at high shear rates (>750 s(-1)), as these are the only collisions that provide enough time to result in successful aggregate formation mediated by fibrinogen. The overall method provides a hydrodynamic and receptor correction of the Smoluchowski collision kernel and gives a first estimate of eta for the fibrinogen-GPIIb/IIIa cross-bridging of platelets. We also predict that secondary collisions extend the shear rate range at which fibrinogen can mediate successful aggregation.
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影响因子：
3.4
作者：
HUANG, PY;HELLUMS, JD
通讯作者：
HELLUMS, JD
DOI：
10.1016/s0021-9258(18)42050-9
发表时间：
1992-08
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
J. Weisel;C. Nagaswami;G. Vilaire;J. Bennett
通讯作者：
J. Weisel;C. Nagaswami;G. Vilaire;J. Bennett
血小板糖蛋白 IIb-IIIa（α IIb beta 3 整合素）在异源细胞上赋予纤维蛋白原和激活依赖性聚集。
影响因子：
20.3
作者：
Frojmovic,MM;O'Toole,TE;Plow,EF;Loftus,JC;Ginsberg,MH
通讯作者：
Ginsberg,MH
影响因子：
3.4
作者：
Taylor, AD;Neelamegham, S;Simon, SI
通讯作者：
Simon, SI
哺乳动物血小板聚集中的长程相互作用。
影响因子：
3.4
作者：
M. Frojmovic;K. Longmire;T. V. D. van de Ven
通讯作者：
T. V. D. van de Ven