Aarts P A, Heethaar R M, Sixma J J
Blood. 1984 Dec;64(6):1228-33.
Hematocrit and red cell size are important factors for the transport of blood platelets toward subendothelium in flowing blood. We report that red cell deformability also influences platelet transport. Red cell deformability was estimated with Couette-flow viscosimetry at a shear rate of 130 s-1 and expressed as a 'T' factor--a dimensionless parameter relating the relative viscosity and the hematocrit derived from the relationship: T = (1 - mu -0.4 rel)/H, where mu rel is the relative viscosity and H is the hematocrit. The normal value of T was within a narrow range (0.91 +/- 0.02). Treatment of normal red cells with isoxsuprine and chlorpromazine caused decreased rigidity and decreased T. Cholesterol loading and treatment with diamide increased rigidity and increased T. In vitro perfusion experiments in an annular perfusion system with everted human umbilical arteries were performed with perfusates to which such treated red blood cells were added to investigate their influence on platelet adherence to artery subendothelium. Platelet adherence was well correlated with red cell rigidity, with increased adherence at increased rigidity and vice versa. A change in T of 0.10 corresponded to a change in platelet adherence of approximately 50%. These effects were more pronounced at a wall shear rate of 1,800 s-1 than at 300 s-1.
血细胞比容和红细胞大小是影响流动血液中血小板向血管内皮细胞下转运的重要因素。我们报告红细胞变形性也会影响血小板的转运。采用库埃特流粘度测定法在剪切速率为130 s⁻¹ 时评估红细胞变形性，并将其表示为 “T” 因子 —— 一个无量纲参数，由相对粘度和血细胞比容的关系推导得出：T = (1 - μrel⁻⁰.⁴)/H，其中 μrel 是相对粘度，H 是血细胞比容。T 的正常值在一个狭窄范围内（0.91 ± 0.02）。用异舒普林和氯丙嗪处理正常红细胞会导致刚性降低和 T 值降低。胆固醇负载和用二酰胺处理会增加刚性并提高 T 值。在一个带有外翻人脐动脉的环形灌注系统中进行体外灌注实验，向灌注液中添加经上述处理的红细胞，以研究它们对血小板黏附于动脉内皮细胞下的影响。血小板黏附与红细胞刚性密切相关，刚性增加时黏附增加，反之亦然。T 值变化0.10 对应血小板黏附变化约 50%。这些效应在壁面剪切速率为 1800 s⁻¹ 时比在 300 s⁻¹ 时更明显。
