Toth K, Wenby R B, Meiselman H J
First Department of Medicine, Division of Cardiology, University of Pecs School of Medicine, Pecs, Hungary.
Biorheology. 2000;37(4):301-12.
Previous reports have suggested that non-ionic poloxamer surfactants of appropriate molecular mass and composition can reduce red blood cell (RBC) aggregation in whole blood and in RBC-plasma suspensions. We have thus evaluated this phenomenon for RBC aggregated by several water-soluble polymers, using poloxamer 188 (P188), a non-ionic, tri-block molecule (total molecular mass of 8.40 kDa, 80% polyoxyethylene). Human RBC were washed, then re-suspended in isotonic solutions of dextran 70 (70.3 kDa), dextran 500 (476 kDa), PVP (360 kDa) or P-L-GLU (61.2 kDa); density-separated RBC were also studied. RBC aggregation was quantitated via a computerized Myrenne Aggregometer (extent, strength) and by the Microscopic Aggregation Index (MAI) method. Over the range of 0.5 to 5 mg/ml, poloxamer 188 inhibited both the extent and strength of aggregation in a dose-dependent manner, with the magnitude of the decrease related to polymer type (e.g., at 5 mg/ml, 62% decrease for dextran 70 vs. 14% decrease for P-L-GLU); MAI results with dextran 70 also showed a dose-dependent decrease. Poloxamer 188 at 5 mg/ml was more effective with younger, less-dense cells. Based upon the depletion model for polymer-induced aggregation, these findings suggest that poloxamer 188 acts by penetrating the depletion layer near the glycocalyx, thereby reducing the osmotic gradient between the intercellular gap and the suspending medium. Regardless of the specific mechanism(s) of action, poloxamers appear to offer interesting approaches for future basic science and clinical studies, and thus the possibility for greater insight into RBC aggregation.
先前的报告表明，具有适当分子量和组成的非离子型泊洛沙姆表面活性剂可以减少全血以及红细胞-血浆悬浮液中红细胞（RBC）的聚集。因此，我们使用泊洛沙姆188（P188）（一种非离子型三嵌段分子，总分子量为8.40 kDa，80%为聚氧乙烯），对几种水溶性聚合物聚集的红细胞的这一现象进行了评估。将人红细胞洗涤后，再重悬于葡聚糖70（70.3 kDa）、葡聚糖500（476 kDa）、聚乙烯吡咯烷酮（PVP，360 kDa）或聚-L-谷氨酸（P-L-GLU，61.2 kDa）的等渗溶液中；还研究了密度分离的红细胞。通过计算机化的Myrenne血细胞聚集仪（程度、强度）和显微镜聚集指数（MAI）方法对红细胞聚集进行定量。在0.5至5 mg/ml的范围内，泊洛沙姆188以剂量依赖性方式抑制聚集的程度和强度，降低幅度与聚合物类型有关（例如，在5 mg/ml时，葡聚糖70降低62%，而P-L-GLU降低14%）；葡聚糖70的MAI结果也显示出剂量依赖性降低。5 mg/ml的泊洛沙姆188对较年轻、密度较小的细胞更有效。基于聚合物诱导聚集的耗尽模型，这些发现表明泊洛沙姆188通过穿透糖萼附近的耗尽层起作用，从而降低细胞间隙与悬浮介质之间的渗透梯度。无论具体的作用机制如何，泊洛沙姆似乎为未来的基础科学和临床研究提供了有趣的方法，因此有可能更深入地了解红细胞聚集。
