Maugeri Norma, Di Fabio Giovannina, Barbanti Miriam, de Gaetano Giovanni, Donati Maria Benedetta, Cerletti Chiara
Laboratory of Cell Biology and Pharmacology of Thrombosis, Research Laboratories, John Paul II Centre for High Technology Research and Education in Biomedical Sciences, Catholic University, Campobasso, Italy.
Thromb Haemost. 2007 Jun;97(6):965-73. doi: 10.1160/th06-12-0680.
Parnaparin, a low-molecular-weight heparin (LMWH), prevents platelet activation and interaction with polymorphonuclear leukocyte (PMN) in a washed cell system. The in-vitro effect of parnaparin was studied here on platelet-PMN aggregates formed with more physiologic approaches in whole blood, in parallel with unfractionated heparin and enoxaparin, another LMWH. Citrated blood from healthy subjects was stimulated: i) from passage through the "Platelet Function Analyzer" (PFA-100), a device that exposes blood to standardized high shear flow through collagen/ADP cartridges; ii) by collagen and ADP (2 and 50 mug/ml, respectively) added in combination under stirring in an aggregometer cuvette; iii) with recombinant Tissue Factor, to generate thrombin concentrations able to activate platelets without inducing blood clotting, or iv) the Thrombin Receptor Activating Peptide-6 (TRAP-6). Platelet P-selectin and platelet-PMN aggregates were measured by flow cytometry upon stimulation of blood. Fibrinogen binding to platelets and markers of PMN activation were also detected. Platelet P-selectin expression and platelet-PMN aggregate formation were induced in all four activation conditions tested. Parnaparin prevented in a concentration-dependent manner (0.3-0.8 IUaXa/ml) the expression of P-selectin and the formation of mixed aggregates, while the two reference heparin preparations had a much weaker effect. Platelet fibrinogen binding and PMN activation markers (fibrinogen binding, CD11b and CD40) were also prevented by parnaparin. These data extend in more physiological systems of platelet activation, the anti-inflammatory profile of parnaparin, previously reported in washed cells. The greater effect of parnaparin, as compared to the reference heparins, could be due to chemico-physical differences possibly unrelated to their anticoagulant effect.
帕肝素是一种低分子量肝素（LMWH），在洗涤细胞系统中可防止血小板活化及与多形核白细胞（PMN）相互作用。本研究在全血中采用更接近生理状态的方法，研究了帕肝素对血小板 - PMN聚集体的体外作用，并与普通肝素和另一种低分子量肝素依诺肝素进行了对比。对健康受试者的枸橼酸盐抗凝血进行如下刺激：i）通过“血小板功能分析仪”（PFA - 100），该设备使血液通过胶原/ ADP检测池暴露于标准化的高剪切流中；ii）在搅拌下于聚集仪比色杯中联合添加胶原和ADP（分别为2和50μg/ml）；iii）加入重组组织因子，以产生能够激活血小板而不诱导血液凝固的凝血酶浓度；或iv）加入凝血酶受体激活肽 - 6（TRAP - 6）。在血液受到刺激后，通过流式细胞术检测血小板P - 选择素和血小板 - PMN聚集体。还检测了纤维蛋白原与血小板的结合以及PMN活化标志物。在所测试的所有四种激活条件下均诱导了血小板P - 选择素表达和血小板 - PMN聚集体形成。帕肝素以浓度依赖性方式（0.3 - 0.8 IUaXa/ml）抑制P - 选择素表达和混合聚集体形成，而两种参比肝素制剂的作用则弱得多。帕肝素还可抑制血小板纤维蛋白原结合和PMN活化标志物（纤维蛋白原结合、CD11b和CD40）。这些数据在更多生理血小板激活系统中扩展了先前在洗涤细胞中报道的帕肝素的抗炎特性。与参比肝素相比，帕肝素的作用更强，这可能是由于化学物理差异，可能与其抗凝作用无关。
