BACKGROUND Severe variations in osmotic pressure are significant contributors to critical patient morbidity and mortality and might also affect platelet volume. We aimed to investigate possible osmotic-induced changes in mean platelet volume (MPV) and their possible effects on platelet aggregation activity (PLAG). METHODS We induced experimental variations of serum osmolality in blood samples from healthy volunteers (heparinized whole blood, WB) and isolated platelets (Platelet Rich Plasma, PRP) by adding isotonic, hypertonic, and hypotonic solutions of saline/water (pH = 7.2-7.4). PLAG was tested in WB samples with Impedance Aggregometry (IA) and in PRP samples with Light Transmission Aggregometry (LTA) using three agonists Adenosine Diphosphate (ADP, 10 μΜ), Thrombin Receptor Activating Peptide (TRAP-6, 10 μΜ) and Arachidonic Acid (AA, 500 μΜ). Osmolality was either calculated using a formula or measured directly. RESULTS We found almost identical osmolalities in WB and PRP preparations. Osmotic stress did not produce significant changes in MPV. In IA testing the hypotonic challenge of WB preparations produced significant reductions at 50 % (p = 0.056) (95 % CI: 11.2-2.4, in Ohms) of ADP and at 31 % (p = 0.017) (95 % CI: 13.4-8.6, in Ohms) of TRAP-6 -induced PLAG respectively. In PRP we did not observe any variations in PLAG with LTA. CONCLUSIONS We conclude that in vitro hypotonic stress of WB samples has an inhibitory effect on the PAR-1 (TRAP-6 induced) pathway and on the P2Y12 (ADP induced) pathway and reflects a distinct in vivo effect of hypo-osmotic stress on WB human platelet preparations.

中文翻译：

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渗透压变化引起的血小板功能障碍的体外研究。

背景渗透压的严重变化是危重患者发病率和死亡率的重要因素，并且还可能影响血小板体积。我们的目的是研究渗透压引起的平均血小板体积（MPV）的可能变化及其对血小板聚集活性（PLAG）的可能影响。方法 我们通过添加等渗、高渗和低渗的生理盐水/水（pH = 7.2-7.4）溶液，诱导健康志愿者（肝素化全血，WB）和分离血小板（富血小板血浆，PRP）的血液样本中血清渗透压的实验变化。 ）。使用三种激动剂二磷酸腺苷（ADP，10 μM）、凝血酶受体激活肽（TRAP-6，10 μM）和花生四烯酸，通过阻抗聚集法（IA）在WB样品中以及通过光透射聚集法（LTA）在PRP样品中测试PLAG (AA，500μM)。渗透压可以使用公式计算或直接测量。结果 我们发现 WB 和 PRP 制剂的渗透压几乎相同。渗透压并未对 MPV 产生显着变化。在 IA 测试中，WB 制剂的低渗挑战导致 ADP 显着降低 50% (p = 0.056)（95% CI：11.2-2.4，单位为欧姆）和 31%（p = 0.017）（95% CI：13.4-分别为TRAP-6诱导的PLAG的8.6，以欧姆为单位。在 PRP 中，我们没有观察到 PLAG 与 LTA 的任何变化。结论 我们得出结论，WB 样品的体外低渗应激对 PAR-1（TRAP-6 诱导）途径和 P2Y12（ADP 诱导）途径具有抑制作用，并反映了低渗应激对 WB 的明显体内影响人血小板制剂。