van Wyk V, Heyns A D
South African Medical Research Council Blood Platelet Research Unit, Department of Haematology, University of the Orange Free State, Bloemfontein.
Thromb Res. 1990 Feb 15;57(4):601-9. doi: 10.1016/0049-3848(90)90077-p.
We evaluated the suitability of low molecular weight (LMW) heparin as an anticoagulant for in vitro platelet function tests in 11 normal volunteers. Results with citrated platelets were considered as the standard. Spontaneous platelet aggregation and the aggregation responses to ADP, epinephrine, collagen, ristocetin and thrombin were measured turbidimetrically in an aggregometer. Dose-response and dose-rate curves were constructed for ADP- and epinephrine-induced aggregation. The maximum aggregation response (EDmax) and rate (EDRmax), and the estimated dose of agonist to induce 50% of the maximum response (ED50) and rate (EDR50) were calculated from these curves. The inhibition of ADP-induced aggregation with PGI2 was expressed as per cent inhibition. The release of ATP and TxA2, from platelets aggregated with collagen was measured. No spontaneous aggregation occurred with either anticoagulant. The ED50 and the EDR50 for heparinized platelets were significantly lower for ADP induced aggregation (0.8 +/- 0.3 microM vs 2.1 +/- 1.0 microM [p = 0.001] and 0.4 +/- 0.1 microM vs 0.8 +/- 0.3 microM [p = 0.003]). The EDRmax with ADP was significantly higher (p = 0.004) for heparinized platelets (64.6 +/- 17.0 units/ml vs 50.4 +/- 7.6 units/ml). The heparinized platelets aggregated slightly, but significantly, less in response to ristocetin than the citrated platelets. The response of washed heparinized and citrated platelets to thrombin was not significantly different. The per cent inhibition of ADP aggregation with PGI2, was significantly lower with heparinized platelets. The release of TxA2 and ATP was similar for both anticoagulants. These results indicate that LMW heparin is a satisfactory anticoagulant for platelet aggregation tests.
我们评估了低分子量（LMW）肝素作为抗凝剂用于11名正常志愿者体外血小板功能测试的适用性。以枸橼酸化血小板的结果作为标准。在血小板聚集仪中通过比浊法测量自发性血小板聚集以及对ADP、肾上腺素、胶原、瑞斯托菌素和凝血酶的聚集反应。构建了ADP和肾上腺素诱导聚集的剂量-反应曲线和剂量-速率曲线。从这些曲线计算出最大聚集反应（EDmax）和速率（EDRmax），以及诱导50%最大反应的激动剂估计剂量（ED50）和速率（EDR50）。用前列环素（PGI2）对ADP诱导聚集的抑制作用以抑制百分比表示。测量了与胶原聚集的血小板中ATP和血栓素A2（TxA2）的释放。两种抗凝剂均未出现自发性聚集。对于ADP诱导的聚集，肝素化血小板的ED50和EDR50显著更低（0.8±0.3微摩尔/升对2.1±1.0微摩尔/升[p = 0.001]，0.4±0.1微摩尔/升对0.8±0.3微摩尔/升[p = 0.003]）。对于肝素化血小板，ADP诱导的EDRmax显著更高（p = 0.004）（64.6±17.0单位/毫升对50.4±7.6单位/毫升）。与枸橼酸化血小板相比，肝素化血小板对瑞斯托菌素的反应轻微但显著降低。洗涤后的肝素化血小板和枸橼酸化血小板对凝血酶的反应无显著差异。肝素化血小板用PGI2对ADP聚集的抑制百分比显著更低。两种抗凝剂的TxA2和ATP释放相似。这些结果表明，低分子量肝素是血小板聚集试验中一种令人满意的抗凝剂。
