Cosmi Benilde, Cini Michela, Legnani Cristina, Pancani Claudia, Calanni Fiorella, Coccheri Sergio
Divisione di Angiologia e Malattie della Coagulazione, Policlinico S.Orsola-Malpighi, Università degli Studi di Bologna, Bologna, Italy.
Thromb Res. 2003 Mar 15;109(5-6):333-9. doi: 10.1016/s0049-3848(03)00246-9.
The aim of the study was to evaluate the mechanism of the anticoagulant action of sulodexide, a mixture of glycosaminoglycans (GAGs) composed of dermatan sulfate (DS) and fast moving heparin (FMH), in vitro.
Thrombin clotting time (TCT) was measured in human platelet poor plasma (PPP). A chromogenic substrate assay was used to determine the pseudo-first order constant kinetic of thrombin inhibition (k'=k(obs)/min) either in defibrinated PPP or antithrombin (AT) or heparin cofactor II (HCII) depleted defibrinated PPP in the absence and presence of sulodexide or its components, alone and in combination. The interaction between DS and FMH was analysed by both the algebraic fractional and isobole graphical methods.
Sulodexide, DS and FMH produced a dose-dependent prolongation of TCT with unclottable TCT at sulodexide above 4 microg/ml and at DS or FMH above 5 microg/ml. Sulodexide and its components alone and in combination produced a dose-dependent linear increase in the rate of thrombin inhibition in defibrinated PPP. The algebraic fractional and the isobole graphical methods indicated an additive effect between DS and FMH. In AT depleted PPP, the dose-dependent increase in k' produced by sulodexide was significantly lower than in PPP, while the dose-dependent increase in k' produced by DS was similar to the increase produced in PPP. In HCII depleted PPP, the dose-dependent increase in k' produced by sulodexide was significantly lower than in PPP, while the dose-dependent increase in k' produced by FMH was similar to the increase produced in PPP.
Thrombin inhibition produced by sulodexide is due to the additive effect of its components, namely, HCII catalysis by DS and AT catalysis by FMH.
本研究的目的是在体外评估舒洛地特（一种由硫酸皮肤素（DS）和快速移动肝素（FMH）组成的糖胺聚糖（GAG）混合物）的抗凝作用机制。
在人乏血小板血浆（PPP）中测量凝血酶凝结时间（TCT）。采用发色底物测定法，在不存在和存在舒洛地特或其组分单独及组合的情况下，测定去纤维蛋白PPP或抗凝血酶（AT）或肝素辅因子II（HCII）缺乏的去纤维蛋白PPP中凝血酶抑制的伪一级常数动力学（k' = k(obs)/min）。通过代数分数法和等效线图法分析DS和FMH之间的相互作用。
舒洛地特、DS和FMH使TCT呈剂量依赖性延长，舒洛地特浓度高于4μg/ml以及DS或FMH浓度高于5μg/ml时TCT无法凝结。舒洛地特及其组分单独及组合使用时，去纤维蛋白PPP中凝血酶抑制率呈剂量依赖性线性增加。代数分数法和等效线图法表明DS和FMH之间存在相加作用。在AT缺乏的PPP中，舒洛地特产生的k'剂量依赖性增加显著低于PPP中的增加，而DS产生的k'剂量依赖性增加与PPP中的增加相似。在HCII缺乏的PPP中，舒洛地特产生的k'剂量依赖性增加显著低于PPP中的增加，而FMH产生的k'剂量依赖性增加与PPP中的增加相似。
舒洛地特产生的凝血酶抑制作用归因于其组分的相加作用, 即DS对HCII的催化作用和FMH对AT的催化作用。
