Martinez-Sales Vicenta, Vila Virtudes, Réganon Edelmiro, Oms Javier Garcia, Aznar Justo
Centro de Investigación, La Fe University Hospital, Valencia, Spain.
Haematologica. 2003 Jun;88(6):694-9.
Unfractionated heparin and low molecular weight heparins exert their anticoagulant effect by mobilizing tissue factor pathway inhibitor (TFPI) from the vascular endothelium into the blood circulation. We compared the influence of unfractionated heparin and enoxaparin on the anticoagulant function of cultured human endothelial cells.
Monolayers of human umbilical vein endothelial cells were treated with 10 U/mL unfractionated heparin or enoxaparin for different periods of time (30min-48h). Endothelial cell procoagulant activity was determined in the cell lysates by a chromogenic assay. Endothelial cell tissue factor (TF) and released TFPI and von Willebrand factor (vWF) was determined.
In short periods of incubation (30min-2h), both heparins reduced endothelial cell procoagulant activity, the inhibition produced by unfractionated heparin being greater than that induced by enoxaparin (p<0.05). However, no variations were observed in TFPI and vWF release. With long periods of incubation (24-48h), both unfractionated heparin and enoxaparin significantly increased TFPI release (control vs. unfractionated heparin, p<0.05-0.001; control vs. enoxaparin, p<0.01-0.001) and also reduced the release of vWF in the culture medium, though no variations in endothelial cell procoagulant activity or TF content were observed.
Our findings show that unfractionated heparin and enoxaparin exert different kinds of effects on endothelial cells. With short incubation periods, procoagulant endothelial cell capacity was reduced to a greater extent by unfractionated heparin, while after longer periods of incubation enoxapain increased the anticoagulant activity of the endothelial cells to a greater degree than did unfractionated heparin.
普通肝素和低分子量肝素通过将组织因子途径抑制物（TFPI）从血管内皮细胞动员到血液循环中来发挥抗凝作用。我们比较了普通肝素和依诺肝素对培养的人内皮细胞抗凝功能的影响。
用人脐静脉内皮细胞单层分别用10 U/mL普通肝素或依诺肝素处理不同时间（30分钟至48小时）。通过显色测定法测定细胞裂解物中的内皮细胞促凝活性。测定内皮细胞组织因子（TF）、释放的TFPI和血管性血友病因子（vWF）。
在短时间孵育（30分钟至2小时）时，两种肝素均降低了内皮细胞促凝活性，普通肝素产生的抑制作用大于依诺肝素（p<0.05）。然而，未观察到TFPI和vWF释放的变化。在长时间孵育（24至48小时）时，普通肝素和依诺肝素均显著增加TFPI释放（对照组与普通肝素组，p<0.05至0.001；对照组与依诺肝素组，p<0.01至0.001），并且还降低了培养基中vWF的释放，尽管未观察到内皮细胞促凝活性或TF含量的变化。
我们的研究结果表明，普通肝素和依诺肝素对内皮细胞发挥不同类型的作用。在短孵育期，普通肝素对内皮细胞促凝能力的降低程度更大，而在较长孵育期后，依诺肝素比普通肝素更能增强内皮细胞的抗凝活性。
