Comparative Inhibition of Extrinsic and Intrinsic Thrombin Generation by Standard Heparin, a Low Molecular Weight Heparin and the Synthetic ATIII-Binding Pentasaccharide

Summary

The inhibiting effect of standard heparin, CY216 and the ATIII-binding synthetic pentasaccharide on extrinsic and intrinsic thrombin generation were quantified by evaluating the decrease of the total amount of active thrombin appearing in plasma after triggering coagulation.

Heparin as well as CY 216 produced the same quantitative inhibition of extrinsic and intrinsic TGs whereas pentasaccharide inhibited more efficiently extrinsic TG.

This pattern of inhibition was further confirmed on pure extrinsic or intrinsic coagulation respectively in factor IX- and factor VII-depleted plasmas.

Furthermore, selective suppression of the anti-thrombin activity of CY 216 by limited amounts of PF4 affected the intrinsic TG inhibition more markedly than the extrinsic one.

It was concluded that anticoagulant activity produced mainly through thrombin scavenging leads to similar quantitative impairment of extrinsic and intrinsic coagulation, while selective ATIII-mediated factor Xa inhibition results in a more marked effect against the extrinsic system.

• References

• 1 Béguin S, Lindhout T, Hemker HC. The mode of action of heparin in plasma. Thromb Haemostas 1988; 60: 457-462
• 2 Ofosu FA, Blajchman MA, Modi GJ, Smith IM, Buchanan MR, Hirsh J. The importance of thrombin inhibition for the expression of the anticoagulant activities of heparin, dermatan sulphate, low molecular weight heparin and pentosan polysulphate. Br J Haematol 1985; 60: 695-704
• 3 Béguin S, Wielders S, Lormeau JC, Hemker HC. The mode of action of CY216 and CY222 in plasma. Thromb Haemostas 1992; 67: 33-41
• 4 Ofosu FA, Sie P, Modi GJ, Fernandez F, Buchanan MR, Blajchman MA, Boneu B, Hirsh J. The inhibition of thrombin-dependent positive-feedback reactions is critical to the expression of the anticoagulant effect of heparin. Biochem J 1987; 243: 579-588
• 5 Ofosu FA, Hirsh J, Esmon CT, Modi GJ, Smith LM, Anvari N, Buchanan MR, Fenton JW, Blajchman MA. Unfractionated heparin inhibits thrombin-catalysed amplification reactions of coagulation more efficiently than those catalysed by factor Xa. Biochem J 1989; 257: 143-150
• 6 Pieters J, Lindhout T. The limited importance of factor Xa inhibition to the anticoagulant property of heparin in thromboplastin-activated plasma. Blood 1988; 72: 2048-2052
• 7 Choay J, Petitou M, Lormeau JC, Sïnay P, Casu B, Gatti G. Structure activity relationship in heparin: A synthetic pentasaccharide with high affinity for antithrombin III and eliciting high anti-factor Xa activity. Biochem Biophys Res Commun 1983; 116: 492-499
• 8 Béguin S, Choay J, Hemker HC. The action of a synthetic pentasaccharide on thrombin generation in whole plasma. Thromb Haemostas 1989; 61: 379-401
• 9 Hemker HC. The mode of action of heparin in plasma. In: Thrombosis and Haemostasis. Verstraete M, Vermylen J, Lijnen HR, Arnout J. (eds). International Society on Thrombosis and Haemostasis and Leuven University Press; Leuven: 1987: 17-36
• 10 Hemker HC, Willems GM, Béguin S. A computer assisted method to obtain the prothrombin activation velocity in whole plasma independent of thrombin decay processes. Thromb Haemostas 1986; 56: 9-17
• 11 Schoen P, Lindhout T, Hemker HC. Low molecular weight heparin catalyzed inactivation of factor Xa and thrombin by antithrombin III - Effect of platelet factor 4. Thromb Haemostas 1991; 66: 435-441
• 12 Lie Larsen M, Abildgaard U, Teien AN, Gjesdal K. Assay of plasma heparin using thrombin and the chromogenic substrate H-D-Phe-Pip-Arg-pNa (S-2238). Thromb Res 1978; 13: 285-288
• 13 Teien AN, Lie M. Evaluation of an amidolytic heparin assay method: increased sensitivity by adding purified antithrombin III. Thromb Res 1977; 10: 399-410
• 14 Odegard OR, Lie M, Abildgaard U. Heparin cofactor activity measured with an amidolytic method. Thromb Res 1975; 6: 287-294
• 15 Fair DS, Egdington TS. Heterogeneity of hereditary and acquired factor X deficiencies by combined immunochemical and functional analyses. Br J Haematol 1985; 59: 235-248
• 16 Alagille D, Hartman L, Fauvert R. Etude analytique du temps de Quick au cours de l’insuffisance hépatique, par les dosages différentiels de la prothrombine, de la proconvertine et de la proaccélérine. Sem Hôp Paris 1953; 66: 3375-3386
• 17 Soulier JP, Larrieu MJ. yEtude analytique des temps de Quick allongés.Dosage de prothrombine, de proconvertine et de proaccélérine. Sang 1952; 23: 549-559
• 18 Caen J, Larrieu MJ. Samama ML’hémostase. Méthode d’exploration et diagnostic pratique. Paris, L’Expansion Scientifique 1975; 153-156
• 19 Zacharski LR, Rosenstein R. Standardization of the one-stage assay for factor VIII (antihaemophilic factor). Am J Clin Pathol 1978; 70: 280-286
• 20 Nossel HL, Niemetz J, Schulze WG. The measurement of factor XI (plasma thromboplastin antecedent).Diagnostic and therapy of the congenital deficiency state. Br J Haematol 1966; 12: 133-144
• 21 Griffin JH, Cochrane MJ. Human factor XII (Hageman factor). In: Methods in Enzymology. Lorand L. (ed). New York: Academic Press; 1976. 45 56-65
• 22 Béguin S, Dol F, Hemker HC. Factor IXa inhibition contributes to the heparin effect. Thromb Haemostas 1991; 66: 306-309
• 23 Hemker HC, Choay J, Béguin S. Free factor Xa is on the main pathway of thrombin generation in clotting plasma. Biochem Biophys Acta 1989; 992: 409-411
• 24 Masys DR, Bajaj SP, Rapaport SI. Activation of human factor VII by activated factors IX and X. Blood 1982; 60: 1143-1150