The Mode of Action of Heparin in Plasma^[*]

Summary

The influence of heparin on prothrombin conversion in plasma was estimated by measuring prothrombin disappearance with the aid of staphylocoagulase or by calculation from the thrombin generation curve, compensating for simultaneous thrombin inactivation by plasma protease inhibitors. In thromboplastin-activated plasma the effect of heparin on prothrombinase (factor X_a-factor V_a-phospholipid) is negligible compared to that on thrombin probably because both the extrinsic factor X activating complex and phospholipid bound factor X_a are insensitive to AT III-heparin action. In contact-activated plasma prothrombinase generation is inhibited by heparin, because heparin lowers the ambient concentrations of thrombin so that the feedback activation of factor VIII by thrombin is diminished. Consequently, the delayed factor X_a generation causes a lag phase in prothrombinase generation. We conclude that heparin in plasma acts by its thrombin scavenging properties. No direct action on prothrombinase or on the factor X activating enzyme needs to be assumed if one takes into account the effect of thrombin depletion on thrombin-mediated feedback reactions

Keywords

Prothrombin activation - Heparin - Plasma protease inhibitors

Part of this work has been presented at the XIth International Society of Thrombosis and Haemostasis Congress, Brussels, 1987

• References

• 1 Griffith MJ. Inhibitors: Antithrombin III and heparin. In: Blood Coagulation Zwaal RF A, Hemker HC. (eds) Elsevier, Amsterdam: 1986: 259-283
• 2 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
• 1 Jesty J. The kinetics of inhibition of alpha-thrombin in human plasma. J Biol Chcm 1986; 261: 10313-10318
• 4 Jesty J. Analysis of the generation and inhibition ot activated coagulation factor X in pure systems and in human plasma. J Biol Chem 1986; 261: 8695-8702
• 5 Nemerson Y, Furie B. Zymogens and cofactors of blood coagulation. CRC Crit Rev Biochem 1980; 9: 45-85
• 6 Marciniak E. Factor X_a inactivation by antithrombin III: evidence for biological stabilization of factor X_a by factor V-phospholipid complex. Br J Haematol 1973; 24: 391-400
• 7 Walker FJ, Esmon CT. The effects of phospholipid and factor Va on the inhibition of factor X_a by antithrombin III. Biochem Biophys Res Commun 1979 90. 641-647
• 8 Lindhout T, Baruch D, Schoen P, Franssen J, Hemker HC. Thrombin generation and inactivation in the presence of antithrombin III and heparin. Biochemistry 1986; 25: 5962-5969
• 9 Barrowcliffe TW, Havercroft SJ, Kemball-Cook G, Lindhal U. The effects of Ca²⁺, phospholipid and Factor V on the anti-(factor X_a) activity of heparin and its high affinity oligosaccharides. Biochem J 1987; 243: 31-37
• 10 Carter CJ, Kelton JG, Hirsh J, Cerskus A, Santes AV, Gent M. The relationship between the hemorrhagic and antithrombotic properties of low molecular weight heparin in rabbits. Blood 1982; 59: 1239-1245
• 11 Thomas DP. Current status of low molecular weight heparin. Thromb Haemostas 1986; 56: 241-242
• 12 Buchanan MR, Boneu B, Ofosu F, Hirsh J. The relative importance of thrombin inhibition and factor Xa inhibition to antithrombotic of effects heparin. Blood 1985; 65: 198-201
• 13 Teitel JM, Bauer KA, Lau HK, Rosenberg RD. Studies of the prothrombin activation pathway utilizing radioimmunoassays for the F₂/F₁₊₂ fragment and thrombin-antithrombin complex. Blood 1982; 59: 1086-1097
• 14 Ofosu FA, Modi GJ, Hirsch J, Buchanan MR, Blajchman MA. Mechanism for inhibition of the generation of thrombin activity by sulfated polysaccharides. Ann N Y Acad Sci 1986; 485: 41-55
• 15 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 anti-coagulant effect of heparin. Biochem J 1987; 243: 579-588
• 16 Hemker HC. The mode of action of heparin in plasma. In: Thrombosis and Haemostasis 1987 Verstraete M, Lijnen HR, Arnout J. (eds) International Society on Thrombosis and Haemostasis. Leuven University Press, Leuven: 1987: 17-36
• 17 Rosing J, Tans G, Govers-Riemslag JW P, Zwaal RF A, Hemker HC. The role of phospholipids and factor V_a in the prothrombinase complex. J Biol Chem 1980; 255: 274-283
• 18 van Dam-Mieras MC E, Muller AD, van Dieijen G, Hemker HC. In: Methods of Enzymatic Analysis Enzymes 3: Peptidases, Proteinases and Their Inhibitors. Bergmeyer HU. (ed) Verlag Chemie, Weinheim: 1984: 352-354
• 19 Owen PA, Aas K. The control of dicoumarol therapy and the quantitative determination of prothrombin and proconvertin. Scand J Clin Lab Invest 1951; 3: 201-218
• 20 Hendrix H, Lindhout T, Mertens K, Engels W, Hemker HC. Activation of human prothrombin by stoichiometric levels of staphylocoagulase. J Biol Chem 1983; 258: 3637-3644
• 21 Pletcher CH, Nelsestuen GL. The rate determining step of the heparin-catalyzed antithrombin-thrombin reaction is independent of thrombin. J Biol Chem 1982; 257: 5342-5345
• 22 Lindhout T, Govers-Riemslag JW P, van de Waart P, Hemker HC, Rosing J. Factor V_a factor X_a interaction. Effects of phospholipid vesieles of varying composition. Biochemistry 1982 21. 5494-5502
• 23 Vehar GA, Davie EW. Preparation and properties of bovine factor VIII. Biochemistry 1980; 19: 401-410
• 24 van Dieijen G, van Rijn JL M L, Govers-Riemslag JW P, Hemker HC, Rosing J. Assembly of the intrinsic factor X activating complex; interactions between factor IX_a, factor VIII_a and phospholipid. Thromb Haemostas 1985 53. 396-400
• 25 Fujikawa K, Thompson AR, Legaz ME, Meyer RG, Davie EW. Isolation and characterization of bovine factor IX (Christmas Factor). Biochemistry 1980; 12: 4938-4945
• 26 Fujikawa K, Legaz ME, Kato H, Davie EW. The mechanism of activation of bovine factor IX (Christmas factor) by bovine factor XT_a (activated plasma thromboplastin antecedent). Biochemistry 1974; 13: 4508-4516
• 27 Beck JV, Arnold KJ. Parameter Estimation in Engineering and Science. J Wiley and Sons, New York 1977
• 28 Lijnen HR, van Hoef B, Collen D. Interaction of heparin with histidine-rich glycoprotein and with antithrombin III. Thromb Haemostas 1983; 50: 560-562
• 29 Preissner KT, Wassmuth R, Miiller-Berghaus G. Physicochemical characterization of human S-protein and its function in the blood coagulation system. Biochem J 1985; 231: 349-355
• 30 Podack ER, Dahlbäck B, Griffin JH. Interaction of S-protein of complement with thrombin and antithrombin III during coagulation. J Biol Chem 1986; 261: 7387-7392
• 31 Schoen P, Lindhout T. The in situ inhibition of prothrombinase-formed human ゑ-thrombin and meizothrombin(des F1) by antithrombin III and heparin. J Biol Chem 1987; 262: 11268-11274
• 32 McNeely TB, Griffin MJ. The anticoagulant mechanism of action of heparin in contact-activated plasma Inhihition of factor X activation. Blood 1985; 60: 1226-1231
• 33 Scott C, Schapira M, Colman RW. Effect of heparin on the activation rate of factor XI_a by antithrombin III. Blood 1982; 60: 940-948
• 34 Ofosu FA, Blajchman MA, Modi GJ, Smith LM, 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