DX-9065a, an Orally Active, Specific Inhibitor of Factor Xa, Inhibits Thrombosis without Affecting Bleeding Time in Rats

Summary

We evaluated the antithrombotic effects of DX-9065a, a specific factor Xa inhibitor, using tissue thromboplastin-induced DIC (TP-DIC) and the arterio-venous shunt (AV shunt) in rats. Intravenous TP injection reduced the platelet counts and fibrinogen concentrations in blood. In the TP-DIC model, an intravenous dose of DX-9065a 0.23 mg/kg 1 min before TP injection suppressed the consumption of platelets and fibrinogen to 57% and 66%, respectively, and the production of FDP almost completely. In the AV shunt model, DX-9065a inhibited thrombus formation to 51% on intravenous administration of 0.23 mg/kg and to 60% when given orally at 23.3 mg/kg. Intravenous administration of 2.33 mg/kg of DX-9065a did not affect the bleeding time. These results suggest that Xa inhibition may be an appropriate approach for suppressing thrombosis without impairing haemostasis.

• References

• 1 Andersson LO, Barrowcliffe TW, Holmer E, Johnson EA, Sims GE C. Anticoagulant properties of heparin fractionated by affinity chromatography on matrix-bound antithrombin III and by gel filtration. Thromb Res 1976; 9: 575-583
• 2 Stenflo J, Suttie JW. Vitamin K-dependent formation ofγ-carboxyglulamic acid. Ann Rev Biochem 1977; 46: 157-172
• 3 Weitz JI, Hudoba M, Massel D, Maraganore J, Hirsh J. Clot bound thrombin is protected from inhibition by heparin-antithrombin III but is susceptible to inactivation by antithrombin Ill-independent inhibitors. J Clin Invest 1990; 86: 385-391
• 4 Casu B, Oreste P, Torri G, Zoppetti G, Choay J, Lormeau JC, Petitou M, Sinay P. The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin Ill-binding sequence: chemical and 13C nuclearmagnetic-resonance studies. Biochem J 1981; 197: 599-609
• 5 Choay J, Lormeau JC, Petitou M, Sinay P, Eareed J. Structural studies on a biologically active hexasaccharidc obtained from heparin. Ann NY Acad Sci 1981; 370: 644-649
• 6 Choay J, Petitou M, Lormeau JC, Sinay P, Casu B, Gaui G. Structure- activity relationship in heparin: a synthetic pentasaccharide with high affinity for thrombin III and eliciting high anti-factor Xa activity. Biochem Biophys ResCommun 1983; 116: 492-499
• 7 Furie B, Lurie BC. Molecular Basis of Vitamin K-Depeiulenl γ-Carboxyla lion. Blood 1990; 75: 1753-1762
• 8 Okumoto S, Hijikata A, Kikumoto R, Tonomura S, Hara H, Ninomiya K, Maruyama A, Sugano M, Tamao Y. Potent inhibition of thrombin by the newly synthesized arginine derivative No. 805.. The importance of stereo structure of its hydrophobic carboxamide portion Biochem Biophys Res Commun 1981; 101: 440-446
• 9 Kelly AB, Maraganore JM, Bourdon P, Hanson SR, Harker LA. Antithrombotic effects of synthetic peptides targeting various functional domains of thrombin. Proc Natl Acad Sci 1992; 89: 6040-6044
• 10 Bagdy D, Barábas É, Szabó G, Bajusz S, Szèll E. In vivo anticoagulant and antiplatelet effect of D-Phc-Pro-Arg-H and D-MePhe-Pro-Arg-H. Thromb Hacmost 1992; 67: 357-365
• 11 Nagahara T, Yokoyama Y, Inamura K, Katakura S, Komoriya S, Yamaguchi H, Hara T, Iwamoto M. Dibasic (Amidino-ary1)-propanoic acid derivative as novel blood coagulation factor Xa inhibitors. J Med Chem 1994; 37: 1200-1207
• 12 Hara T, Yokoyama A, Ishihara H, Yokoyama Y, Nagahara T, Iwamoto M. DX-9065a, a new synthetic, potent anticoagulant and selective inhibitor for factor Xa. Thromb Haemost 1994; 71: 314-319
• 13 Lowry OH, Rosebrough NJ, Farr AL, Randall RJ. Protein measurement with the Folin phenol reagent. J Biol Chem 1951; 193: 265-275
• 14 Ratnoff OD, Menzie C. A new method for the determination of fibrinogen in small samples of plasma. J Lab Clin Med 1951; 37: 316-320
• 15 El di S, radi K V. Optimization of conditions for the catalytic effect of the factor IXa-factor VIII complex: Probable role of the complex in the amplification of blood coagulation. Thromb Res 1979; 15: 617-629
• 16 Agnelli G, Renga C, Weitz JI, Nenci GG, Hirsh J. Sustained antithrombotic activity of hirudin after its plasma clearance: Comparison with heparin. Blood 1992; 80: 960-965
• 17 Gruber A, Harker LA, Hanson SR, Kelly AB, Griffin JH. Antithrombotic effects of combining activated protein C and urokinase in nonhuman primates. Circulation 1991; 84: 2454-2462
• 18 Neeper MP, Waxman L, Smith DE, Schulman CA, Sardana M, Ellis RW, Schaffer LW, Siegel PK S, Vlasuk GP. Charcterization of recombinant tick anticoagulant peptide: A highly selective inhibitor of blood coagulation factor Xa. J Biol Chem 1990; 265: 17746-17752