In Vivo Studies on the Inhibition of Coagulation by Fractionated Heparin and by a Heparin Analogue I. Effects of Heparin Fractions

Summary

High and low molecular weight heparin fractions obtained by gel filtration chromatography of sodium mucosal heparin were injected subcutaneously into six healthy volunteers and compared with the unfractionated substance in a cross-over trial. Equal doses of 5,000 U were administered twice daily over a period of three days and heparin activity was repeatedly controlled before and 2, 4, 8 hrs after injection by means of the APTT, the anti-Xa clotting test and a chromogenic substrate assay. In addition, the in vivo effect of subcutaneously administered fractionated heparin on platelet function was examined on three of the volunteers. The results show that s.c. injections of the low molecular weight fraction induced markedly higher anti-Xa activity than injections of the other preparations. At the same time, APTT results did not significantly differ. Unfractionated heparin and the high molecular weight fraction enhanced ADP-induced platelet aggregation and collagen-mediated MDA production, while the low molecular weight fraction hardly affected these assays, but potently inhibited thrombin-induced MDA production. All heparin preparations stimulated the release of platelet Factor 4 in plasma. During the three-day treatment periods, no side-effects and no significant changes in the response to heparin injections were detected.

Keywords

Heparin fractionation - Anti-Xa activity - Platelet function - Thrombosis prophylaxis

• References

• 1 Johnson EA, Kirkwood TB L, Stirling Y, Perez-Requejo JL, Ingram GI C, Bangham DR, Brozovic M. Four heparin preparations: anti-Xa potentiating effect of heparin after subcutaneous injection. Thromb Haemostas 1976; 35: 586-591
• 2 Lane DA, Mac Gregor IR, van Ross M, Cella G, Kakkar VV. Molecular weight dependence of the anticoagulant properties of heparin: intravenous and sub-cutaneous administration of fractionated heparins to man. Thromb Res 1979; 16: 651-662
• 3 Thomas DP, Barrowcliffe TW, Johnson EA. The influence of tissue source, salt and molecular weight on heparin activity. In Verstraete M, Machin SJ. (eds.) Clinical Usage of Heparin: Present and Future Trends Scand J Haematol 1980; Vol 25 Suppl (Suppl. 36) 40-49
• 4 Barrowcliffe TW, Johnson EA, Eggleton CA, Kemball-Cook G, Thomas DP. Anticoagulant activities of high and low molecular weight heparin fractions. Br J Haematol 1979; 41: 573-583
• 5 Holmer E, Lindahl U, Bäckström G, Thunberg L, Sandberg H, Söderström G, Andersson LO. Anticoagulant activities and effects on platelets of a heparin fragment with high affinity for antithrombin. Thromb Res 1980; 18: 861-869
• 6 Yin ET, Wessler S, Butler J. Plasma heparin: A unique, practical, submicrogram sensitive assay. J Lab Clin Med 1973; 81: 298-310
• 7 Taberner DA, Norman C, Poller L, Burslem RW, Jones JB. The value of standardized partial thromboplastin time in detecting heparin during low-dose prophylaxis. Br J Haematol 1979; 43: 317-322
• 8 Teien AN, Lie M, Abildgaard U. Assay of heparin in plasma using a chromogenic substrate. Thromb Res 1976; 8: 413-416
• 9 Larsen ML, 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
• 10 Teien AN, Lie M. Evaluation of an amidolytic heparin assay method. Increasing sensitivity by adding purified AT III Thromb Res 1977; 10: 399-410
• 11 Ødegard OR. Evaluation of an amidolytic heparin cofactor assay method. Thromb Res 1975; 7: 351-360
• 12 Clauss A. Gerinnungsphysiologische Schnellmethode zur Bestimmung von Fibrinogen. Acta Haematol 1957; 17: 237-246
• 13 Born GV R, Cross MJ. The aggregation of human blood platelets. J Physiol 1963; 168: 178-195
• 14 McMillan R, MacIntyre E, Cordon JL. Simple sensitive fluorometric assay for malondialdehyde production by platelets. Thromb Res 1977; 11: 425-428
• 15 Stuart M, Murphy S, Oski EA. A simple non-radioisotope technic for the determination of platelet lifespan. New Engl J Med 1975; 292: 1310-1313
• 16 Drummond AM, Gordon JL. Rapid, sensitive microassay for platelets 5 HT. Thrombos Diathes Haemorrh 1974; 31: 366-367
• 17 Zucker MB. Biological aspects of heparin action. Heparin and platelet function Fed Proc 1977; 36: 47-49
• 18 Salzman EW, Rosenberg RD, Smith MH, Lindon JN, Favreau L. Effect of heparin and heparin fractions on platelet aggregation. J Clin Invest 1980; 65: 64-73
• 19 Harada K, Zucker MB. Simultaneous developments of platelet factor 4 activity and release of ¹⁴C-serotonin. Thrombos Diathes Haemorrh 1971; 25: 41-46
• 20 Dawes J, Smith RC, Pepper DS. The release, distribution and clearance of human β-thromboglobin and platelet factor 4. Thromb Res 1978; 12: 851-861
• 21 Busch C, Dawes J, Pepper DS, Wasteson A. Binding of platelet factor 4 to cultured human umbilical vein endothelial cells. Thromb Res 1980; 19: 129-137
• 22 Eika C. Inhibition of thrombin induced aggregation of human platelets by heparin. Scand J Haematol 1971; 8: 216-222
• 23 Michalski R, Lane DA, Kakkar VV. Comparison of heparin and a semisynthetic heparin analogueA 73025. II. Some effects on platelet function Br J Haematol 1977; 37: 247-255