Fibrin Network Structure: Modification by Platelets

Summary

Platelets play a fundamental role in haemostasis and thrombosis. They are known to undergo characteristic changes including release of subcellular material during clotting. The effect of subcellular platelet material on fibrin network structure, however, has not previously been investigated. Using opacity ratio, syneresis, permeation and electron microscopy it was found that subcellular platelet material extracted into NaCl is able to influence fibrin network structure of clots made from purified fibrinogen as well as platelet-poor plasma. Such clots had higher opacity ratio, reduced syneresis and lower permeability than control clots. Further, the responsible platelet material is heat labile and is released from the platelets during their aggregation with several common aggregating agents. Morphometric analysis of transmission electron micrographs has shown that fibrin fibres in plasma clots made in the presence of platelet subcellular material are thinner than those in control clots. In addition, plasma clots made in the presence of platelet extract had a higher resistance to fibrinolytic digestion than control clots. Thus, platelets play a hitherto undescribed role in regulating fibrin network structure.

Keywords

Platelets - Fibrin network structure - Fibrinolysis

• References

• 1 Holmsen H, Salganicoff L, Fukami MH. Platelet behaviour and biochemistry. In: Haemostasis: Biochemistry, physiology and pathology. Ogston D, Bennett B. (Eds), pp 239-319 John Wiley and Sons; London: 1977
• 2 Ferguson IA, Dhall TZ, Shah GA, Dhall DP. The effect of ionic composition on fibrin network structure. In: Progress in microcirculation research. Garlick D. (Ed), pp 545-552 Committee in Postgraduate Medical Education. The University of New South Wales; Sydney: 1981
• 3 Schuman MA, Levine SP. Thrombin generation and secretion of platelet factor 4 during blood clotting. J Clin Invest 1978; 61: 1102-1106
• 4 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
• 5 Ardlie NG, Han P. Enzymatic basis for platelet aggregation and release: the significance of the “platelet atmosphere” and the relationship between platelet function and blood coagulation. Br J Haematol 1974; 26: 331-356
• 6 Muzaffar TZ, Stalker AL, Bryce WA J, Dhall DP. Structural alterations in fibrin clots with dextran. Thrombos Diathes Haemorrh 1972; 28: 257-267
• 7 Dhall TZ, Bryce WA J, Dhall DP. Effects of dextran on the molecular structure and tensile behaviour of human fibrin. Thromb Haemostas 1976; 35: 737-745
• 8 Carr Jr ME, Shen LL, Hermans J. Mass-length ratio of fibrin fibres from gel permeation and light scattering. Biopolymers 1977; 16: 1-15
• 9 Stewart GJ, Niewiarowski S. Nonenzymatic polymerization of fibrinogen by protamine sulphate. An electron microscope study. Biochim Biophys Acta 1969; 194: 462-469
• 10 Glover D, Warner ED. A multiparameter coagulation and fibrinolysis screening test using the platelet aggregometer. Am J Clin Pathol 1975; 63: 74-80
• 11 Thomson JM. A practical guide to blood coagulation and haemostasis. pp 169-170 Churchill, London: 1970
• 12 Ferry JD, Morrison PR. Preparation and properties of serum and plasma proteins. VIII. The conversion of human fibrinogen to fibrin under various conditions. J Am Chem Soc 1947; 69: 388-400
• 13 Wester J, Sixma JJ, Geuze JJ, Heijnen HF G. Morphology of the haemostatic plug in human skin wounds. Transformation of the plug. Lab Invest 1979; 41: 182-192
• 14 Ottolander GJ H den, Leijnse B, Cremer-Elfrink HM J. Plasmatic and thrombocytic anti-plasmins and anti-activators. II. Thrombos Diathes HaemorTh 1969; 21: 26-34