An Investigation of the Possible Role of Platelet Fibrinogen in Thrombi Formation^[*]

Summary

We have prepared solid clots that could be fixed, sectioned and stained and studied histologically from a high concentration of washed platelets in buffered saline. Plasma fibrinogen is not required for a clot with structure to form. The possibility of packed platelets composing the head of mixed thrombi is evident if a small amount of thrombin can be formed and the microscopic appearance of such a structure documented. No clot retraction of platelet fibrin took place. The platelet-plasma clots prepared as controls in this study lysed very readily when streptokinase was incorporated into the clot while it was not possible to lyse the washed platelet clots in the conditions of the experiment. Neither clot could be lysed with fibrinolysin.

• References

• 1 Poole J. C. A study of artificial thrombi produced by a modification of Chandler’s method. Quart. J. exp. Physiol. 44: 377 1959;
• 2 Brambel E. C. In vitro platelet aggregation in relation to metal ions, macromolecules and surfaces. In: Johnson S. A, Monto R. W, Rebuck J. W, Horn R. C. (ed): The blood Platelets. X. int. Symp. Henry Ford Hospital, Detroit. Little, Brown &c Co; Boston: 1961
• 3 O’Brien J. R. The adhesiveness of native platelets and its prevention. J. clin. Path. 14: 140 1961;
• 4 Ashwin J. G. The effect of drugs on experimental thrombogenesis. In Anticoagulants and Fibrinolysins. Ed. by MacMillan R. L, Mustard J. F. Int. Symp. Toronto. Mac Millan: 1961
• 5 Jackson D. P, Schmid N. J, Conley C. L. Action of thrombin on platelets. Thrombos. Diathes. haemorrh. (In press.).
• 6 Johnson S. A, Monto R. W, Caldwell M. J. Relation of platelet factor 1 and platelet fibrinogen to plasma. J. appl. Physiol. 13: 406 1958;
• 7 Ware A. G, Fahey J. L, Seegers W. H. Platelets extracts, fibrin formation and interaction of purified prothrombin and thromboplastin. Amer. J. Physiol. 154: 140 1948;
• 8 Johnson S. A, Smathers W. M, Schneider C. L. Platelets and their plasma cofactor activity in the activation of purified prothrombin. Amer. J. Physiol. 170: 631 1952;
• 9 Conley C. L. Platelets in clot retraction. In: Johnson S. A, Monto R. W, Rebuck J. W, Horn R. C. (ed.): The Blood Platelets. X. int. Symp. Henry Ford Hospital, Detroit. Little. Brown & Co; Boston: 1961
• 10 James T. N, Johnson S. A, Monto R. W. The physiology and morphology of blood coagulation in polycythemia vera. J. appl. Physiol. 15: 1049 1960;
• 11 Johnson S. A, McKenna J. L, Husten J. H, Monto R. W, James T. N. Current knowledge of thrombosis and blood coagulation. In: James T. N. (ed.), Etiology of myocardial infarction. X. int. Symp. Henry Ford Hospital, Detroit. (In press, 1962.)
• 12 Hand R. A, Chandler A. B. Atherosclerotic metamorphosis of autologous pulmonary thromboemboli in the rabbit. Amer. J. Path. 40: 469 1962;
• 13 Wessler S, Reimer S. M, Freiman D. G. Thrombosis inducing factors in serum. Thrombos. Diathes. haemorrh. (Suppl) 04: 201 1960;
• 14 Ruegsegger P, Nydick I, Hutter R. C, Freiman A. H, Bong N. W, Cliffton E. E, LaDue J. S. Fibrinolytic (Plasmin) Therapy of Experimental Coronary Thrombi with Alteration of the Evolution of Myocardial Infarction. Circulation 19: 7 1959;
• 15 Holemans R, Gross R. Influence of blood platelets on fibrinolysis. Thrombos. Diathes. haemorrh. 06: 196 1961;
• 16 Johnson S. A, Caldwell M. J, Priest E. M. Effect of oral anticoagulant (Marcoumar) on prothrombin and related components in blood coagulation. Circulât. Res. 05: 252 1957;
• 17 Mertz E. T, Owen Jr C. A. Imidazole buffer: its use in blood clotting studies. Proc. Soc. exp. Biol. (N. Y) 43: 204 1940;
• 18 Schneider C. L, Claxton E. B, Hughes C. H, Johnson S. A. Bovine platelets in large quantities. Amer. J. Physiol. 179: 236 1954;
• 19 Ware A. G, Seegers W. H. Two-stage procedure for the quantitative determination of prothrombin concentration. Amer. J. clin. Path. 19: 471 1949;
• 20 Johnson S. A, Schneider C. L. Existence of antifibrinolysin activity in platelets. Science 117: 229 1953;
• 21 Sherry S, Alkjaersig N. Studies on the fibrinolytic enzyme of human plasma. Thrombos. Diathes. haemorrh. 01: 264 1957;