Studies on the Release of a Plasminogen Activator Inhibitor by Human Platelets

Summary

The relative contribution of platelets to plasminogen activator inhibitor (PA-inhibitor) activity in blood was investigated. From the difference in PA-inhibitor levels in platelet-poor plasmas of 12 donors (3 ± 1 U/ml, mean ±95% confidence limits) and in the corresponding platelet-rich plasmas after induction of platelet aggregation by collagen, ADP or epinephrine (7 ± 1 U/ml), it may be concluded that a greater amount of PA-inhibitor in blood is associated with platelets than with plasma. In collagen-stimulated platelets maximal release of PA-inhibitor and of beta-thromboglobulin (β-TG) was attained within fifteen seconds, whereas in ADP-stimulated platelets the release of both factors was slower. In platelet-poor plasma no correlation was found between the level of PA-inhibitor and that of P-TG. Thus, the PA-inhibitor found in plasma is not derived from platelets that had been stimulated after blood collection. The rate of complex formation and the Mr of the principal complexes of radioiodinated tissue-type plasminogen activator (t-PA) or urokinase (UK), in platelet-poor plasma, in platelet-rich plasma after platelet aggregation or in an extract of washed platelets was the same. Moreover, complexes of UK or t-PA with plasmatic PA-inhibitor or with the PA-inhibitor(s) from platelets bound to immobilized antibodies against bovine endothelial cell-derived PA-inhibitor. These results show that the PA-inhibitors in plasma and in platelets are very similar or identical.

Key words

Platelets - Plasminogen activator inhibitor

• References

• 1 Collen D. On the regulation and control of fibrinolysis. Thromb Haemostas 1980; 43: 77-89
• 2 Kruithof EK O, Ransijn A, Bachmann F. Inhibition of tissue plasminogen activator by human plasma. In: Progress in Fibrinolysis Davidson JF, Bachmann F, Bouvier CA, Kruithof EK O. (eds.) Vol 6 Churchill Livingstone; Edinburgh: 1983. p 365-369
• 3 Kruithof EK O, Tran-Thang C, Ransijn A, Bachmann F. Demonstration of a fast-acting inhibitor of plasminogen activators in human plasma. Blood 1984; 64: 907-913
• 4 Chmielewska J, Rånby M, Wiman B. Evidence for a rapid inhibitor to tissue plasminogen activator in plasma. Thromb Res 1983; 31: 427-436
• 5 Juhan-Vague I, Moerman B, De Cock F, Aillaud MF, Collen D. Plasma levels of a specific inhibitor of tissue-type plasminogen activator (and urokinase) in normal and pathological conditions. Thromb Res 1984; 33: 523-530
• 6 Verheijen JH, Chang GT G, Kluft C. Evidence for the occurrence of a fast-acting inhibitor for tissue-type plasminogen activator in human plasma. Thromb Haemostas 1984; 51: 392-395
• 7 Wiman B, Chmielewska J, Rånby M. Inactivation of tissue plasminogen activator in plasma. J Biol Chem 1984; 259: 3644-3647
• 8 Thorsen S, Brakman P, Astrup T. Influence of platelets on fibrinolysis: a critical review. Hemat Rev 1972; 3: 123-179
• 9 Joist JH. Platelets and fibrinolysis. Thromb Haemostas 1977; 38: 955-962
• 10 Crawford GP M. Platelets and fibrinolysis. In: Haemostasis, biochemistry, physiology and pathology Ogston D, Bennett B. (eds.) J. Wiley & Son; London: 1977. p 342-353
• 11 Murray J, Crawford GP M, Ogston D, Douglas AS. Studies on an inhibitor of plasminogen activators in human platelets. Br J Haematol 1974; 26: 661-668
• 12 Moore S, Pepper DS, Cash JD. The isolation and characterization of a platelet specific β-globulin (β-thromboglobulin) and the detection of anti-urokinase and antiplasmin released from thrombin-aggregated washed human platelets. Biochim Biophys Acta 1975; 379: 360-369
• 13 Erickson LA, Ginsberg MH, Loskutoff DJ. Detection and partial characterization of an inhibitor of plasminogen activator in human platelets. J Clin Invest 1984; 74: 1465-1472
• 14 Kruithof EK O, Schleuning W-D, Bachmann F. Human tissue-type plasminogen activator: production in continuous serum-free cell culture and rapid purification. Biochem J 1985; 226: 631-636
• 15 Fraker PJ, Speck JC. Protein and cell membrane iodinations with a sparingly soluble chloramide, l,3,4,6-tetrachloro-3a, 6a-diphenylgly-coluril. Biochem. Biophys Res Commun 1978; 80: 849-857
• 16 Kruithof EK O, Ransijn A, Bachmann F. Influence of detergents on the measurement of the fibrinolytic activity of plasminogen activators. Thromb Res 1982; 28: 251-260
• 17 Weiss HJ, Meyer D, Rabinowitz R, Pietu G, Girma J-P, Vicic WJ, Rogers J. PSeudo-Von Willebrand’s disease. New Engl J Med 1982; 306: 326-333
• 18 Verheijen JH, Mullaart E, Chang GT G, Kluft C, Wijngaards G. A simple sensitive spectrophotometric assay for extrinsic (tissue-type) plasminogen activator applicable to measurements in plasma. Thromb Haemostas 1982; 48: 266-269
• 19 Tangen O, Berman HJ, Marfey P. Gel filtration. A new technique for separation of blood platelets from plasma. Thromb Diathes Haemorrh 1971; 25: 268-278
• 20 Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 1970; 227: 680-685
• 21 Travis J, Salvesen GS. Human plasma proteinase inhibitors. Ann Rev Biochem 1982; 52: 655-709
• 22 Kruithof EK O, Tran-Thang C, Bachmann F. The fast-acting inhibitor of tissue-type plasminogen activator in human plasma is also the primary inhibitor of urokinase. Thromb Haemostas 1986; 55: 65-69
• 23 Booth NA, Anderson JA, Bennett B. Platelet release protein which inhibits plasminogen activator. J. Clin Pathol 1985; 38: 825-830
• 24 Golder JP, Stephens RW. Minactivin: a human monocyte product which specifically inactivates urokinase-type plasminogen activator. Eur J Biochem 1983; 136: 517-522
• 25 Vassalli J-D, Dayer J-M, Wohlwend A, Belin D. Concomitant secretion of prourokinase and of a plasminogen activator-specific inhibitor by cultured human monocytes-macrophages. J Exp Med 1984; 159: 1653-1668
• 26 Emeis JJ. Fast hepatic clearance of tissue-type plasminogen activator inhibitor. Thromb Haemostas 1985; 54: 230 (Abstr.)
• 27 Ganguly P. Studies on platelet proteins III. The identity of platelet and serum albumins. Biochim Biophys Acta 1969; 188: 78-88
• 28 James HL, Bradford HR, Ganguly P. Platelet fibrinogen. Identity and initial observations on the mode of its degradation by plasmin. Biochim Biophys Acta 1975; 386: 209-220
• 29 Smariga PE, Maynard JR. Platelet effects on tissue factor and fibrinolytic inhibition of cultured human fibroblasts and vascular cells. Blood 1982; 60: 140-147
• 30 Smariga PE, Maynard JR. Purification of a platelet protein which stimulates fibrinolytic inhibition and tissue factor in human fibroblasts. J Biol Chem 1982; 257: 11960-11965
• 31 Joist JH, Niewiarowski S, Nath N, Mustard JF. Platelet antiplasmin: its extrusion during the release reaction, subcellular localization, characterization and relationship to antiheparin in pig platelets. J Lab Clin Med 1976; 87: 659-669
• 32 Plow EF, Collen D. The presence and release of alpha2-antiplasmin from human platelets. Blood 1981; 58: 1069-1074
• 33 Lockhart MS, Comp PC, Taylor FB. Role of platelets in lysis of dilute plasma clots. J Lab Clin Med 1979; 94: 285-294
• 34 Carroll RC, Radcliffe RD, Taylor FB, Gerrard JM. Plasminogen, plasminogen activator and platelets in the regulation of clot lysis. J Lab Clin Med 1982; 100: 986-996