Stimulated Platelet Aggregation, Thromboxane B₂ Formation and Platelet Sensitivity to Prostacyclin - A Critical Evaluation

Summary

Platelets have been implicated in the development of atherosclerotic and thrombotic vascular diseases. Evaluation of platelet aggregation in relation to endogenously formed compounds which affect platelet function may provide information of clinical and pharmacological relevance. We describe a method in which thromboxane B₂ (TXB₂) formation was analyzed following stimulation of platelet-rich plasma (PRP) with ADP, 1-epinephrine, collagen, and arachidonic acid. In addition, we determined platelet sensitivity to prostacyclin following ADP- and collagen-induced platelet aggregation. The parameters under study were found to depend on the platelet count in PRP, on the type and dose of the aggregating agent used, and on the test time after blood sampling. By standardization of these variables, a reliable method was established which can be used in clinical and pharmacological trials.

Keywords

Platelet aggregation - Thromboxane B₂ formation - Aggregating agents - Prostacyclin-sensitivity

• References

• 1 Schafer AI, Handin RI. The role of platelets in thrombotic and vascular disease. Progress in Cardiovascular Diseases 1979; 22: 31-52
• 2 Moncada S, Vane JR. Unstable metabolites of arachidonic acid and their role in haemostasis and thrombosis. Brit Med Bull 1978; 34: 129-135
• 3 Fitzpatrick FA, Gorman RR. Platelet-rich plasma transforms exogenous prostaglandin endoperoxide H₂into thromboxane A₂ . Prostaglandins 1977; 14: 881-889
• 4 Sors H, Pradelles P, Dray F, Rignaud M, Maclouf J, Bernard P. Analytical methods for thromboxane B₂measurement and validation of radioimmunoassay by gas chromatography - mass spectrometry. Prostaglandins 1978; 16: 277-290
• 5 Koh H, Inone A, Mashimo N, Numano F, Maezawa H. A radioimmunoassay of thromboxane B₂with thromboxane B₂-¹²⁵J-tyramide and its application to the study on the thromboxane B₂formation during platelet aggregation. Thromb Res 1980; 17: 403-413
• 6 Zmuda A, Dembinska-Kiec A, Chytkowski A, Gryglewski RJ. Experimental atherosclerosis in rabbits: platelet aggregation, thromboxane A₂generation and antiaggregatory potency of prostacyclin. Prostaglandins 1977; 1035-1042
• 7 Harrison MJ G, Emmons PR, Mitchell JR A. The variability of human platelet aggregation. J Atherosclerosis Res 1967; 07: 197-205
• 8 O’Brien JR. Variability in the aggregation of human platelets by adrenaline. Nature 1964; 202: 1188-1190
• 9 Bom GV R. Aggregation of blood platelets by adenosine diphosphate and its reversal. Nature 1962; 194: 927-929
• 10 Smith JB, Ingermann C, Silver MJ. Persistence of thromboxane A₂-like material and platelet release-inducing activity in plasma. J Clin Invest 1976; 58: 1119-1122
• 11 Scherer B, Siess W, Weber PC. Radioimmunological and biological measurement of prostaglandins in rabbit urine: decrease of PGE₂excretion at high NaCl intake. Prostaglandins 1977; 13: 1127-1139
• 12 Rossi EC, Louis G. A time dependent increase in the responsiveness of platelet-rich plasma to epinephrine. J Lab Med 1975; 85: 300-306
• 13 Feinberg H, Sandler WC, Scoren M, LeBreton GC, Grossman B, Born GV R. Movement of sodium into human platelets induced by ADP. Biochim Biophys Acta 1977; 470: 317-324
• 14 Blackwell GJ, Duncombe WG, Flower RJ, Parsons MF, Vane JR. The distribution and metabolism of arachidonic add in rabbit platelets during aggregation and its modification by drugs. Br J Pharmac 1977; 59: 353-366
• 15 Hamberg M, Svensson J, Samuelsson B. Thromboxanes: a new group of biologically active compounds derived from prostaglandin endoperoxides. Proc Natl Acad Sd USA 1975; 72: 2994-2998
• 16 Dray F, Siess W. Radioimmunoassay of prostanoids. In “Prindples of competitive protein binding assays”. editor Odell W. 2nd . edition in press 1981
• 17 Oelz O, Oelz R, Knapp HR, Sweetman BJ, Oates IA. Biosynthesis of prostaglandin D₂ . Formation of prostaglandin D₂by human blood platelets. Prostaglandins 1977; 13: 225-234
• 18 Smith JB, Ingermann C, Kocsis JJ, Silver MJ. Formation of prostaglandins during the aggregation of human blood platelets. J Clin Invest 1973; 52: 965-969
• 19 Samuelsson B, Hamberg M, Malmsten C, Svensson J. The role of prostaglandin endoperoxides and thromboxanes in platelet aggregation. In: Advances in Prostaglandin and Thromboxane Research. Samuelsson B, Paoletti R. eds. Raven Press; NY: 1976. Vol 2. p 737-746
• 20 Siess W, Roth P, Scherer B, Kurzmann I, Böhlig B, Weber PC. Platelet membrane fatty adds, platelet aggregation and thromboxane formation during a mackerel diet. Lancet 1980; 1: 441-444
• 21 Lorenz R, Siess W, Weber PC. Effects of very low versus standard dose acetyl-salicylic add, dipyridamole and sulfinpyrazone on platelet function and thromboxane formation in man. Europ J Pharmacol. 1981. in press