The Novel Effect of a New Prostacyclin Analogue ZK36374 on the Aggregation of Human Platelets in Whole Blood

Summary

Platelet aggregation was studied at 37° C in citrated whole human blood, using the Ultra Flo 100 Whole Blood Platelet Counter. Aggregation was measured as a fall in the number of single platelets following addition of an aggregating agent. At peak aggregation, the fall in the number of platelets induced by ADP (10 μM), collagen (1 μg/ml) or thrombin (0.2 U/ml) was about 90%. When blood was incubated with the prostacyclin- analogue ZK36374, the aggregation responses to ADP, collagen and thrombin were reduced with IC50’S = 0.5, 1.5 and 3 nM respectively and the corresponding IC100’S were: 1, 3 and 12 nM. When ZK36374 was added at peak aggregation, the number of single platelets increased significantly due to disaggregation of preformed platelet aggregates. It is concluded that the present technique represents a rapid, sensitive and more physiological approach for investigating the effects of pharmacological agents on platelet aggregation.

Keywords

Whole blood - Platelet aggregation - Platelet disaggregation - ZK36374 - Ultra Flo 100

• References

• 1 Moncada S, Gryglewski RJ, Bunting S, Vane JR. An enzyme isolated from arteries transforms prostaglandin endoperoxides to an unstable substance that inhibits platelet aggregation. Nature 1976; 263: 663-665
• 2 Moncada S, Vane JR. Pharmacology and endogenous roles of prostaglandin endoperoxides, thromboxane A₂ and prostacyclin. Pharmacol Rev 1978; 30: 293-331
• 3 Aitken JW, Gorman RR, Shebushi RJ. Prevention of blockage of partially obstructed coronary arteries by prostacyclin correlates with inhibition of platelet aggregation. Prostaglandins 1979; 17: 483-494
• 4 Szczelik A, Gryglewski RJ, Nizankowski R, Shawinski S, Glusko P, Korbut R. Prostacyclin therapy in peripheral vascular disease. Thromb Res 1980; 19: 191-199
• 5 Belch JJ F, McArdle B, Pollock JG, Forbes CD, McKay A, Leiberman P, Lowe GD O, Prentice CR M. Epoprostenol (prostacyclin) and severe arterial disease: A double-blind trial. Lancet 1983; 1: 315-317
• 6 Belch JJ F, Newman P, Drury JK, Capell H, Leiberman P, James WB, Forbes CD, Prentice CR M. Successful treatment of Raynaud’s syndrome with prostacyclin. Thromb Haemostas 1981; 45: 255-256
• 7 Belch JJ F, Drury JK, Capell H, Forbes CD, Newman P, McKenzie F, Leiberman P, Prentice CR M. Intermittent epoprostenol (prostacyclin) infusion in patients with Raynaud’s syndrome. Lancet 1983; 1: 313-315
• 8 Moncada S, Vane JR. Arachidonic acid metabolites and the interactions between platelets and blood vessel-walls. N Engl J Med 1979; 300: 1142-1147
• 9 Radegran K, Papaconstantinou C. Prostacyclin infusions during cardiopulmonary bypass in man. Thromb Res 1980; 19: 267-270
• 10 Grimson AE S, Hughes RD, Mellon PJ, Woods HF, Langley PG, Conalese J, Williams R, Weston MJ. Prostacyclin to prevent platelet activation during charcoal haemoperfusion in fulminant hepatic failure. Lancet 1980; 1: 173-175
• 11 Sun FF, Taylor BM. Metabolism of prostacyclin in rat. Biochemistry 1978; 17: 4096-4101
• 12 Dusting GJ, Moncada S, Vane JR. Disappearance of prostacyclin in the circulation of the dog. Br J Pharmacol 1977; 62: 414-415
• 13 Johnson RA, Morton DR, Kinner JH, Gorman RR, McGuire JC, Sun FF, Whittaker N, Bunting S, Salmon JA, Moncada S, Vane JR. The chemical characterisation of prostaglandin X (prostacyclin). Prostaglandins 1976; 12: 915-928
• 14 Nicolaou KC, Barnette WE, Gasic CP, Magolda RL. 6, 9- thioprostacyclin, a stable and biologically potent analogue of prostacyclin (PGI₂). J Am Chem Soc 1977; 99: 7736-7738
• 15 Lefer AM, Trachte GJ, Smith JB, Barnette WE, Nicolaou KC. Circulatory and platelet actions of 6, 9-thiaprostacyclin (PGI₂-S) in the cat. Life Sci 1979; 25: 159-164
• 16 Aiken JW, Shebushi RJ. Comparison in anaesthetized dogs of antiaggregatory and haemodynamic effects of prostacyclin and a chemical stable prostacyclin analogue 6-carba-PGI₂(carbacyclin). Prostaglandins 1980; 19: 629-643
• 17 Schror K, Ohlendorf R, Darius H. Beneficial effects of a new carbacyclin derivative, ZK36374 in acute myocardial ischaemia. J Pharmacol Exp Ther 1981; 219: 243-249
• 18 Schror K, Darius H, Matzky R, Ohlendorf R. The antiplatelet and cardiovascular actions of a new carbacyclin derivative (ZK36374)- equipotent to PGI₂ in vitro. Naunyn-Schmiedeberg’s Arch Pharmacol 1981; 316: 252-255
• 19 Pareti FI, Mannucci PM, Vanasia S, Gandolfi C, Mangielli N, Mills DC B. Vascular and platelet effects of synthetic analogues of prostacyclin. Thromb Haemostas 1981; 46: 69 (Abstr)
• 20 Lumley P, Humphrey PP A. A method for quantitating platelet aggregation and analysing drug-receptor interactions on platelets in whole blood in vitro. J Pharmacol Methods 1981; 6: 153-166
• 21 Han P, Ardlie NG. The influences of pH temperature and calcium on platelet aggregation. Br J Haematol 1974; 26: 373-389
• 22 Born GV R. Quantitative investigation into the aggregation of blood platelets. J Physiol 1962; 162: 67-68
• 23 Born GV R. Aggregation of blood platelets by adenosine diphosphate and its reversal. Nature 1962; 194: 927-929
• 24 Karpatkin S, Charmartz A. Heterogeneity of human platelets. J Clin Invest 1969; 48: 1073-1082
• 25 Haver VM, Gear AR. Functional fractionation of platelets: Aggregation kinetics and glycoprotein labeling of differing platelet populations. Thromb Haemostas 1982; 48: 211-216
• 26 Blackwell GJ, Flower RJ, Russell-Smith N, Salmon JA, Thorogood PB, Vane JR. Prostacyclin is produced in whole blood. Br J Pharmacol 1978; 64: 436 P
• 27 Gaarder A, Jonsen J, Lalands J, Hellem A, Owren PA. Adenosine diphosphate in red cells as a factor in adhesiveness of human blood platelets. Nature 161 192: 531-532
• 28 Harrison MJ G, Mitchell JR. Influence of red blood cells on platelet adhesiveness. Lancet 1966; 2: 1163-1164
• 29 Hellem AJ. The adhesiveness of human blood platelets in vitro. Scand J Clin Lab Invest 1960; 12 suppl 51: 1-117