A Study of Factors Influencing the Enzymatic Elimination of Adenosine Diphosphate in Blood

Summary

The red cells carry by far the greater part of the enzyme systems capable of eliminating adenosine diphosphate found in the blood but this activity is more concentrated in the platelets.

These “ADPase” systems are strikingly stimulated by divalent cations with Mg⁺⁺ being the most effective ion. Ca⁺⁺, while possessing some effect, is antagonistic to Mg⁺⁺ in the platelet system.

A heat stable enhancing factor for the platelet “ADPase” system was shown to be present in platelet poor plasma. This factor was ineffective in preparations obtained from erythrocytes.

• References

• 1 Hellem A.J. The adhesiveness of human blood platelets in vitro. Scand. J. Clin. Invest 1960; 12: 51 Supplement
• 2 Gaarder A.J, onsen J, Laland S, Hellem A.J, Owren P.A. Adenosine diphosphate in red cells as a factor in the adhesiveness of human blood platelets. Nature (Lond.) 1961; 192: 531-532
• 3 Spaet T.H, Zucker M.B. Mechanism of platelet plug formation and the role of adenosine diphosphate. Amer. J. Physiol 1964; 206: 1267
• 4 O’Brien J.R. A comparison of platelet aggregation produced by seven compounds and a comparison of their inhibitions. J. clin. Path 1964; 17: 275
• 5 Grette K. Studies on the mechanisms of thrombin-catalyzed haemostatic reactions in blood platelets. Acta physiol. scand 1962; 56: 195 Supplement
• 6 O’Brien J.R. On the value of using many different platelet “adhesiveness” tests. Thrombos. Diathes. haemorrh. (Stuttg.) Supplement 1967; 26: 185-191
• 7 Haslam R.J, Mills D.C.B. The adenylate kinase of human plasma, erythrocytes and platelets in relation to the degradation of adenosine diphosphate in plasma. Bioch. J 1967; 103: 773-784