In Vitro Clumping of Human Platelets by Dextran

Summary

Platelet aggregation in vitro by dextrans of various molecular weights has been examined in platelet rich plasma and in suspensions of human platelets with a turbidi-metric method and microscopy. Addition of dextran to platelet rich plasma and platelet suspensions causes a biphasic effect on the optical density, consisting of an immediate decrease which seems independent of the molecular weight of the dextran and a delayed, time-dependent decrease influenced by it. Microscopically, platelet aggregation by dextran corresponds more closely to the delayed decrease. Aggregation of human platelets by dextran, for which stirring is necessary, is related to the final dextran concentration, is affected by the platelet population and is not spontaneously reversible. Platelet clumping by dextran is of particular interest since dextran has been shown to possess antithrombotic properties.

• References

• 1 Bennett P.N, Dhall D.P, McKenzie F.N, Matheson N.A. Effects of dextran infusion on the adhesiveness of human blood-platelets. Lancet 1001; II: 1966
• 2 Borgstrom S, Gelin L.-E, Zederfeldt B. The formation of vein thrombi following tissue injury Acta chir. scand., suppl. 247 1959
• 3 Born G.V.R. Quantitative investigation into the aggregation of blood platelets. Physiol J. 1962; 162: 67
• 4 Brecher G, Cronkite E.P. Morphology and enumeration of human blood platelets. J. appl. Physiol. 1950; 5: 365
• 5 Bryant M.F, Bloom W.L, Brewer S.S. Experimental study of the antithrombotic properties of dextran of low molecular weight. Amer. Surg. 1963; 29: 256
• 6 Bygdeman S, Eliasson R, Gullbring B. Effects of dextran infusion on the adenosine diphosphate induced adhesiveness and the spreading capacity of human blood platelets. Thrombos. Diathes. haemorrh. (Stuttg.) 1966; 15: 451
• 7 Dhall D.P, Harper D.R, McKenzie F.N, Matheson N.A. Aggregation of human platelets by dextran. Nature (Lond.) 1966; 210: 745
• 8 Gelin L.-E. Rheological disturbances following tissue injury. In: Symposium on Biorheology, Part 4, of the Proceedings of the Fourth International Congress on Rheology. ed A. L. Copley, Lond., Interscience Publishers.
• 9 Haslam R.J. Role of adenosine diphosphate in the aggregation of human blood platelets by thrombin and fatty acids. Nature (Lond.) 1964; 202: 765
• 10 Laurent T.C. The interaction between polysaccharides and other macromolecules. Biochem. J. 1963; 89: 253
• 11 Mitchell J.R.A, Sharp A.A. Platelet clumping in vitro. Brit. J. Haemat. 1964; 10: 78
• 12 Thorsen G, Hint H. Aggregation, sedimentation and intravascular sludging of erythrocytes Acta chir. scand., suppl. 154 1950