Chemorheological Studies of the Effect of Heparin on the Course of Coagulation

Summary

The influence of sodium heparin on viscoelastic change during coagulation was determined in vitro for whole blood samples from ten normal subjects at heparin concentrations ranging from 0 to 1.45 units/(ml whole blood). A four-parameter chemorheological model was used to describe the time course of coagulation as measured by the Weissenberg Rheogoniometer. One parameter compares closely with the whole blood activated partial thromboplastin time, while the other three may be related to the chemical kinetics of clotting.

The chemorheological model and experimental techniques were then tested in a dog preparation. It was found that rheological measurements are more self-consistent than either thrombelastography or the activated partial thromboplastin time for the assay of in vivo heparin in two dogs.

^* Address: Box 6173, Station B, Vanderbilt University, Nashville, Tennessee 37235, U. SA.

• References

• 1 Blakeley J. A. 1968; A Rapid Bedside Method for the Control of Heparin Therapy. Canadian Medical Association Journal 99: 1072.
• 2 Brigham K, Woolverton W, Blake L, and Staub N. 1974; Increased Sheep Lung Vascular Permeability Caused by Pseudomonas Bacteremia. Journal of Clinical Investigation 54: 792.
• 3 Dintenfass L, and Forbes C. D. 1975; Effect of Fibrinogen on Aggregation of Red Cells and on Apparent Viscosity of Artificial Thrombi in Haemophilia, Myocardial Infarction, Thyroid Disease, Cancer and Control Systems: Effect of ABO Blood Groups. Microvascular Research 9: 107.
• 4 Estes J. W. 1970; Kinetics of the Anticoagulant Effect of Heparin. Journal of the American Medical Association 212: 1492.
• 5 Ferry J. D. 1961. Viscoelastic Properties of Polymers.. John Whiley and Sons; New York:
• 6 Glover C. J, Mc Intire L. V, Leverett L. B, Hellums J. D, Brown C. H, and Natelson E. A. 1974; Effect of Shear Stress on Clot Structure Formation. Transactions of the American Society for Artificial Internal Organs 20: 463.
• 7 Glover C. J, Mc Intire L. V, Brown C. H, and Natelson E. A. 1975; a Dynamic Coagulation Studies: Influence of Normal and Abnormal Platelets on Clot Structure Formation. Thrombosis Research 7: 185.
• 8 Glover C. J. 1975 b Dynamic Shear Moduli During Normal and Abnormal Plasma Clot Formation. Report No. 7501 Biomedical Engineering Laboratory, Rice University. Houston:
• 9 Hartert H. 1960 Thrombelastography: Physical and Physiological Aspects.. Copley A. L, and Stainsby G. (eds.) Flow Properties of Blood and Other Biological Systems.. Pergamon Press, Symposium Publications Division. New York:
• 10 Kaibara M, and Fukada E. 1973; a Dynamic Viscoelastic Study of the Formation of Fibrin Networks in Fibrinogen-Thrombin Systems and Plasma. Biorheology 10: 61.
• 11 Kaibara M, and Fukada E. 1973; b The Dynamic Rigidity of Fibrin Gels. Biorheology 10: 129.
• 12 Marchal G, Lerous M. E, and Samama M. 1962. Atlas de Thrombo dynamo graphic.. Service de Propagande Edition, Information; Paris:
• 13 Marquardt D. W. 1963; An Algorithm for Least-Squares Estimation of Nonlinear Parameters. Journal of the Society for Industrial and Applied Mathematics 11: 431.
• 14 Overholser K. A, Itin J. P, Harris T. R, and Brown D. R. 1974 Rheological Studies of Blood Clot Elasticity: Effect of Heparin from Beef Lung and Intestinal Mucosa. Proceedings of the 27th Annual Conference for Engineering in Medicine and Biology Philadelphia: 6-10 October 1974, Vol. 16 , p. 62
• 15 Overholser K. A, Itin J. P, Brown D. R, and Harris T. R. 1975; The Effect of Heparin on the Viscoelasticity of Whole Blood Clots. Biorheology 72: 309
• 16 Roberts W. W, Lorand L, and Mockros L. F. 1973; Viscoelastic Properties of Fibrin Clots. Biorheology 10: 29.
• 17 Treloar L. R. G. 1967. The Physics of Rubber Elasticity.. 2nd edn.. Oxford University Press; London: