Structural Alterations in Fibrin Clots with Dextran

Summary

Theoretical reasoning underlying physicochemical measurement of opacity ratio of fibrin clots, i. e. the ratio of turbidity at 350 nm and 608 nm is given. From such considerations it is deduced that opacity ratio may be used to characterise clot morphology : opacity ratio will be inversely related to the size of inhomogeneities formed in the clot.

A highly reproducible technique for the measurement of opacity ratio is described. Additions of small amounts of dextran to fibrinogen solution consistently decrease the opacity ratio of clots made subsequently. This decrease which indicates that the inhomogeneities forming in such fibrin clots are larger than control, is independent of the molecular weight of dextran, but is related to the logarithm of the final dextran concentration. Both thrombin and fibrinogen concentrations are also determinants of opacity ratio. Electron microscopy of fibrin clots made in the presence of dextran confirms that such clots have an altered morphology. Properties of clots in relationship to their structural morphology are discussed.

• References

• 1 Bonner J, and Walsh J. 1972; Prevention of thrombosis after pelvic surgery by British dextran 70. Lancet 1: 614.
• 2 Dhall D. P, and Beyce W. A. J. 1970 Effect of dextran on kinetics of fibrin formation. 6th European Conference on Microcirculation, Aalborg, P. 375.
• 3 Dhall D. P, and Muzaffar T. Z. 1972; Dextran 70 and post-operative peripheral venous thrombosis. Lancet 1: 799.
• 4 Edsall J. T, and Lever W. F. 1951; Effect of ions and neutral molecules on fibrin clotting. The Journal of Biological Chemistry 191: 735.
• 5 Ferry J. D, and Morrison P. R. 1947; Preparation and properties of serum and plasma proteins. VIII. The conversion of human fibrinogen to fibrin under various conditions. Journal of the Americal Chemical Society 69: 388.
• 6 Ferry J. D, and Shtjlmann S. 1949; The conversion of fibrinogen to fibrin. I. Influence of hydroxyl compounds on clotting time and clot opacity. Journal of the American Chemical Society 71: 3198.
• 7 Gay P. 1967. The measurement of refractive indices microscopically. An Introduction to Crystal Optics. Longmans Green and Co. Ltd.; 94.
• 8 Heller W. J. 1957; Theoretical investigations of the light scattering by colloidal spheres. II. Accurate interpolations of theoretical turbidity data. Journal of Chemical Physics 26: 920.
• 9 Kuckenberg L. J. L. 1962; Experimental use of Macrodex as a prophylaxis against postoperative thromboembolism. Bulletin Société Internationale De Chirurgie 21: 501.
• 10 Lambie J, Barber D, Dhall D. P, and Matheson N. A. 1970; Dextran 70 in the prophylaxis of post-operative venous thrombosis. A controlled trial British Medical Journal 2: 144.
• 11 Luft J. H. 1961; Improvements in epoxy resin embedding methods. The Journal of Biophysical and Biochemical Cytology 9: 409.
• 12 Muzaffar T. Z, Youngson G. G, Bryce W. A. J, and Dhall D. P. 1972 Studies on fibrin formation and effects of dextran. Thrombosis et Diathesis Haemorrhagica. This edition.