Dextrans and fibrin morphology.

Abstract

THROMBIN clotting time is accelerated in the presence of small amounts of dextran1, although dextran has a significant anti-thrombotic effect2. To resolve this paradox Dhall and Bryce3 used a turbidimetric technique to examine the clotting of platelet-poor plasma by thrombin, and showed that small amounts of dextran shortened the induction phase before the appearance of fibrin, accelerated the development of turbidity and enhanced its equilibrium value. They concluded that the structural inhomogeneities normally developed during clotting are rendered coarser in the presence of dextran. We have examined the effect of dextran during the clotting of purified fibrinogen in artificial media; turbidimetric and ultra-structural studies on such fibrin clots confirm the predictions made on the basis of physico-chemical studies. We have made turbidimetric measurements during the clotting of platelet-poor plasma after dextran infusion in man, and these suggest that dextran has a similar action in vivo.