Hexose Content of Bovine Fibrinogen and Fibrin, and Evidence against its Release by Fibrin Stabilizing Factor

Abstract

FIBRINOGEN from several species contains a small amount of hexoses as well as some glucosamine and sialic acid¹. It has been shown that a slight decrease in its hexose content occurs when fibrinogen is clotted with thrombin^2–6, though the fibrinopeptides released by thrombin contain no carbohydrate^5,7. Recently, evidence has been put forward that this loss of hexose, and of sialic acid, is related to the action of fibrin stabilizing factor (FSF)^1,8–11. Such evidence is, however, difficult to reconcile with the earlier findings of a loss of hexose in experimental conditions which, because of the absence of Ca⁺⁺ ions, would not have allowed fibrin stabilization to occur^3–6. Indeed, the fibrin clots described in one report were clearly not stabilized as 1 per cent monochloroacetic acid was used to dissolve them⁵. Furthermore, the failure to demonstrate hexose in clot liquors after clotting fibrin monomer in the presence of FSF and Ca⁺⁺ ions¹² makes it difficult to ascribe the release of hexose, if any, to the action of FSF. The following experiments were made in an attempt to resolve these different findings.