A STUDY ON THE CONVERSION OF FIBRINOGEN TO FIBRIN

Abstract

Two different fibrins have been demonstrated based on their solubility in dilute acids and alkalies. The fibrin obtained by defibrination of whole beef blood or by addition of Ca to oxalated or citrated beef plasma is called Ca-fibrin. The fibrin obtained by clotting oxalated or citrated beef plasma with beef thrombase is called thrombase fibrin (T-fibrin). Ca-fibrin is insoluble but swells into a transparent jelly in 0..03% HC1 and is insoluble in 0.5% Na2CO3. T-fibrin is soluble in these reagents. The solubility relationships between Ca-fibrin and T-fibrin also exist in the fibrins from other spp., i.e., dog and rabbit. The precipitate which forms during the storage of oxalated or citrated beef plasma has the solubility of T-fibrin. The clotting of oxalated or citrated beef plasma by thrombase, trypsin, papain, Fer de Lance venom, clotting globulin and ninhydrin produces T-fibrin; these fibrins are soluble in 0.03% HC1. Ca ions are necessary for the in vitro formation of Ca-fibrin. Ca ions convert T-fibrin into Ca-fibrin. This effect is not a specific one, since Sr ions will also produce this conversion but Ba or Mg ions will not. A serum factor besides the Ca ion is also necessary for the in vitro formation of Ca-fibrin. This factor is not present in the purified serum protein fractions. The following equations illustrate the in vitro mechanism in the conversion of fibrinogen to fibrin: Fibrinogen + Thrombase ->[image] T-fibrin T-fibrin + ionic calcium+Serum factor ->[image] Ca-fibrin.