In Vitro and in Vivo Induction of Cryofibrinogen and “Paracoagulation” by Reptilase

Abstract

SummarySmall doses of Reptilase, a snake venom enzyme which exclusively liberates fibrinopeptide A from fibrinogen, leads to formation of cryofibrinogen as well as ethanol- and protamine-precipitability of plasma both in vitro and in vivo. Precipitates obtained in vitro were shown to contain both fibrinogen and fibrin monomer. At 20° C Reptilase-treated fibrinogen solutions contained complexes with a sedimentation rate of 11-11.6 s20W, similar to those observed after thrombin. The artificial production of cryofibrinogenemia in volunteers is discussed in relation to spontaneously occurring cryofibrinogenemias in patients with intravascular coagulation.

Release of Plasminogen Activator by Batroxobin

“…This was also found by other investigators [5], In the isolated perfused pig ear, batroxo bin at a concentration of 0.25 BU/ml perfu sion solution caused a release of fibrinolytic activity which was suppressed by the addi tion of IgG antibodies against human v-PA (table I). The activator release increased in a dose-dependent manner up to 1 BU batroxobin/ml (table II).…”

Characterization of Cryofibrinogen Isolated from Patients’ Plasma

“…It was also shown that cryofibrinogen can be produced in normal plasma after the addition of thrombin or thrombin-like enzymes or in animals following the infusion of agents that induce fibrin formation. These observations, as well as the deter mination of the fibrinopeptides content of such precipitates, demonstrated that cryofibrinogen is a complex of fibrinogen with fibrin-lacking fibrino-peptides A (3,16,17). Later it was shown that the cryofibrinogen of a patient with DIC contained, in addition to fibrinogen, a nonclottable com ponent which was identified as cold-insoluble globulin (CIg), currently known as fib'ronectin (10).…”