Effect of in vivo produced fibrinogenfibrin intermediates on viscosity of human blood

Abstract

The influence of in vivo produced soluble fibrinogen-fibrin intermediates (FFI) on blood viscosity and suspension stability was studied using a human in vivo model, Low doses of Defibrase, the purified Bothrops atrox venom, produce coagulation changes similar to those seen in intravascular coagulation and thrombosis, including cryofibrinogenemia, ethanol gelation of plasma and FFI-complexes as demonstrable by gel filtration and ultracentrifugation. Fifteen volunteers recieved Defibrase and four subjects glucose infusions. Symptoms were not provoked. Blood viscosity, although unchanged at body temperature, was impressively increased at 22°C. The erythrocyte sedimentation rate was decreased at both temperatures. FFI-complexes are usually assayed at room temperature. Their formation is likely to be responsible for the increased viscosity at 22°C. In view of the unchanged viscosity at body temperature it appears probable that FFI are not present in high-molecular form at 37°C. FFI-complexes may thus largely represent an in vitro phenomenon with little if any bearing on hemorheology in vivo.