The influence of haemoglobin on the fibrinolytic enzyme system

Babesia bovis (argentina): observations of coagulation parameters, fibrinogen catabolism and fibrinolysis in intact and splenectomized cattle

The results of this paper indicate that cattle infected with B. bovis (argentina) have a markedly altered and activated coagulation system. A degree of thrombin activation occurs due partly to release of thromboplastin-like substances from lysed erythrocytes but due primarily to activation of kallikrein by babesial proteases. This produces a hyperfibrinogenaemia, particularly in intact cattle, with soluble fibrin complexes constituting up to one-third of the total fibrinogen concentration. High molecular weight non-coagulable fibrinogen-like proteins are detected terminally but more so in splenectomized cattle. Plasminogen concentration decreases in splenectomized but not intact cattle while low molecular weight fibrinogen degradation products are not easily detected. It is suggested that a hypercoagulable intermediate state with little or no fibrin deposition occurs rather than terminal disseminated intravascular coagulation.

Acute Babesia bigemina infection: changes in fibrinogen catabolism

Plasma from cattle infected with Babesia bigemina contained soluble fibrin in monomer and high molecular weight complex forms. Fibrin(ogen) degradation products were not constantly detected and there appeared to be little or no evidence to suggest fibrinolysis or fibrin deposition. It is suggested that classical disseminated intravascular coagulation does not occur during B. bigemina infection.

A cold precipitable fibrinogen complex in the plasma of cattle dying from infection with Babesia argentina

Plasma from cattle dying from infection with Babesia argentina formed a cold precipitable gel when stored at 4 degrees C. Immunodiffusion and electrophoresis showed the soluble phase of the gel to consist mainly of a fibrinogen-like protein with small amounts of other plasma proteins. Gel filtration and specific clotting assays demonstrated a wide molecular weight spectrum of fibrinogen-like proteins, most of which appeared to be soluble fibrin in either monomer or complex forms. The possibility that proteolytic enzymes might be responsible for the formation of the gel is discussed.