title: Blood coagulation in fish.
abstract: Blood coagulation systems in cyclostome, elasmobranch, and teleost fish were studied and compared. The plasma of all these fish contained a fibrinogen molecule, capable of being clotted by human thrombin, and a prothrombin molecule, capable of being converted into thrombin which could hydrolyze p-tosyl l-arginine methyl ester. The prothrombin activity could be adsorbed on barium sulfate. Accurate assessment of prothrombin conversion factors is confounded by the "species specificity" of protein-protein interactions, but preliminary observations were made on both the extrinsic and intrinsic clotting schemes. Fish thrombocytes play a central role in the intrinsic conversion of prothrombin to thrombin, and are responsible for clot retraction. The plasma of the smooth dogfish exemplifies a clotting diathesis which can be overcome in vitro by the addition of large amounts of calcium. Under such conditions, other parts of the coagulation scheme become greatly exaggerated, and a very large thrombin generation ensues, subsequently followed by an intense fibrinolysis. A powerful serum inhibition occurs which was shown to be caused by the breakdown products of the fibrinolysis.
authors: Russell F
authors: RF
authors: Doolittle
authors: Douglas M
authors: DM
authors: Surgenor
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives; D001777:Blood Coagulation / Q000502:physiology*; D001780:Blood Coagulation Tests; D001792:Blood Platelets / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism*; D005342:Fibrinolysis; D005399:Fishes / Q000097:blood* / Q000502:physiology*; D006801:Humans; D010949:Plasma; D011516:Prothrombin / Q000378:metabolism*; D013045:Species Specificity; D013917:Thrombin / Q000378:metabolism*; D014106:Tosylarginine Methyl Ester / Q000097:blood*
chemical_list: C026512:arginine methyl ester; D011516:Prothrombin; D005340:Fibrinogen; D014106:Tosylarginine Methyl Ester; D001120:Arginine; D013917:Thrombin; D002118:Calcium