Euglobulin clot lysis time

Rats are anesthetized by intraperitoneal injection of 60 mg/kg pentobarbital sodium and placed on a heating pad (37 °C). At the same time, the test solution or the vehicle (controls) is administered intravenously or intraperitoneally. Twenty-five min later, the animals receive another intraperitoneal injection of 12 mg/kg sodium pentobarbital to keep them in deep narcosis for 45 min. 

After the test compound is absorbed, blood is withdrawn from the inferior caval vein exposed by a mid-line excision. Blood (1.8 ml) is removed with a plastic syringe containing 0.2 ml 3.8 % sodium citrate solution. The sample is thoroughly mixed, transferred to a plastic tube and immediately immersed in ice. Plasma is prepared by centrifugation at 2000 x g for 10 min at 2 °C. 

5 ml portion of plasma is added to 9.5 ml of ice-cold distilled water the pH is brought to 5.3 by the addition of 0.13 ml of 1 % acetic acid. The diluted plasma is kept on ice for 10 min and the precipitated euglobulin fraction is collected by centrifugation at 2000 x g for 10 min at 2 °C. The supernatant is discharged and the remaining fluid is removed by drying the tube on a filter paper for 1 min. The euglobulin precipitate is dissolved in 1 ml of 0.12 M sodium acetate solution. 

Aliquots (0.45 ml) of the euglobulin solution are transferred to test tubes, and 0.05 ml thrombin (Test Thrombin, Behring Werke) (25 U/ml) are added. The tubes are transferred to a water bath at 37 °C. The time interval between the addition of thrombin and the complete lysis of the clots is measured. 

The lysis time [min] is determined. The lysis time is shortened when activators of fibrinolysis are increased. 

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I.M.1.9 Euglobulin Clot Lysis Time 266 I.M.3.9 Stasis-Induced Thrombosis... 

Euglobulin Clot Lysis Time (ECLT) Assay 545... 

A series of events such as the platelet aggregation, hbrinogenesis, hbrin adhesion, hbrin aggregation, and vascular inner wall injury are implicated in the thrombosis. Thus the thrombosis, antithrombosis, and thrombolysis may relate to antiplatelet aggregation [96], chemical- and electrical-induced blood vessel injury [97, 98], thread-induced fibrin or platelet adhesion [99], euglobulin clot lysis time [100,101], fibrinolytic area [102], and reduction of thrombus mass [103,104]. 

Urano T, Sakakibara K, Rydzewski A (1990). Relationships between euglobulin clot lysis time and the plasma levels of tissue plasminogen activator and plasminogen activator inhibitor 1. Thromb. Haemost. 63 82-86. 

Into a test tube 8 mm in diameter placed in a water bath at 37°C introduce 0.2 mL of a solution of a reference preparation of urokinase containing 1001.U. per milliliter and 0.1 mL of a solution of thrombin R containing 20 I.U. per milliliter. Add rapidly 0.5 mL of a solution containing 10 mg of bovine euglobulins per milliliter. A firm clot will form in less than 10 s. Note the time that elapses between the addition of the solution of bovine euglobulins and the lysis of the clot. The lysis time will not exceed 15 min. 

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