Activation of Porcine Plasminogen by Human Urokinase

Abstract

Lauritsen, O. S. Activation of Porcine Plasminogen by Human Urokinase. Scand. J. clin. Lab. Invest. 22, 239-246, 1968.

A plasminogen preparation from swine blood was activated by human urokinase. The preparation was solubilised and stabilised by an appropriate concentration of lysine. Two methods are described for the measurement of the content of plasminogen in the preparation: a proteolytic method using casein as substrate, and an esterolytic method using benzoyl-arginine ethyl ester as substrate. The two methods gave identical results, as related to a purified plasmin preparation. The addition of casein to a plasminogen-urokinase mixture inhibited the activation but did not stop it. A complete inhibition could be effectuated by the addition of ϵ-amino caproic acid in a concentration inhibiting plasmin activity only to a moderate extent. The concentration of reagents could be adjusted so that the amount of plasmin formed within certain limits was proportional to activation time and concentration of urokinase; however, activation also depended upon concentration of plasminogen.

Key Words:

• Casein hydrolysis
• ester hydrolysis
• ϵ-amino caproic acid
• fibrinolysis
• lysine
• plasmin
• plasminogen activation
• urokinase