Characterization of a soluble plasminogen activator from kidney cell cultures

Abstract

Primary cultures of monkey kidney cells and cultures of an established line of dog kidney cells have been shown to accumulate a fibrinolytic agent during the growth of the cells in serum-free media. A differential fibrin plate assay has been used to demonstrate this and show that the agent is an activator of plasminogen and not a fibrin-olysokinase. The active material has been concentrated and its properties as an activator confirmed by a caseinolytic assay method. The plasminogen activator from both cultures has been shown by high speed centrifuga-tion to be in solution and its properties have been found to be similar to urokinase.