Abstract
The effects on fibrinolysis of purified normal human high density lipoproteins (HDL) and their apolipoproteins (apo) were assessed in an in vitro system containing urokinase, plasminogen and fibrin. HDL significantly increased lysis area of plated fibrin compared to controls. The hydrolysis of a chromogenic substrate (S-2251: H-D-Val-Leu-Lys-pNA) specific to plasmin or urokinase activated plasminogen was higher in the presence of apo A-I, apo HDL2, and apo HDL3. These data suggest that the major protein of HDL—apo A-I— and possibly certain minor apo constituent(s) of HDL may participate in the fibrinolytic process and propose a new function for HDL.
