The active and the inactive plasminogen activator inhibitor from XXXX endothelial cell conditioned medium are immunologically and functionally related to each other.

@entity1 @entity214
In @entity1 endothelial cell conditioned medium a fast-acting inhibitor of tissue-type plasminogen activator and urokinase has been detected. Moreover, an inactive inhibitor of these plasminogen activators is present, that can be activated by denaturing agents such as @entity214 ( @entity214 ). The mutual relationship between these inhibitors was studied. The fast-acting plasminogen activator inhibitor from @entity1 endothelial cell conditioned medium was purified in a complex with tissue-type plasminogen activator by immune adsorption, using an immobilized anti-tissue-type plasminogen activator antibody. With the complex as an antigen, specific antibodies were raised against this inhibitor in rabbits. The antiserum immunoreacted with both the inactive and the fast-acting plasminogen activator inhibitor. Endothelial cell conditioned medium (containing the inactive plasminogen activator inhibitor) was treated with @entity214 and the inhibitory activity that emerged was purified. The @entity214 -generated product formed complexes with tissue-type plasminogen activator with the same molecular mass as those formed with the fast-acting inhibitor. Moreover, the inhibitory activity generated by @entity214 treatment showed the same kinetic behaviour with tissue-type plasminogen activator as did the fast-acting inhibitor. These data show that the fast-acting and the inactive plasminogen activator inhibitor are immunologically and functionally related to each other, and probably represent different molecular forms of the same protein.
