[Plasminogen activator inhibitors from neoplastic tissues].

This article contains a survey of works, published in the last few years on plasminogen activators inhibitors in neoplastic tissues. These inhibitors belong to a heterogenous group of proteins, having different molecular weights and specific ways of acting. They exemplify immunological relationship to known inhibitors of fibrinolysis from normal tissues--i.e. the inhibitors from endothelial cells--(PAI-1) and placental inhibitor--(PAI-2). To PAI-1 type belong: acid-stabile inhibitor of fibrinolysis with Mr 50,000 from HTC hepatoma cells in rats, acid-labile inhibitor Mr 42,770 produced by HepG2 human hepatoma cells; the inhibitor with Mr 54,000 from HT 1080 human cells from fibrosarcoma and single-chain acid-stabile inhibitor with Mr 50,000 from MJZJ melanoma cells. In PAI-2 type we can mention the inhibitor with Mr 47,000 from U-937 histiocytic lymphoma cells.