PRODUCTION OF PLASMINOGEN-ACTIVATOR INHIBITOR-1 BY HUMAN SAPHENOUS-VEIN ENDOTHELIAL-CELLS SEEDED ONTO ENDARTERECTOMY SURFACES IN-VITRO

Purpose: Endothelial cells produce many biologically important factors that may be used as functional markers, including plasminogen activat ors and their inhibitors (PAI). PAI-1 is a common peptide with a centr al role in the balance of thrombosis and fibrinolysis in vivo, and its production by vascular endothelial cells has been demonstrated for ma ny in vitro cell lines. Methods: The basal rate of PAI-1 release from cultured human adult endothelial cells was studied in both a well-plat e-seeding model and after seeding onto human endarterectomy specimens. The effect of nonspecific stimulation with thrombin on PAI-1 release was examined in well-plate cultures, PAI-1 was measured by enzyme-link ed immunosorbent assay. Results: Cultured human saphenous endothelial cells release PAI-1 constitutively at a steady rate, which can be incr eased in the short term by the addition of thrombin. Conclusion: After seeding onto endarterectomy specimens, seeded endothelial cells relea se significant amounts of PAI-1, which suggests that they retain funct ional integrity and may potentially influence thrombosis in vivo after seeding.