Print Email Facebook Twitter Studies on the acute release of tissue-type plasminogen activator from human endothelial cells in vitro and in rats in vivo: Evidence for a dynamic storage pool Title Studies on the acute release of tissue-type plasminogen activator from human endothelial cells in vitro and in rats in vivo: Evidence for a dynamic storage pool Author van den Eijnden-Schrauwen, Y. Kooistra, T. de Vries, R.E.M. Emeis, J.J. Gaubius Instituut TNO Publication year 1995 Abstract The process of acute release of tissue-type plasminogen activator (tPA) is important in locally speeding up fibrinolysis. Using a sensitive enzyme- linked immunosorbent assay for tPA, we investigated the acute release of tPA from cultured human umbilical vein endothelial cells. The addition of thrombin (0.003 to 3 NIH U/mL) caused the dose-dependent release of noncomplexed, enzymatically active tPA into the medium. The amount of tPA released into the medium by thrombin was similar to the difference in the amounts of tPA present in extracts from thrombin-treated cells and control cells. The process of acute release of tPA was complete in 1 minute, whereas the concomitant release of yon Willebrand factor into the medium was slightly slower (maximum after 3 minutes). By increasing (c.q. decreasing) tPA synthesis, it was found that the amount of tPA constitutively secreted, the amount acutely released, and the amount in cell extracts were increased (c.q. decreased) to the same extent. The same relation was found in vivo. When rats were protreated with cholera toxin or retinoic acid to increase tPA synthesis, plasma levels of tPA were increased, whereas acute release of tPA, as induced by bradykinin, was increased to the same extent. Acutely released tPA and constitutively secreted tPA were liberated from different pathways in human umbilical vein endothelial cells; tPA had, relative to the in vivo situation, a short residence time in the acutely releasable pathway. Subject AnimalCholera ToxinEndothelium, VascularHumanRatsThrombinTissue Plasminogen ActivatorTretinoinUmbilical Veins To reference this document use: http://resolver.tudelft.nl/uuid:175702de-60c0-4267-8c4c-077f27c51ab8 TNO identifier 232886 ISSN 0006-4971 Source Blood, 85 (12), 3510-3517 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.