title: Regulation of the fibrinolytic system of cultured human vascular endothelium by interleukin 1.
abstract: We examined the effects of human interleukin 1 (IL-1) on the production of fibrinolytic components by cultured human vascular endothelium. Conditioned media collected from IL-1-treated (5 U/ml, 24 h) monolayers exhibited decreased tissue-type plasminogen activator (tPA) activity and increased plasminogen activator inhibitor (PAI) activity, as assessed by fibrin and reverse fibrin-autography. Quantitative immunological assays revealed a 35% decrease in tPA antigen and a 360% increase in active PAI antigen, after incubation for 24 h with 0.6 U/ml IL-1. Maximal effects (approximately 50% decrease in tPA antigen; 400-800% increase in active PAI antigen) were observed with 2.5-5 U/ml IL-1. Changes in tPA and PAI reached a maximum at approximately 24 h and persisted for greater than 48 h. IL-1 induction of endothelial procoagulant activity was more rapid and transient, peaking by 6 h and subsiding by 24 h. Natural monocyte-derived IL-1 and two species of recombinant IL-1 had comparable effects. Heat and polymyxin-B treatments differentiated IL-1 actions from those of endotoxin, which promoted similar endothelial alterations. IL-1 effects on endothelial procoagulant and fibrinolytic activities may contribute to the generation and maintenance of fibrin in pathophysiological settings in vivo.
mesh_terms: D001780:Blood Coagulation Tests; D002478:Cells, Cultured; D004727:Endothelium / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D005342:Fibrinolysis; D006023:Glycoproteins / Q000096:biosynthesis; D006801:Humans; D007375:Interleukin-1 / Q000502:physiology*; D007700:Kinetics; D015849:Plasminogen Inactivators; D011994:Recombinant Proteins / Q000502:physiology; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis; D014471:Umbilical Veins
chemical_list: D006023:Glycoproteins; D007375:Interleukin-1; D015849:Plasminogen Inactivators; D011994:Recombinant Proteins; D010959:Tissue Plasminogen Activator