title: Immediate release of a nitric oxide-like factor from bovine aortic endothelial cells by Escherichia coli lipopolysaccharide.
abstract: Incubation of human washed platelets with bovine aortic endothelial cells (ECs) treated with indomethacin resulted in an inhibition of thrombin-induced platelet aggregation that was dependent on the number of ECs added. Preincubation of ECs with Escherichia coli lipopolysaccharide (LPS; 0.5-2.0 micrograms/ml) for 1 min significantly enhanced their inhibitory activity. This effect was potentiated by superoxide dismutase (60 units/ml) and reversed by oxyhemoglobin (5-10 microM), indicating that the inhibition was due to the release of endothelium-derived relaxing factor (nitric oxide). When the ECs were pretreated with NG-monomethyl-L-arginine (30-300 microM) before LPS, the antiaggregatory activity was strongly reduced. The reduction of activity by NG-monomethyl-L-arginine was reversed by L-arginine (100 microM) but not by D-arginine (100 microM). Under similar conditions, LPS also enhanced the antiaggregatory activity of ECs grown on beads. The immediate enhancement by LPS of the release of endothelium-derived relaxing factor from endothelial cells may contribute to the rapid fall in blood pressure associated with endotoxin shock in vivo.
authors.affiliation: William Harvey Research Institute, Saint Bartholomew's Hospital Medical College, London, United Kingdom.
authors.forename: D
authors.initials: D
authors.lastname: Salvemini
authors.forename: R
authors.initials: R
authors.lastname: Korbut
authors.forename: E
authors.initials: E
authors.lastname: Anggård
authors.forename: J
authors.initials: J
authors.lastname: Vane
mesh_terms: D000818:Animals; D001011:Aorta; D001920:Bradykinin / Q000494:pharmacology; D002417:Cattle; D002470:Cell Survival; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004926:Escherichia coli; D007213:Indomethacin / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D010974:Platelet Aggregation; D010975:Platelet Aggregation Inhibitors; D013482:Superoxide Dismutase / Q000494:pharmacology
chemical_list: D008070:Lipopolysaccharides; D010975:Platelet Aggregation Inhibitors; D009569:Nitric Oxide; D013482:Superoxide Dismutase; D001920:Bradykinin; D007213:Indomethacin