title: Active-site-dependent, thrombin-induced release of adenine nucleotides from cultured human endothelial cells.
abstract: The effect of thrombin on release of adenine nucleotides is studied in cultured cell monolayers from the human umbilical vein. Thrombin-induced release of radioactivity from endothelial cells is dose-dependent and saturable with maximal response seen at 1 x 10(-8) M thrombin. The products are identified by thin-layer chromatography as adenine nucleotides. Diisopropylphosphoryl thrombin, which is enzymatically inactive, does not cause release of tritium. A 50-fold excess of diisopropylphosphoryl-thrombin, despite causing 98 percent inhibition of binding of 125I-thrombin to its high-affinity binding sites, does not inhibit thrombin-induced release. We conclude that (1) thrombin causes release from endothelial cells of adenine nucleotides and that (2) high-affinity, active-site-independent binding of thrombin is not involved in this process.
mesh_terms: D000227:Adenine Nucleotides / Q000378:metabolism*; D000241:Adenosine / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001095:Arachidonic Acids / Q000378:metabolism; D001665:Binding Sites; D002478:Cells, Cultured; D002855:Chromatography, Thin Layer; D004727:Endothelium / Q000166:cytology; D006801:Humans; D013917:Thrombin / Q000031:analogs & derivatives / Q000494:pharmacology*; D014316:Tritium
chemical_list: D000227:Adenine Nucleotides; D001095:Arachidonic Acids; D014316:Tritium; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D013917:Thrombin; C027962:diisopropylphosphoryl-thrombin; D000241:Adenosine