title: Thrombomodulin activity is found in tissue thromboplastin preparations from placenta and from lung but not from brain.
abstract: Substantial thrombomodulin activity could be detected in tissue thromboplastin preparations from placenta or from lung but not from brain. When the amount of these preparations was adjusted to contain 1 unit of tissue factor activity, up to 0.85 units of thrombomodulin activity could be measured, corresponding to the generation of 17 pmol/ml/min of activated protein C when 1.5 microM human protein C was activated by 20 nM human alpha-thrombin in the presence of 5 mM CaCl2. After treatment by phospholipase C, thrombomodulin activity was reduced in these samples. Addition of mixed brain procoagulant phospholipids partially restored thrombomodulin activity in the phospholipase C-treated samples. These results emphasize the role of phospholipids in the expression of optimal thrombomodulin activity in tissue thromboplastin preparations from placenta or from lung.
mesh_terms: D001923:Brain Chemistry; D005169:Factor VIII / Q000032:analysis*; D005260:Female; D006801:Humans; D008168:Lung / Q000032:analysis*; D010743:Phospholipids / Q000502:physiology; D010920:Placenta / Q000032:analysis*; D011956:Receptors, Cell Surface / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018179:Receptors, Thrombin; D013925:Thromboplastin / Q000302:isolation & purification*; D014020:Tissue Extracts / Q000032:analysis
chemical_list: D010743:Phospholipids; D011956:Receptors, Cell Surface; D018179:Receptors, Thrombin; D014020:Tissue Extracts; D005169:Factor VIII; D013925:Thromboplastin