Specific binding of thrombin by human peripheral blood monocytes: possible role in the clearance of activated clotting factors from the circulation.

摘要: Abstract The possibility that human PBM might specifically bind several proteins of the coagulation mechanism was studied in vitro. Purified preparations thrombin, AT III, TH-AT III complex, and prothrombin were radiolabeled with Na[ 125 I] incubated monocyte monolayers had been isolated from whole blood by Ficoll-Paque sedimentation gradient adherence to plastic tissue culture wells. Specificity binding determined its suppression presence excess concentrations appropriate nonradiolabeled protein. found thrombin but did not or prothrombin. Further characterization showed uptake time- temperature-dependent, saturable, reversible, suggesting an active, receptor-mediated process. Scatchard analysis [ I]thrombin increasing two populations receptors: a high-affinity receptor K d = 3.4 × 10 −9 M low-affinity 1.3 M. These studies indicate may play role clearance activated clotting factors circulation serve as experimental model study RES defense against thrombosis.