Thromb Haemost 1988; 60(02): 148-152
DOI: 10.1055/s-0038-1647020
Original Article
Schattauer GmbH Stuttgart

Interaction of Thrombin and Factor Xa with Bovine Vascular Endothelial Cells, Smooth Muscle Cells and Rat Hepatoma Cells

Maciej Dryjski
The Division of Clinical Pharmacology Departments of Medicine and Pharmacology, Duke University Medical Center, Durham, North Carolina, USA and the Division of Clinical Pharmacology, Department of Medicine and Department of Surgery, Jefferson Medical College, Philadelphia, Pennsylvania, USA
,
Be-Sheng Kuo
The Division of Clinical Pharmacology Departments of Medicine and Pharmacology, Duke University Medical Center, Durham, North Carolina, USA and the Division of Clinical Pharmacology, Department of Medicine and Department of Surgery, Jefferson Medical College, Philadelphia, Pennsylvania, USA
,
Thorir D Bjornsson
The Division of Clinical Pharmacology Departments of Medicine and Pharmacology, Duke University Medical Center, Durham, North Carolina, USA and the Division of Clinical Pharmacology, Department of Medicine and Department of Surgery, Jefferson Medical College, Philadelphia, Pennsylvania, USA
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Publikationsverlauf

Received 19. Mai 1987

Accepted after revision 09. Mai 1988

Publikationsdatum:
28. Juni 2018 (online)

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Summary

The aims of the present investigation were to characterize the binding and inhibition of thrombin and factor Xa to bovine vascular endothelial cells (EC), bovine smooth muscle cells (SMC), and rat hepatoma cells (RHC), and to evaluate the effects of plasma constituents on their inhibition. The enzymatic activities of bovine thrombin and factor Xa were assayed using chromogenic substrates. After 10 min incubation with the cells, thrombin activity in the solution had decreased by about 20% and was subsequently recovered on the cell surfaces. When the cells with the surface-bound thrombin were incubated with defibrinogenated plasma or antithrombin III (AT-III) for 30 sec only about 10% and 20-40%, respectively, of the initial activity could be recovered. In similar experiments with factor Xa, initial activity in the solution had decreased by 10% after 10 min incubation, and was subsequently recovered from the cell surfaces. After 30 sec incubation with AT-III, no cell surface-bound factor Xa activity was detected, whereas 10% of the bound factor Xa activity was recovered after incubation with defibrinogenated plasma. It is concluded that thrombin and factor Xa are taken up and inhibited by EC, SMC and RHC cell surfaces in similar ratios, suggesting that cell surface-mediated inhibition of clotting factors is not restricted to vascular wall cells. The inactivation of factor Xa was dependent on AT-III, however, the inactivation of thrombin was further promoted by an additional unidentified plasma constituent.