Antithrombin III, the major modulator of intravascular coagulation, is synthesized by human endothelial cells

Thromb Haemost. 1981 Aug 28;46(2):504-6.

Abstract

Human endothelial cells in culture is shown to synthesize antithrombin III (At-III). The endothelial cell At-III (EC-At-III) consists of a small fraction similar to plasma At-III and a larger fraction with decreased heparin-binding as tested by crossed immunoelectrophoresis. However, both the anti-Xa and thrombin-neutralizing activities of the EC-At-III were rapid and active even in the absence of added heparin. It is concluded that the major portion was probably bound to endogenous heparin-like substance, thus accounting for its decreased exogenous heparin binding. The presence of At-III and other antithrombotic factors in the vascular endothelium offer protection against thrombosis and possibly atherosclerosis.

MeSH terms

  • Antithrombin III / biosynthesis*
  • Antithrombin III / pharmacology
  • Autoradiography
  • Blood Vessels / cytology
  • Blood Vessels / metabolism*
  • Cells, Cultured
  • Endothelium / metabolism
  • Factor X / antagonists & inhibitors
  • Factor Xa
  • Heparin / pharmacology
  • Humans
  • Immunoelectrophoresis, Two-Dimensional
  • Neutralization Tests
  • Thrombin / antagonists & inhibitors

Substances

  • Antithrombin III
  • Factor X
  • Heparin
  • Thrombin
  • Factor Xa