Fluid Flow Stimulates Tissue Plasminogen Activator Secretion by Cultured Human Endothelial Cells

Wall shear stress generated by blood flow may regulate the expression of fibrinolytic proteins by endothelial cells. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor, type 1 (PAI-1) secretion by cultured human endothelial cells were not affected by exposure to venous shear stress (4 dynes/cm 2 ). However, at arterial shear stresses of 15 and 25 dynes/cm 2 , the tPA secretion rate was 2.1 and 3.0 times greater, respectively, than the basal tPA secretion rate. PAI-1 secretion was unaffected by shear stress over the entire physiological range.