MODULATION OF ENDOTHELIUM BY HEPARIN AND RELATED POLYELECTROLYTES

The vascular endothelium is an important mediator of the hemostatic ba lance. In addition to shielding subendothelial tissue factor from flow ing blood, endothelial cells produce a number of substances which favo r an antithrombotic state including TFPI and tPA. The ability of polye lectrolytes such as heparin and defibrotide to modulate endothelial fu nction is examined using animal models and human studies. Like heparin , defibrotide is observed to increase plasma TFPI antigen levels. Addi tionally, defibrotide administration is observed to increase plasma tP a antigen levels and to decrease PAI, TF and endothelin levels. Modula tion of endothelial function by defibrotide may account for its benefi cial effect in PAOD.