Platelet-activating factor directly stimulates in vitro migration of endothelial cells and promotes in vivo angiogenesis by a heparin-dependent mechanism.

The aim of the present study was to investigate the angiogenic properties of platelet-activating factor (PAF). In vitro PAF was shown to induce a dose-dependent migration of human endothelial cells (EC) across the polycarbonate filters in Boyden's chambers. In contrast, D-PAF, the biologically inactive enantiomer, and Lyso-PAF did not stimulate a significant migration of EC.