INVOLVEMENT OF ENDOTHELIAL PECAM-1 CD31 IN ANGIOGENESIS/

The adhesive interactions of endothelial tells with each other and the adhesion receptors that mediate these interactions are probably of fu ndamental importance to the process of angiogenesis, We therefore stud ied the effect of inhibiting the function of the endothelial cell-cell adhesion molecule, PECAM-1/ CD31, in rat and murine models of angioge nesis, A polyclonal antibody to human PECAM-1, which crossreacts with rat PECAM-1, was found to block in vitro tube formation by rat capilla ry endothelial cells and cytokine-induced rat corneal neovascularizati on. In mice, two monoclonal antibodies against murine PECAM-1 prevente d vessel growth into subcutaneously implanted gels supplemented with b asic fibroblast growth factor (bFGF). Taken together these findings pr ovide evidence that PECAM-1 is involved in angiogenesis and suggest th at the interactions of endothelial cell-cell adhesion molecules are im portant in the formation of new vessels.