Embryonic angiogenesis factors

The vascular system develops during embryonic development by at least two distinct processes; vasculogenesis is the development of blood vessels from in situ differentiating angioblasts and angiogenesis is the sprouting of capillaries from pre-existing vessels. The molecular mechanisms involved in the regulation of these processes are poorly understood. Endoderm-mesoderm interactions seem to play an important role in angioblast differentiation and vasculogenesis. Soluble angiogenic factors may be involved in the vascularization of some embryonic organs, e.g. kidney and brain. Angiogenic growth factors have been isolated and purified from embryonic brain and identified as acidic and basic fibroblast growth factors. More specific endothelial cell growth factors such as platelet-derived endothelial cell growth factor and vascular endothelial growth factor may also play a role in embryonic angiogenesis.