Angiogenic role of orexin-A via the activation of extracellular signal-regulated kinase in endothelial cells

► Our findings provide the first evidence that orexin-A, a neuropeptide originally discovered in the hypothalamus, stimulates angiogenesis in vivo and in vitro. ► We demonstrated the presence of orexin receptors, OX1R and OX2R, on the vascular endothelial cells. ► We found that orexin-A-induced angiogenesis requires MEK/ERK-dependent signaling pathway.