Neuropeptide Y

Abstract

—Sympathetic nerves have long been suspected of trophic activity, but the nature of their angiogenic factor has not been determined. Neuropeptide Y (NPY), a sympathetic cotransmitter, is the most abundant peptide in the heart and the brain. It is released during nerve activation and ischemia and causes vasoconstriction and smooth muscle cell proliferation. Here we report the first evidence that NPY is angiogenic. At low physiological concentrations, in vitro, it promotes vessel sprouting and adhesion, migration, proliferation, and capillary tube formation by human endothelial cells. In vivo, in a murine angiogenic assay, NPY is angiogenic and is as potent as a basic fibroblast growth factor. The NPY action is specific and is mediated by Y1 and Y2 receptors. The expression of both receptors is upregulated during cell growth; however, Y2 appears to be the main NPY angiogenic receptor. Its upregulation parallels the NPY-induced capillary tube formation on reconstituted basement membrane (Matrigel); t...