Neuropeptide Y: Sympathetic Cotransmitter and Modulator?

Abstract

Neuropeptide Y (NPY) exerts potent vasoconstrictor activity and is coreleased with noradrenaline from sympathetic nerves, mainly on a high degree of activation. It may contribute to the vasoconstriction on high-frequency sympathetic stimulation during control conditions and mediate the long-lasting responses evoked by nerve stimulation in the absence of noradrenaline. NPY enhances the vasomotor effects to noradrenaline and inhibits its release from perivascular nerves. NPY probably is a cotransmitter in sympathetic vascular control.