The G protein-coupled receptor superfamily includes several subtypes of neuropeptide Y receptors. The terms Y1, Y2, Y4, Y5, and Y6 refer to the five cloned NPY receptor subtypes in mammals. Vasoconstriction and feeding are two physiological responses that are mediated by neuropeptide Y receptors.
Humans express the Y1, Y2, Y4, and Y5 subtypes. They are primarily found in tissues like the cardiovascular system and the central and peripheral nervous systems. The neurotransmitter Neuropeptide Y, as well as the hormones peptide YY (PYY) and pancreatic polypeptide (PP), are their physiological ligands.
Important biological and pathophysiological processes like blood pressure, neuroendocrine secretions, seizures, neuronal excitability, and neuroplasticity are regulated by neuropeptide Y and its receptors.