Neuropeptide Y (NPY) is a peptide abundantly distributed throughout the central and peripheral nervous system that plays a major role in controlling appetite, blood pressure, cardiac contractility, and intestinal secretion. Five subtypes of the NPY receptor have been identified. Subtypes Y1 and Y5 have known roles in the stimulation of feeding while Y2 and Y4 seem to have roles in satiety. NPY has also been shown to interact with the immune system, promoting gastrointestinal inflammation, as well as exhibiting an antimicrobial effect against several gut bacteria.
