Neuropeptide Y and the autonomic nervous system

Neuropeptide Y (NPY) is a neuromodulator and co-transmitter widely expressed throughout the autonomic nervous system. It is predominantly located in sympathetic neurons supplying the vasculature and heart. It is also located in parasympathetic neurons and enteric neurons and released from platelets. NPY has a diverse range of physiological functions and plays a key role in the regulation of intestinal absorption, and neuromodulation of classical neurotransmitters. It is implicated in the pathogenesis of cardiovascular disease, in particular vasoconstriction, arrhythmia, angiogenesis, and cardiac remodeling. Elevated plasma levels of NPY are found in hypertension, myocardial infarction, and heart failure. There is growing support for the idea that the neuropeptide itself may play a detrimental role via Y1 receptor signaling, but that NPY fragments targeting other receptors may be beneficial. This chapter will focus on the structure and normal physiological function of NPY, followed by a discussion of its growing role in disease pathogenesis.