A 36-amino acid neuropeptide that is widespread throughout the animal kingdom and in various body systems and has key roles in energy metabolism and in regulating the activity of the heart and blood vessels. It is a potent stimulant of appetite, being released from cells in the hypothalamus, where it activates NPY receptors, which are G-protein-coupled receptors. It also regulates secretion of gonadotrophin-releasing hormone from the hypothalamus. Its release is triggered by the gut hormone ghrelin and inhibited by the hormone leptin. NPY is widely distributed in the brain and sympathetic nervous system and commonly occurs in nerve cells that secrete the neurotransmitter noradrenaline. In general it modulates the effects of adrenaline and noradrenaline, for example by decreasing contraction of heart muscle and reducing blood flow through coronary vessels. It is also significant in the reduction of anxiety and control of blood pressure.
Subjects: Chemistry — Biological Sciences.