Vasoactive intestinal peptide (VIP, also polypeptide) is a kind of hormone that has 28 amino acid residues in it and is made in many areas of the human body including the gut, pancreas, and suprachiasmatic nuclei (which is a small part of the brain's midline) of the hypothalamus in the brain. In humans, the vasoactive intestinal peptide is encoded, or transforming information from one format into another, by the VIP gene.
VIP has a half-life in the blood of about two minutes.
VIP is made more than it should in a VIPoma. Increase intestinal secretion, relaxes sphincters and smooth muscles. Released from nerve cells in mucosa and smooth muscle.