Vasoactive intestinal peptide is also known as the vasoactive intestinal polypeptide or VIP. In humans, it is encoded by the VIP gene. VIP is neuropeptide which belongs to a glucagon/secretin superfamily, the ligand of class II G protein-coupled receptors. VIP is produced in many tissues of vertebrates including the gut, pancreas and suprachiasmatic nuclei of the hypothalamus in the brain. VIP stimulates contractility in the heart, causes vasodilation, lowers arterial blood pressure and relaxes the smooth muscle of trachea, stomach and gall bladder. VIP has a half-life in the blood of about two minutes.