Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide belonging to the vasoactive intestinal polypeptide/glucagon/ secretin family. It is widely distributed in the body, and a variety of biological actions have been reported. Recent studies have shown that there is a family of PACAP receptors (PACAPRs), and two members of this family have been identified. This is a receptor for PACAP-27 and PACAP-38. The activity of this receptor is mediated by G proteins which activate adenylyl cyclase. May regulate the release of adrenocorticotropin, luteinizing hormone, growth hormone, prolactin, epinephrine, and catecholamine. May play a role in spermatogenesis and sperm motility. Causes smooth muscle relaxation and secretion in the gastrointestinal tract (By similarity). Belongs to the G-protein coupled receptor 2 family.