| Popis: |
This chapter focuses on pituitary adenylate cyclase activating polypeptide (PACAP). PACAP is expressed in the enteric nervous system of the gastrointestinal tract, where it functions to increase secretory activity and motility. PACAP is as a key regulator in gastric acid secretion. Receptors for PACAP (PAC1) are expressed on the enterochromaffinlike (ECL) cells of the gastric corpus, where they regulate the release of histamine. PACAP is expressed in both gastric and colonic neurons, where it regulates gastrointestinal physiology. PACAP has also been demonstrated to regulate immune function in the GI tract and may be a key regulator of the inflammatory response associated with conditions such as inflammatory bowel disease. Receptors for PACAP have been discovered on tumors of the GI tract, and their stimulation is involved with growth of colonic tumors. PACAP has been specifically linked to some human motility disorders such as Hirschsprung's disease, in which there is a reduction in PACAP-immunoreactive nerve fibers. © 2006 Elsevier Inc. All rights reserved. |
