ABSTRACT
This chapter begins with a brief overview of gastrointestinal mucosal transport. Neuropeptides can alter mucosal transport processing by altering absorption and/or secretion. The effects of neuropeptides on ion transport have been studied using both in vivo and in vitro techniques. The gastrointestinal tract contains nerve fibers from both extrinsic and intrinsic nerves, with neuropeptides being present in fibers from both types. Those neurons that are intrinsic to the gut will have their cell bodies located in either submucosal or myenteric ganglia, whereas extrinsic ganglia will be the location for cell bodies of extrinsic fibers. The chapter focuses on the effects of neuropeptide Y (NPY) and peptide YY (PYY) on intestinal ion transport. The effects of NPY/PYY on intestinal ion transport have been studied both in vitro and in vivo. Interactions between neuropeptides and immunocompetent cells are a fertile field considering the central role played by such cells in inflammatory bowel diseases.
