Molecular Mechanisms of Gastrointestinal Signaling

Abstract

The epithelial cells of the gastrointestinal (GI) tract communicate with each other and with cells of other organs via a complex network of highly regulated movement of ions and biomolecules. The molecules ensure regulated activity of cells, tissues, and organs of the GI system and the body as whole. The regulated movement and subsequent activities of the biomolecules released from one cell to the target are made possible by receptive substances (receptors) localized on the membrane of the target cells or intracellular organelles, or in the cytosol. This process, which is referred to as cell-to-cell communication or cellular signaling, ensures the regulated functioning of the cells and tissues of the GI system and the whole organism. This chapter is dedicated to the mechanism of cell-to-cell communication and signaling in normal and relates it to how disease develops. Basic mechanisms of GI epithelial cell signaling and gut nutrient receptor sensing (GI chemosensation) are discussed. Abbreviations 5-HT 5-hydroxytryptamine type 7TM Seven transmembrane ADAM A disintegrin and metalloproteinase protein Akt "Ak" (mouse bred) that developed thymoma ("t") AMPA Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ANP Atrial natriuretic peptide APC Adenomatous polyposis coli