Receptors and ligands role in colon physiology and pathology.

Colonic diseases are more prevalent during the past decade. Colorectal cancer, ulcerative colitis, Crohn's disease, diverticulitis, irritable bowel syndrome are the major reported colonic diseases. Innovative strategies are defensible in order to advance the efficacy of colonic disease treatment. During the past decade there has been an extensive advance in the understanding of receptor signaling both from a clinical as well as a preclinical perspective. A sound knowledge on molecular pathways that characterize cell growth, cell cycle, apoptosis, angiogenesis and invasion has provided novel targets in colorectal cancer therapy and inflammatory pathways in the ulcerative colitis. Receptor signaling has been involved in these pathways. To understand the receptor ligand interaction, one must have the basic knowledge regarding those receptors and ligands. This review summarizes the existing knowledge of the expression and function of various receptors and ligands in the colonic tissue. It also covers their role in the physiological processes and pathological conditions of colon.