FYI"Oct. 15, 2003 (Baltimore) � Significant alterations in serotonin signaling exist in the gastrointestinal tracts of IBS patients that do not appear in patients without IBS, according to new research. The findings shed light on gut motility, secretion, and sensation, as well as on the clinical manifestations of IBS, said Peter Moses, MD, associate professor of medicine and director of Clinical Research in the Digestive Diseases at the University of Vermont in Burlington. He presented the findings here Monday at the 68th annual scientific meeting of the American College of Gastroenterology. "We're showing a change at the molecular level in the gut," said co-investigator Gary Mawe, PhD, professor of anatomy and neurobiology at the University of Vermont. "Our finding that key elements of serotonin signaling are changed in IBS lends credibility to the notion that IBS is not all in patients' heads, but due to altered gut biochemistry and interactions between the gut and the brain." Researchers already knew that 95% of the body's serotonin (5-HT) is located in the gut and is primarily synthesized by and stored in endocrine cells, Dr. Moses said. That led them to suspect that alterations in serotonin may contribute to abnormal conditions in the gastrointestinal tract, leading to the development of pharmacologic agents that target 5-HT receptors, he said."http://www.medscape.com/viewarticle/462973.../7002/7002/7001 /-1[/URL]