title: Serotonin receptors and their role in the pathophysiology and therapy of irritable bowel syndrome.
abstract: BACKGROUND
  Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal tract characterized by abdominal discomfort, pain and changes in bowel habits, often associated with psychological/psychiatric disorders. It has been suggested that the development of IBS may be related to the body's response to stress, which is one of the main factors that can modulate motility and visceral perception through the interaction between brain and gut (brain-gut axis). The present review will examine and discuss the role of serotonin (5-hydroxytryptamine, 5-HT) receptor subtypes in the pathophysiology and therapy of IBS.
  
  
  METHODS
  Search of the literature published in English using the PubMed database.
  
  
  RESULTS
  Several lines of evidence indicate that 5-HT and its receptor subtypes are likely to have a central role in the pathophysiology of IBS. 5-HT released from enterochromaffin cells regulates sensory, motor and secretory functions of the digestive system through the interaction with different receptor subtypes. It has been suggested that pain signals originate in intrinsic primary afferent neurons and are transmitted by extrinsic primary afferent neurons. Moreover, IBS is associated with abnormal activation of central stress circuits, which results in altered perception during visceral stimulation.
  
  
  CONCLUSIONS
  Altered 5-HT signaling in the central nervous system and in the gut contributes to hypersensitivity in IBS. The therapeutic effects of 5-HT agonists/antagonists in IBS are likely to be due also to the ability to modulate visceral nociception in the central stress circuits. Further studies are needed in order to develop an optimal treatment.
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Viale G.B. Morgagni, 85, 50134, Florence, Italy, cristina.stasi@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Stasi
authors.forename: M
authors.initials: M
authors.lastname: Bellini
authors.forename: G
authors.initials: G
authors.lastname: Bassotti
authors.forename: C
authors.initials: C
authors.lastname: Blandizzi
authors.forename: S
authors.initials: S
authors.lastname: Milani
mesh_terms: D002490:Central Nervous System / Q000502:physiology; D017615:Enteric Nervous System / Q000502:physiology*; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects / Q000502:physiology; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D011379:Prognosis; D011985:Receptors, Serotonin / Q000378:metabolism*; D012380:Role; D012702:Serotonin Antagonists / Q000627:therapeutic use*; D012720:Severity of Illness Index; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D011985:Receptors, Serotonin; D012702:Serotonin Antagonists