title: Enteric glial cells are associated with stress-induced colonic hyper-contraction in maternally separated rats.
abstract: BACKGROUND
  Enteric glial cells (EGCs) play important roles in enteric integrity and regulation of gastrointestinal function. However, whether EGCs undergo pathophysiological changes in stress-associated gastrointestinal disorders is unknown. We investigated structural and functional alterations in colonic EGCs and their roles in colonic contraction in an irritable bowel syndrome (IBS) model.
  
  
  METHODS
  As a chronic stress, male Wistar rats underwent 3-h maternal separation during postnatal days 2-14. As an acute stress, we used water-immersion stress (4 h) in adulthood (at 8 weeks). We quantitatively and morphologically evaluated enteric neurons and EGCs using whole-mount longitudinal muscle-myenteric plexus preparations. Colonic contraction was analyzed with electrical field stimulation (EFS).
  
  
  RESULTS
  Glial fibrillary acidic protein (GFAP) expression and the number of total, cholinergic, and nitrergic neurons were unchanged in maternally separated rats with acute stress (combined stress: an IBS model) compared with controls. However, the density of GFAP-positive EGC processes that apparently overlapped with the neurons and the extent of bulbous swelling of terminals increased according to the stress intensity: control, acute stress, maternal separation, and combined stress. EFS-induced colonic contractions were significantly greater in the combined stress rats than in controls. Higher dose of fluorocitrate, a selective inhibitor of EGC metabolism, was required to inhibit both EFS-induced contraction and EGCs activation in the combined stress rats than in controls.
  
  
  CONCLUSIONS
  Colonic EGCs exhibited structural alterations according to the stress intensity. EGCs were associated with stress-induced colonic hyper-contraction in the combined stress rats, which may underlie the pathogenesis of IBS.
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujikawa
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tominaga
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Tanaka
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tanigawa
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: Department of Gastroenterology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Arakawa
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D059329:Cholinergic Neurons / Q000378:metabolism; D003106:Colon / Q000378:metabolism* / Q000503:physiopathology; D005769:Gastrointestinal Motility / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D008297:Male; D008426:Maternal Deprivation; D009197:Myenteric Plexus / Q000378:metabolism* / Q000503:physiopathology; D009457:Neuroglia / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013315:Stress, Psychological / Q000378:metabolism* / Q000503:physiopathology
chemical_list: D005904:Glial Fibrillary Acidic Protein; D009569:Nitric Oxide; D000109:Acetylcholine
keywords: functional gastrointestinal disorders; glial cells; irritable bowel syndrome; maternal separation; stress