title: Effect of nitrergic system on colonic motility in a rat model of irritable bowel syndrome.
abstract: OBJECTIVE
  The aim of this study is to investigate whether nitric oxide (NO)-mediated colonic motility was altered in rat irritable bowel syndrome (IBS) model, using different isoforms of NO-synthase (NOS) inhibitors.
  
  
  METHODS
  The animal model of IBS-like visceral hypersensitivity was induced by intra-colonic infusion of 0.5% acetic acid (AA) in saline once daily from postnatal days 8 to 21. Control animals received saline instead of AA. Experiments were performed at the end of 8 weeks. Distal colon tissues were resected and direct effects of different NOS inhibitors; N-omega-nitro-L-arginine methyl ester hydrochloride, (L-NAME), ARL-17477 dihydrochloride hydrate (ARL 17477), N-[3-(Aminomethyl) phenyl] methyl]-ethanimidamidedihydrochloride (1400 W), and N5-(1-Iminoethyl)-L-ornithine dihydrochloride (L-NIO) were evaluated concentration-dependentlyin vitrotissue bath. Besides, morphology of both groups was assessed with hematoxylin and eosin (H and E) staining and the impact of NO antibodies was determined using the immunohistochemical method.
  
  
  RESULTS
  The mean pressure values of spontaneous contractions and KCL (80 mmol/L) responses of distal colonic segments were similar in normal and IBS rats. L-NAME and ARL-17477 significantly increased the mean pressure of spontaneous colonic contractions in normal rats versus own base values (P< 0.05), but this increase did not significantly different when compared to IBS rats. In H and E staining, there was no difference with regard to morphology between two groups. Neuronal NOS (nNOS) immunoreactivity was found to be significantly decreased in IBS when compared to control groups (P< 0.05).
  
  
  CONCLUSIONS
  L-NAME and ARL-17477 mediated mean pressure values were found to be slightly decreased in IBS rats. These findings may be related to a decrease in nNOS level in IBS.
authors.affiliation: Department of Pharmacology, Atatürk Education and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Tijen Kaya
authors.initials: TK
authors.lastname: Temiz
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Izmir University, 35350, Izmir, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Demir
authors.affiliation: Department of Histology and Embriyology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Simsek
authors.affiliation: Department of Pharmacology, Atatürk Education and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Yusuf Cem
authors.initials: YC
authors.lastname: Kaplan
authors.affiliation: Department of Histology and Embriyology, Ataturk Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Selen
authors.initials: S
authors.lastname: Bahceci
authors.affiliation: Department of Pharmacology, Atatürk Education and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Barıs
authors.initials: B
authors.lastname: Karadas
authors.affiliation: Department of Laboratory Animal Science, Faculty of Medicine, Dokuz Eylul University, 35340, Izmir, Turkey.
authors.forename: Aslı
authors.initials: A
authors.lastname: Celik
authors.affiliation: Department of Pediatric Surgery, Tepecik Training and Research Hospital, Faculty of Medicine, Izmir Katip Celebi University, 35640, Izmir, Turkey.
authors.forename: Gokhan
authors.initials: G
authors.lastname: Koyluoglu
mesh_terms: D000578:Amidines / Q000494:pharmacology; D000818:Animals; D003106:Colon / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D005769:Gastrointestinal Motility / Q000187:drug effects*; D007150:Immunohistochemistry; D043183:Irritable Bowel Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D017208:Rats, Wistar
chemical_list: C102136:ARL 17477; D000578:Amidines; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester
keywords: Distal colon; immunohistochemistry; irritable bowel syndrome; nitric oxide synthase