title: Alterations of colonic contractility in an interleukin-10 knockout mouse model of inflammatory bowel disease.
abstract: OBJECTIVE
  Inflammatory bowel disease is commonly accompanied by colonic dysmotility and causes changes in intestinal smooth muscle contractility. In this study, colonic smooth muscle contractility in a chronic inflammatory condition was investigated using smooth muscle tissues prepared from interleukin-10 knockout (IL-10(-/-)) mice.
  
  
  METHODS
  Prepared smooth muscle sections were placed in an organ bath system. Cholinergic and nitrergic neuronal responses were observed using carbachol and electrical field stimulation with L-NG-nitroarginine methyl ester (L-NAME). The expression of interstitial cells of Cajal (ICC) networks, muscarinic receptors, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) was observed via immunofluorescent staining.
  
  
  RESULTS
  The spontaneous contractility and expression of ICC networks in the proximal and distal colon was significantly decreased in IL-10(-/-) mice compared to IL-10(+/+) mice. The contractility in response to carbachol was significantly decreased in the proximal colon of IL-10(-/-) mice compared to IL-10(+/+) mice, but no significant difference was found in the distal colon. In addition, the expression of muscarinic receptor type 2 was reduced in the proximal colon of IL-10(-/-) mice. The nictric oxide-mediated relaxation after electrical field stimulation was significantly decreased in the proximal and distal colon of IL-10(-/-) mice. In inflamed colon, the expression of nNOS decreased, whereas the expression of iNOS increased.
  
  
  CONCLUSIONS
  These results suggest that damage to the ICC network and NOS system in the proximal and distal colon, as well as damage to the smooth muscle cholinergic receptor in the proximal colon may play an important role in the dysmotility of the inflamed colon.
authors.affiliation: Department of Physiology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Catholic University of Daegu School of Medicine, Daegu, Korea.
authors.forename: Joong Goo
authors.initials: JG
authors.lastname: Kwon
authors.affiliation: Department of Physiology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Sun Joo
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Physiology, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Dae Kyu
authors.initials: DK
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Seok Guen
authors.initials: SG
authors.lastname: Lee
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Eun Su
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Kwang Bum
authors.initials: KB
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Byung Ik
authors.initials: BI
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Dae Hwan
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Kangwon National University School of Medicine, Chuncheon, Korea.
authors.forename: Jeong-Im
authors.initials: JI
authors.lastname: Sin
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea.
authors.forename: Tae Wan
authors.initials: TW
authors.lastname: Kim
authors.affiliation: Department of Anatomy, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: In Hwan
authors.initials: IH
authors.lastname: Song
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Park
keywords: Colon; Contractility; Inflammatory bowel diseases; Interleukin-10