title: An experimental model of colitis induced by dextran sulfate sodium from acute progresses to chronicity in C57BL/6: correlation between conditions of mice and the environment.
abstract: OBJECTIVE
  To induce acute colitis progresses to chronicity in C57BL/6 mice by dextran sulfate sodium.
  
  
  BACKGROUND
  Murine models are essential tools to understand IBD pathogenesis. Among different types of chemically induced colitis models, the dextran sulfate sodium (DSS)-induced colitis model is the most common model of IBD, due to its simplicity.
  
  
  METHODS
  Male C57BL/6 mice 6-8 weeks old, were collected and matched by age with controls. C57BL/6 mice treated with 2 cycles of 3.5% DSS for 4 days and 4 days of pure water between each cycle. After that, mice were sacrificed and the entire colon was removed. Small sections of the colon were fixed in formaldehyde, embedded in paraffin and sectioned with a microtome. Sections were stained with hematoxylin eosin to analyses the degree of inflammation.
  
  
  RESULTS
  After the first cycle oral administration of DSS, mice with severe and visible rectal bleeding and diarrhea entered into the acute phase. After day 4-5, bleeding and diarrhea were improved and mice entered into the chronic phase with peak levels of weight loss. Macroscopically, the inflammation was predominantly located in the distal colon. Microscopically, examination of the distal colon sections showed a decrease number of goblet cells, loss of crypts, signs of surface epithelial regeneration and moderate to severe infiltration of inflammatory cells in the mucosa.
  
  
  CONCLUSIONS
  In order to achieve an experimental colitis model, our protocol is recommended for future therapies in IBD experimental modeling.
authors.affiliation: Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Niloofar
authors.initials: N
authors.lastname: Taghipour
authors.affiliation: Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahsa
authors.initials: M
authors.lastname: Molaei
authors.affiliation: Immunology Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Nariman
authors.initials: N
authors.lastname: Mosaffa
authors.affiliation: Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Rostami-Nejad
authors.affiliation: Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Asadzadeh Aghdaei
authors.affiliation: Department of veterinary, College of Agriculture, Islamic Azad University, Abhar branch, Abhar, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Anissian
authors.affiliation: Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Pedram
authors.initials: P
authors.lastname: Azimzadeh
authors.affiliation: Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Zali
keywords: C57BL/6; DSS; Inflammatory bowel disease; Murine models