title: Inflammatory bowel disease in rats: bacterial and chemical interaction.
abstract: OBJECTIVE
  To develop a novel model of colitis in rats, using a combination of iodoacetamide and enteropathogenic E. coli (EPEC), and to elucidate the pathophysiologic processes implicated in the development of ulcerative colitis (UC).
  
  
  METHODS
  Male Sprague-Dawley rats (n = 158) were inoculated intrarectally on a weekly basis with 4 different combinations: (a) 1% methylcellulose (MC), (b) 100 microL of 6% iodoacetamide (IA) in 1% MC, (c) 200 microL containing 4 x 10(8) colony factor units (CFU) of EPEC, and (d) combined treatment of (IA) followed by bacteria (B) after 2 d. Thirty days post treatment, each of the four groups was divided into two subgroups; the inoculation was stopped for one subgroup and the other subgroup continued with biweekly inoculation until the end of the experiment. Colitis was evaluated by the clinical course of the disease, the macroscopic and microscopic alterations, activity of myeloperoxidase (MPO), and by TNF-alpha gene expression.
  
  
  RESULTS
  Findings indicative of UC were seen in the combined treatment (IA + B) as well as the IA continued treatment groups: the animals showed slow rate of increase in body weight, diarrhea, bloody stools, high colonic ulcer score, as well as histological alterations characteristic of UC, with an extensive inflammatory reaction. During the course of the experiment, the MPO activity was consistently elevated and the TNF-alpha gene expression was upregulated compared to the control animals.
  
  
  CONCLUSIONS
  The experimental ulcerative colitis model used in the present study resembles, to a great extent, the human disease. It is reproducible with characteristics indicative of chronicity.
authors.affiliation: Faculty of Medicine, 110236/41 Riad El-Slaleh, 1107-2020 American University of Beirut, Beirut, Lebanon.
authors.forename: Inaya-Abdallah
authors.initials: IA
authors.lastname: Hajj Hussein
authors.forename: Rania
authors.initials: R
authors.lastname: Tohme
authors.forename: Kassem
authors.initials: K
authors.lastname: Barada
authors.forename: Mostafa Hassan
authors.initials: MH
authors.lastname: Mostafa
authors.forename: Jean-Noel
authors.initials: JN
authors.lastname: Freund
authors.forename: Rosalyn A
authors.initials: RA
authors.lastname: Jurjus
authors.forename: Walid
authors.initials: W
authors.lastname: Karam
authors.forename: Abdo
authors.initials: A
authors.lastname: Jurjus
mesh_terms: D000818:Animals; D003093:Colitis, Ulcerative / Q000139:chemically induced* / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D044683:Colon, Descending / Q000187:drug effects* / Q000201:enzymology / Q000382:microbiology* / Q000473:pathology; D004195:Disease Models, Animal; D054308:Enteropathogenic Escherichia coli; D007460:Iodoacetamide; D008297:Male; D009195:Peroxidase / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009195:Peroxidase; D007460:Iodoacetamide