title: The Effect of the iNOS Inhibitor S-Methylisothiourea and Hyperbaric Oxygen Treatment on Radiation Colitis in Rats.
abstract: BACKGROUND
  External radiotherapy is one of the main treatment modalities for a variety of malignancies. However, the lower gastrointestinal tract is sensitive to the ionizing radiation. Hyperbaric oxygen treatment (HOT) has been suggested as a viable treatment for refractory radiation colitis, but the effect of S-Methylisothiourea (SMT) in the radiation colitis have not reported. To investigate the effect of SMT, HOT and the combination of both in an acute radiation-induced enterocolitis model.
  
  
  METHODS
  Sixty Sprague-Dawley rats were divided randomly into five equal groups. A single dose of gamma irradiation (25 Gy) was administered through the colorectal region to anesthetized rats. In the control group, we applied 2 ml of saline solution intraperitoneally for five days. In the HOT group, 100-per-cent oxygen at 2.5 atm pressure was applied for five days. In the SMT group, 10 mg/kg/day of SMT was applied intraperitoneally for five days. In the HOT+SMT group, HOT and SMT were both applied in the same dosages as in the preceding two groups. At the end of five days, the rats were sacrificed and colon samples were collected for histological grading. Blood samples were collected to test for : tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), IL-1β, transforming growth factor-β (TGF-β) and intercellular adhesion molecule-1 (ICAM-1) mRNA.
  
  
  RESULTS
  The TNF-α, IL-1β, IL-10 and TGF-β levels were reduced by SMT, HOT and HOT+SMT applications (p < 0.05). However ICAM-1 mRNA levels were not significantly lower (p:0.19). The microscopic scores differed significantly between the SMT, HOT and HOT+SMT groups and the control group. There was significant improvement histologically, especially in the HOT+SMT group. When we compared the weight of the rats before and after the study, weight loss was significantly lower in the SMT, HOT and HOT+SMT groups compared with the control group (p < 0.05).
  
  
  CONCLUSIONS
  HOT and SMT together were significantly more effective in preventing weight loss and in reducing inflammation and the severity of colitis histology when compared with HOT and SMT separately.
authors: H
authors: H
authors: Demirci
authors: Z
authors: Z
authors: Polat
authors: A
authors: A
authors: Uygun
authors: A
authors: A
authors: Kadayifci
authors: O
authors: O
authors: Sager
authors: K
authors: K
authors: Oztutk
authors: F
authors: F
authors: Sahiner
authors: B
authors: B
authors: Caliskan
authors: Y
authors: Y
authors: Karslioglu
authors: M
authors: M
authors: Ozler
authors: M
authors: M
authors: Ozel
authors: H
authors: H
authors: Ergun
authors: O
authors: O
authors: Ozturk
authors: M
authors: M
authors: Beyzadeoglu
authors: S
authors: S
authors: Bagci
mesh_terms: D000818:Animals; D003092:Colitis / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D003106:Colon / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006931:Hyperbaric Oxygenation; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D053583:Interleukin-1beta / Q000187:drug effects / Q000276:immunology; D007550:Isothiuronium / Q000031:analogs & derivatives* / Q000494:pharmacology; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors*; D011833:Radiation Injuries, Experimental / Q000276:immunology / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects / Q000276:immunology
chemical_list: D004791:Enzyme Inhibitors; C000594089:IL1B protein, rat; D053583:Interleukin-1beta; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D016753:Interleukin-10; D007550:Isothiuronium; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; C027744:S-methylisothiopseudouronium