THE CHARACTERIZATION OF A RABBIT MODEL OF INFLAMMATORY BOWEL-DISEASE

The absence of a simple, clinically relevant, animal model of inflamma tory: bowel disease (IBD) hampers research into this disease. In this study, colitis was induced in rabbits by intracolonic installation of 2,4,6-trinitrobenzene sulphonic acid (TNB) in 25% ethanol. Rabbits wer e killed from zero hours to 6 weeks and their colons examined. Rabbits were examined by endoscopy at weekly intervals. A single dose of TNB in ethanol produced dose dependent inflammation and ulceration, which at its optimum (40 mg) resulted in cobblestoning, strictures, and bowe l wall thickening. The damage score at endoscopy was consistent with t he score on macroscopic examination of the colon. Histopathological fe atures of inflammation and ulceration observed in all animals that rec eived 40 mg TNB included crypt abscesses, ulceration, crypt architectu ral distortion and, occasionally, granulomas and pseudopolyps. These c hanges, which are similar to those observed in IBD, persisted for 6 we eks. No lasting abnormalities were observed in control animals treated with TNB in saline, with ethanol alone, or with saline only. Histopat hological similarity and the prolonged duration of inflammation, compa red to other models, make this a suitable model for investigating infl ammation in the colon. Furthermore, the model is accessible to endosco py which adds to its value in experimental studies.