Hiroshi Satoh (1), Fumihiko Sato (1), Kenji Takami (2) and Sandor Szabo (3)
(1) Pharmaceutical Research Laboratories, Pharmaceutical Research
Division, (2) Drug Safety Research Laboratories, Pharmaceutical Development
Division, Takeda Chemical Industries, Ltd., 2-17-85 Jusohonmachi, Yodogawa-ku,
Osaka 532, Japan
(3) Department of Pathology, Harvard Medical School, Boston, Massachusetts
02115, USA
Abstract: We tried to produce a new ulcerative colitis model in rats by topical administration of sulfhydryl blockers. After male SD rats were fasted for 24 hr, 100 microliter of 3% N-ethylmaleimide (NEM) or iodoacetamide (IA) was introduced into the colon via a Nelaton's catheter. Both NEM and IA caused severe diarrhea with rectal bleeding and decreased body weight for about 7 days. At autopsy, adhesions and dilatation of the colon and severe mucosal lesions were observed. Both the weight and myeloperoxidase activity of the colon increased markedly. Maximum changes were observed within 1 - 3 days followed by gradual recovery, but even on day 21, some abnormalities were still observed. The ulceration and inflammation of the colon were confirmed by histological studies. Antiinflammatory drugs such as indomethacin inhibited the inflammation of the colon by NEM, but aggravated the ulceration. These results revealed that sulfhydryl blockers instilled into the colon caused ulcerative colitis in the rat. This model may be useful in studies on the pathogenesis of ulcerative colitis and the evaluation of drugs for therapy. Furthermore, it was suggested that antiinflammatory drugs may delay the healing of colonic ulcers.
Keywords: Antiinflammatory drug, Iodoacetamide, N-Ethylmaleimide,
Sulfhydryl blocker, Ulcerative colitis model