1989 Volume 31 Issue 2 Pages 371-378_1
As an experimental model of the human inflammatory bowel disease, We attempted to produce two kinds of experimental colitis in rats. One is the chemical colitis produced by the intracolonic administration of 10% acetic acid and anothes is the colitis produced by oral administration of 5% dextran sulfate sodium (MW 54, 000). The experimental colitis was followed by serial endoscopy (Olympus GIF P-3, Q-10 and GIF V-10). In the acetic acid colitis, mucosal blood flow was also measured by the hydrogen gas clearance method through the biopsy channel. In the dextran sulfate sodium colitis mainly produced in the caecum, endoscopy was performed through the chronic caecal f istura. In the normal mucosa, the submucosal vessels were clearly seen. Immediately after administration of acetic acid, coagulation of the mucus and the mucosal surface appeared, the vessels network disappeared and the mucosal edema, redness, bleeding, ulceration were seen. Subsequently these findings gradually disappeared, but the ulcers lasted more than a month. Immediately after application of acetic aicd, the mucosal blood flow remarkably decreased and then rapidly recovered. The mucosal blood flow was well correlated with the presence of mucosal edema, not correlated with the presence of mucosal ulceration. Two days after administration of dextran sulfate sodium, bloody stools appeared. One week after administration, vascular network disappeared due to the presence of mucosal edema, and multiple hemorrhagic erosion appeared in the caecum of the rat. Subsequently mucosal bleeding gradually increased and the irregular-shaped ulcers appeared. Histologically, the acetic acid colitis showed massive coagulative necrosis in the descending colon and the dextran sulfate sodium colitis showed multiple haemorrhagic erosion in the caemum. This study would be one of the useful methods for studying human inflammatory bowel disease.
