[Development of colonic lesions caused by occlusion of paracolic marginal artery and/or vein--an experimental study using the model of ischemic colitis].

Paracolic marginal artery and/or vein of rabbit descending colon were ligated at two points with a distance of 3cm each other. The animals were sacrificed 1, 4 and 7 days after the operative procedure. The colonic segment including the vessel-ligated region was removed and studied macroscopically and microscopically. The impairment of arterial blood supply was more responsible for the development of colonic lesions. Especially, ulcerative lesions occurred only in artery-ligated and both of artery and vein-ligated groups. All the lesions occurred in the vein-ligated group were those showing only edema. Three types of mucosal folds with different etiology appeared in the vessel-ligated region of the colon, i. e., longitudinal and transverse folds and those converging to the ulcerative lesion. The morphological features of colonic lesions changed gradually. In the artery-ligated group, a variety of lesions including multiple ulcers and petechiae appeared with a longer lapse of time.