An Experimental Study of the Pathogenesis of The Ischemic Colitis

Abstract

The purpose of this study is investigation for the pathogenesis of the ischemic colitis in rats.
An experimental model of ischemic colitis was designed in 140 rats by ligation of the mesenteric vessels in the colon and closure in the anal canal. The effects on blood flow in the colonic wall with mesenteric vascular ligation and with increasing the intraluminal pressure by colonic distension were studied with hydrogen clearance method. Histological examinations for ischemic lesion were undertaken in sacrified rats.
The results were as follows : 1) The incidence of ischemic ulcer was higher in the group of ligation of the mesenteric vessels in the colon and closure in the anal canal simultaneously than in the group of the vascular ligation or the anal closure alone. In the group of which anals were closed at 6 hours after ligation of the mesenteric vessels the incidence was decreased markedly. 2) The colonic blood flow at 1.5 hours after mesenteric vascular ligation fell remarkably and recovered rapidly. The blood flow was significantly diminished by an intraluminal pressure of over 10 mmHg. 3) Various ischemic changes of the colon similar to human ischemic colitis could be produced in rats by ligation of the mesenteric vessels and/or closure of the anal canal. 4) These results seemed to suggest that in the pathogenesis of the ischemic colitis an important role be played by relationship between intraluminal pressure and colonic blood flow.