The Healing of Chronic Colonic Ulcers in the Rat

摘要

Chronic lesions of the colon and rectum were obtained by the introduction of a hydrogen peroxide solution into the rectum under pressure.Initially there was a marked mitotic response which decreased over a period of months to levels which were at the lower limits of normal. No cessation of mitotic activity was recorded. Although a relative lack of cells could have occurred in the older lesions, it is considered that this is not a factor promoting chronicity. No chronic erosions were obtained, all those examined showing evidence of re-epithelialization. Some chronic ulcers demonstrated attempted cell migration, others showed no attempt.It is suggested that a possible cause of migratory failure is a relative ischaemia of the underlying connective tissue, so that the normal interaction mechanisms between epithelial cells and the tissues of the ulcer base do not occur, leading to epithelial cell death and a subsequent failure to heal.