The significance of ischemia for the proliferative activity of the mucosa in inflammatory bowel diseases

Abstract

The state of the microcirculatory bed remains one of the determining factors in course of inflammatory bowel diseases (IBD). The presence of small foci of ischemia could realize in dystrophic-necrobiotic consequences, which can also underlie the development or strengthening of the inflammatory process. Based on above, the goal of our study was to determine the impact of the development of mucosal ischemia in the colon on the activity of proliferative processes during inflammation. Materials and methods. The study was performed on 12 adult WAG rats with modeling IBD by oral administration of 2.5% solution Dextran Sulfate Sodium. Serial slides of the colon where made with stained with hematoxylin and eosin, according to Rego, immunohistochemical examination (IHC) to Ki67. Volume of ischemic area and Ki67 expression were detected. Statistical comparison was performed. Results. Inspection microscopy in the DSS experimental group determined alterative-desquamative changes in the surface epithelium and epithelium of intestinal glands (crypt); diffuse polymorphic cellular infiltration in the mucous membrane, which in some places spread to the submucosal base, that are morphological manifestations of IBD. Foci of ischemia had been detected in that group with 13.09±0.67% volume as just microfocal changes were observed in intact animals (p < 0.05). Detection of proliferative activity depending on ischemic signs was realized in different level of Ki67 expression. So, lowest level of Ki67 was estimated in mucosa above ischemia (18.06±3.33%). Most pronounced expression of Ki67 was observed in IBD group in area which no connected with ischemia and was even 57.71±4.68% (p < 0.05). Conclusions. Ki67 was strongly expressed in epithelial cells of the colon both in intact tissue and in modeling IBD with significant increasing expression more than twice in inflammatory group (p < 0.05) but spreading of activity process was uneven. Collation of slides with ICH and Rego staining realized in estimation of strong negative correlation between Ki67 expression and ischemia (r=-0.819).