ABSTRACT
Radiation-induced enteritis is a major side effect in cancer patients undergoing abdominopelvic radiotherapy. Radiation exposure produces an uncontrolled inflammatory cascade and epithelial cell loss leading to impaired epithelial barrier function. The goal of this study was to determine the effect of rebamipide on regeneration of the intestinal epithelia after radiation injury. The abdomens of C57BL/6 mice were exposed to 13Gy of irradiation (IR) and then the mice were treated with rebamipide. Upon IR, intestinal epithelia were destroyed structurally at the microscopic level and bacterial translocation was increased. The intestinal damage reached a maximum level on day 6 post-IR and intestinal regeneration occurred thereafter. We found that rebamipide significantly ameliorated radiation-induced intestinal injury. In mice treated with rebamipide after IR, intestinal barrier function recovered and expression of the tight junction components of the intestinal barrier were upregulated. Rebamipide administration reduced radiation-induced intestinal mucosal injury. The levels of proinflammatory cytokines and matrix metallopeptidase 9 (MMP9) were significantly reduced upon rebamipide administration. Intestinal cell proliferation and ß-catenin expression also increased upon rebamipide administration. These data demonstrate that rebamipide reverses impairment of the intestinal barrier by increasing intestinal cell proliferation and attenuating the inflammatory response by inhibiting MMP9 and proinflammatory cytokine expression in a murine model of radiation-induced enteritis.
Subject(s)
Alanine/analogs & derivatives , Enteritis/prevention & control , Epithelial Cells/drug effects , Intestinal Mucosa/drug effects , Quinolones/pharmacology , Radiation Injuries, Experimental/prevention & control , Radiation-Protective Agents/pharmacology , Alanine/pharmacology , Animals , Bacterial Translocation/drug effects , Bacterial Translocation/radiation effects , Cell Proliferation/drug effects , Cytokines/metabolism , Cytoprotection , Dose-Response Relationship, Drug , Enteritis/metabolism , Enteritis/pathology , Epithelial Cells/metabolism , Epithelial Cells/pathology , Epithelial Cells/radiation effects , Inflammation Mediators/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Intestinal Mucosa/radiation effects , Male , Matrix Metalloproteinase 9/metabolism , Mice, Inbred C57BL , Radiation Injuries, Experimental/metabolism , Radiation Injuries, Experimental/pathology , Tight Junctions/drug effects , Tight Junctions/metabolism , Tight Junctions/pathology , Tight Junctions/radiation effects , Time Factors , beta Catenin/metabolismABSTRACT
A 12-year-old, spayed female Schnauzer presented with constipation. A mass was observed in the pelvic cavity, and metastasis was not identified. Mass resection was performed through celiotomy with pubic osteotomy, and hemangiosarcoma was diagnosed. At 10 weeks post-operatively, the patient died of multiple metastasis. Primary intrapelvic hemangiosarcoma is rare in dogs.
