Rapid intestinal ischaemia-reperfusion injury is suppressed in genetically mast cell-deficient Ws/Ws rats

Ws/Ws rats have a small deletion of the c-kit gene, and are deficient in both mucosal and connective tissue-type mast cells. In this study, the role of mucosal type mast cells (MMC) in the development of intestinal ischaemia-reperfusion injury was investigated in Ws/Ws rats. Autoperfused segments of the jejunum were exposed to 60 min of ischaemia, followed by reperfusion for various time periods. The epithelial permeability was then assessed by the 51Cr-EDTA clearance rate. In the control (+/+) rats, the maximal increase in mucosal permeability was achieved at 45 min of reperfusion. In contrast, this increase was significantly and potently attenuated in the Ws/Ws rats. Mucosal alkaline phosphatase activity decreased in the control (+/+) rats, but was not altered in the Ws/Ws rats. There were no differences in mucosal myeloperoxidase activity, indicating that granulocytes did not contribute to tissue injury. These results provide direct evidence for the role of mast cells in the pathogenesis of intestinal ischaemia-reperfusion injury.