Role of endogenous endothelin peptides in intestinal ischemia-reperfusion injury in rats

In this study, the effects of BQ123 tan ETA receptor antagonist), bosentan (a nonselective ETA-ETB antagonist), and phosphoramidon tan endothelin converting enzyme inhibitor) were investigated on intestinal mucosal lesion formation and changes in tissue PGE(2) and LTC4 levels due to intestinal ischemia-reperfusion (I/R) injury in rats. Following 30 min of ischemia, the substances were given via the inferior caval vein, and 10 min later the intestine was subjected to reperfusion for 30 min. The intestinal specimens were evaluated both microscopically and the tissue PGE(2) and LTC4 levels were obtained for each group. The histopathologic examination revealed a significant reduction in tissue injury in both BQ123 and phosphoramidon pretreated groups compared with the control group. Bosentan, on the contrary, did not decrease the injury. The pharmacologic examination revealed a significant reduction of PGE(2)-like activity in both BQ123 and phosphoramidon pretreated groups, compared with the control group, while LTC4-like activity remained unchanged except for an increase in the bosentan pretreated group.