ROLE OF ENDOGENOUS ENDOTHELIN PEPTIDES IN INTESTINAL ISCHEMIA-REPERFUSION INJURY IN RATS

In this study, the effects of BQ123 tan ETA receptor antagonist), bose ntan (a nonselective ETA-ETB antagonist), and phosphoramidon tan endot helin converting enzyme inhibitor) were investigated on intestinal muc osal 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 vei n, 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 hi stopathologic examination revealed a significant reduction in tissue i njury in both BQ123 and phosphoramidon pretreated groups compared with the control group. Bosentan, on the contrary, did not decrease the in jury. The pharmacologic examination revealed a significant reduction o f PGE(2)-like activity in both BQ123 and phosphoramidon pretreated gro ups, compared with the control group, while LTC4-like activity remaine d unchanged except for an increase in the bosentan pretreated group.