DOWNSTREAM EFFECTS OF SPLANCHNIC ISCHEMIA-REPERFUSION INJURY ON RENAL-FUNCTION AND EICOSANOID RELEASE

This study examines the hypothesis that intestinal ischemia-reperfusio n (I/R) injury contributes to renal dysfunction by altered renal eicos anoid release. Anesthetized Sprague-Dawley rats underwent 60 min of sh am or superior mesenteric artery (SMA) occlusion with 60 min of reperf usion. The I/R groups received either allopurinol, pentoxifylline, 1-b enzylimidazole, or carrier before SMA occlusion. In vivo renal artery blood flow was measured by Transonic flow probes, the kidneys were the n perfused in vitro for 30 min, and the effluent was analyzed for eico sanoid release and renal function. Intestinal I/R caused a twofold inc rease in the ratio of renal release of thromboxane B-2 to prostaglandi n E-2 and to 6-ketoprostaglandin F-1 alpha compared with the sham leve l, with a corresponding 25% decrease in renal sodium and inulin cleara nce and renal blood flow Pentoxifylline or allopurinol pretreatment re stored renal eicosanoid release and renal sodium and inulin clearance to the sham level but did not alter renal blood flow. Pretreatment wit h 1-benzylimidazole restored renal function, eicosanoid release, and r enal blood flow to sham levels. These data suggest that severe intesti nal I/R contributes to the downregulation of renal function. The decre ase in renal function is due in part to toxic oxygen metabolites, whic h occur in the milieu of altered renal eicosanoid release, reflecting a decrease in vasodilator and an increase in vasoconstrictor eicosanoi ds.