Acute renal failure in rats. Interaction between a contrast medium and renal arterial occlusion

Acute renal failure is a serious complication of reconstructive aortoiliac surgery. The question was raised whether its etiology includes interaction between preoperative angiographic contrast medium and intra-operative clamping of the renal arteries. Renal arteries of 180 rats were bilaterally clamped 10 to 120 min and serum urea was determined from 3 h to 7 days later. In 35 rats 40 min clamping alone produced an increase in urea reaching a maximum 1 day later (median increase 70%). In 3 groups of 12 rats intravenous injection of the contrast medium metrizoate alone in doses 1, 2 and 3 g I/kg body-weight produced no significant increase in urea. Intravenous injection of the same doses to 3 groups of 10 rats each followed 1 h later by renal arterial occlusion for 40 min produced median urea increases one day later of 110, 130 and 170 per cent, respectively, in the 3 groups. The increase was higher than that produced by contrast medium alone (p less than 0.01) or by renal artery clamping alone (p less than 0.05) indicating a potentiation of transient renal failure by the combination of contrast medium and renal arterial clamping.