The role of endothelin in early renal cortical reperfusion in renal transplantation

The role of specific endothelin receptors in the early renal reperfusion and long-term survival in renal transplantation was investigated in Lewis rats. Left renal transplantation was performed following 2 h cold ischaemia without and with ET_A receptor antagonism and following 16 h cold ischaemia with no treatment, with ET_A receptor antagonism and with ET_B receptor antagonism. The ET_A and ET_B receptor antagonists, BQ-610 and A-192621 respectively, were added to the preservation solution. Renal cortical perfusion (RCP) was measured postoperatively using laser Doppler flowmetry. All rats in the 2-hour groups survived for 15 days. Animals in the untreated 16-hour group or in the A-192621-treated group died between days 3 and 6 after surgery. Fifty percent of the rats in the 16-hour and BQ-610-treated group died between days 4 and 7 after surgery while the other 50% survived for 15 days. Survival rates correlated well with both the postoperative serum creatinine and the recovery of RCP. We conclude that addition of an ET_A receptor antagonist to the preservation solution improves renal reperfusion and long-term survival following prolonged ischaemia, whereas ET_B receptor antagonism does neither.