Pathophysiological role of endothelin in renal transplantation

To assess the pathophysiological role of endothelin (ET) in the early post-transplantation period, we followed plasma ET concentrations for 2 months from 1 week prior to surgery in four renal transplant patients. Plasma ET concentrations were elevated before transplantation in all patients. In two patients who developed marked pretibial edema, plasma ET concentrations increased before the onset of edema and before the increase in plasma atrial natriuretic peptide (ANP) concentrations, and remained high while the edema persisted. In the other two patients without edema, plasma ET and ANP concentrations fell toward normal immediately after transplantation. Plasma ET concentration increased transiently again in one of these patients when acute rejection occurred. After recovery from this rejection episode, the plasma ET concentration again fell to the normal range. There were significant correlations between plasma ET concentrations and changes in body weight and urine volume. These results suggest that the plasma ET concentration may reflect the function of transplanted kidneys and that ET may modulate body fluid volume regulation after transplantation. In addition, ET may participate in the pathogenesis of acute rejection.