ENDOTHELIN-1 IN ACUTE-RENAL-FAILURE

To study the pathological significance of circulating endothelin (ET) in ARF; we measured plasma ET in seven children (mean age 8.8 +/- 4.4 years) with ARF in the most severe phase and 3.7 +/- 3.5 months later in the recovery period. Twenty-seven healthy children were included in the study as controls. Plasma ET level was measured by highly sensiti ve and specific radioimmunoassay for ET-1 and ET-2 (ET-1/2, Biomedica, Vienna). Plasma ET was significantly higher in the most severe phase of ARF (4.75 +/- 4.08 fM/ml) than in the recovery period (0.78 +/- 0.2 4 fM/ml; p < 0.01), but comparing to plasma ET in the healthy children , the difference was only of borderline statistical significance (Pf, 0.0573). Since plasma concentrations of creatinine did not correlate w ith plasma ET in patients, either in acute or in the recovery phase of disease, we concluded that decreased GFR is not the main factor deter mining an increased ET in ARF. We suggest that elevated plasma ET in A RF may be secondary to vascular endothelial dysfunction and speculate that enchancement synthesis of endothelial relaxing factor (EDRF) inhi bits ET synthesis during the recovery period. We did not find any rela tionship between plasma ET and blood pressure (BP) in patients with AR F; so we conclude that circulating ET is not the main factor determini ng BP in ARF.