Urinary endothelin-1 in patients with renal disease

The purpose of this study was to investigate the usefulness of urinary endothelin-1 (ET-1) as a marker of renal disease. We measured urinary excretion of ET-1 in 28 patients with glomerulonephritis (GN), 22 patients with chronic renal failure (CRF), 40 patients with end-stage renal disease (ESRD), and 17 healthy volunteers. There was no significant difference in 24- hour urinary ET-1 excretion among the four groups (mean ± SEM, 0.49 ± 0.22 ng in controls, 0.79 ± 0.37 ng in GN patients, 0.39 ± 0.18 ng in CRF patients, and 0.28 ± 0.11 ng in ESRD patients). The 24-hour urinary excretion of ET-1 in patients with GN or CRF showed significant correlation with the urinary excretion of sodium (r=0.27, p<0.05). The 24-hour urinary β-microglobulin (β2M) excretion in patients with CRF (18.4 ± 2.6 mg) or ESRD (9.7 ± 1.1 mg) was significantly higher than in normal control subjects (0.23 ± 0.11 mg). Serum creatinine concentration was positively correlated with the 24-hour urinary excretion of β2M in patients with GN or CRF (r=0.50, p<0.001). These findings indicate that urinary ET-1 is not as good a marker of renal disease as urinary β2M. However, it may be responsible for urinary sodium excretion in patients with GN or CRF.