Influence of cardiovascular damage and residual renal function on plasma endothelin in chronic renal failure

To study the influence of cardiovascular damage on plasma endothelin in chronic renal failure, we have measured the plasma concentration of this peptide in 32 uremic patients (7 undialyzed uremics, 8 CAPD patients and 16 hemodialysis patients) and in 9 healthy subjects. Sixteen patients had severe cardiovascular damage while the other 16 had no cardiovascular involvement. Endothelin was markedly raised (p < 0.01) in the uremic group as a whole (13.9 +/- 2.6 pmol/l) in comparison with the group of healthy subjects (8.6 +/- 1.6 pmol/l). Hemodialysis patients displayed endothelin levels much higher (p < 0.01) than CAPD patients and undialyzed uremics. Endothelin was directely related with BUN (r = 0.37) and with serum creatinine (r = 0.52) in dialysis patients. Similar correlations were also found in undialyzed uremics. Plasma endothelin was almost identical in patients with severe cardiovascular damage (15.5 +/- 1.6 pmol/l) and in those without cardiovascular involvement (15.9 +/- 2.6 pmol/l). There was no relationship between arterial pressure and plasma endothelin. Residual renal function is an important determinant of circulating endothelin even at very advanced stages of renal insufficiency. It appears unlikely that atherosclerosis plays a major role in the pathogenesis of high plasma concentration of this peptide in uremic patients.