Plasma and urinary endothelin-1 in focal segmental glomerulosclerosis

The kidney is an important site of endothelin-l (ET-1) production and is pa rticularly susceptible to ET-1 action. Infusion of ET-1 in rats induces bot h functional and morphological alterations in the kidneys. Increased plasma level of ET-1 has been reported in patients with chronic renal failure. Ho wever, there are still no reports on the plasma and urinary ET-1 levels in patients with focal segmental glomerulosclerosis (FSGS). In the present stu dy, we have measured the plasma concentration and urinary excretion rate of ET-1 in 15 patients with nephrotic syndrome due to FSGS, and observed the serial changes of plasma and urinary ET-1 in nephrotic rats with FSGS, indu ced by repeated injection with puromycin aminonucleoside (PAN). ET-1 was me asured with radioimmunoassay. The results showed that plasma ET-1 concentra tion in FSGS patients was significantly higher than in normal controls (P < 0.05), and that urinary ET-1 excretion rate was also significantly higher in FSGS patients than in normal controls (P < 0.01). In FSGS patients, the plasma and urinary ET-1 was significantly correlated (P < 0.05), and the ur inary ET-I excretion rate was significantly correlated with the amount of p roteinuria (P < 0.05) and the glomerular sclerosing score (P < 0.01). In th e ten rats with PAN-induced FSGS, serial examination showed a significant i ncrease in plasma ET-1 after 8 weeks of injections, while the urinary ET-1 excretion rate showed a biphasic increase that showed a peak after 4 to 6 w eeks. The same changes in plasma and urinary ET-I levels were not observed in control rats injected with normal saline at the same frequency. Our resu lts suggest that ET-1 may be involved in the pathogenesis of FSGS in both h umans and rats. <(c)> 2001 Wiley-Liss, Inc.