Plasma concentration of uroguanylin in patients on maintenance dialysis therapy

Background: Uroguanylin, originally isolated from urine, is a new natriuret ic peptide. Its plasma level is increased in association with renal impairm ent and fluid retention in patients with renal diseases. Methods: Uroguanyl in concentrations were measured in patients on hemodialysis (HD, n = 76) an d those on continuous ambulatory peritoneal dialysis (CAPD, n = 10) using a sensitive radioimmunoassay for human uroguanylin, Results: Plasma concentr ations of immunoreactive (ir)-uroguanylin in the patients on HD and CAPD (2 12.0 +/- 17.4 and 245.3 +/- 39.5 fmol/ml) were significantly higher than th e value for the normal controls (5.0 +/- 0.3 fmol/ml). Plasma ir-uroguanyli n levels before the start of regular HD were correlated with predialysis ex cess weight based on their dry weights (r = 0.33, p < 0.01) and with dialys is duration (r = 0.26, p < 0.05), The plasma levels in patients with HD, fo r whom high-flux membranes were used, were decreased at the end of regular HD as compared with the prior levels (p < 0.05), but not in those who under went HD with conventional membranes. Conclusion: These findings suggest tha t the plasma ir-uroguanylin level is related to the patient's volume status as well as renal impairment. Whether the accumulation of uroguanylin has a pathological effect has yet to be determined. Copyright (C) 2000 S. Karger AG, Basel.