Plasma and urine levels of adrenomedullin and proadrenomedullin N-terminal 20 peptide in chronic glomerulonephritis.

Proadrenomedullin N-terminal 20 peptide (PAMP) is a novel hypotensive peptide present in the precursor of adrenomedullin (AM), a vasodilative and natriuretic peptide. We examined the plasma and urinary levels of these peptides in patients with chronic glomerulonephritis (CGN). The mean plasma AM concentration of the patients with CGN did not differ from that of control subjects (4.17 +/- 0.17 v 3.87 +/- 0.21 fmol/mL, respectively), whereas urinary AM excretion was significantly less in the patients with CGN (5.96 +/- 0.95 v control, 8.93 +/- 1.02 fmol/mg of creatinine; P < 0.05). Plasma concentrations and urinary excretion of PAMP were significantly less for the patients with CGN compared with control subjects (0.91 +/- 0.08 v 1.23 +/- 0.20 fmol/mL; P < 0.05 and 25.0 +/- 3.0 v 35.0 +/- 3.6 fmol/mg of creatinine, respectively; P < 0. 05). The plasma AM concentration was negatively correlated with plasma renin activity (r = -0.58; P < 0.01) and aldosterone concentration (r = -0.40; P < 0.05). Urinary excretions of AM and PAMP showed significant correlations with urine excretion of sodium (r = 0.39; P < 0.05 and r = 0.49; P < 0.01, respectively). These findings suggest that AM and PAMP may have roles in the regulation of sodium in patients with CGN.