Human atrial natriuretic peptide in non-dialyzed patients with chronic renal failure

The role of human atrial natriuretic peptide (alpha-hANP) in the regulation of blood pressure (BP) and extracellular fluid volume (ECFV) remains elusive. This is of particular interest in chronic renal failure, in which first, increased sodium and water retention plays a major pathogenetic role in the development of hypertension, and second, altered secretion and/or metabolism of alpha-hANP may contribute to fluid volume and BP regulation. In the present study the relationship between renal function, BP, and circulating alpha-hANP was investigated in 16 non-dialyzed patients with stable chronic renal failure (CRF) without edema. Analysis of potential molecular heterogeneity of immunoreactive (ir) ANP was performed by gel permeation chromatography of plasma extracts from normotensive patients with CRF. Serum creatinine concentrations averaged 435 +/- 76 mumol/l ranging from 127 to 1187 mumol/l, systolic and diastolic BP averaged 158 +/- 4 and 94 +/- 2 mmHg, respectively. Plasma alpha-hANP concentrations ranged from 5 to 75 with a mean of 23 +/- 4 pmol/l as compared to a mean of 10 +/- 1 pmol/l in healthy volunteers (p less than 0.05). A significant linear correlation between plasma alpha-hANP and serum creatinine concentrations (r = 0.92) was observed; a weaker correlation was found between mean arterial pressure and alpha-hANP (r = 0.66). Chromatographic analysis revealed considerable amounts of higher molecular weight circulating ir-ANP, approximately 15,000 Da, in addition to the biologically active small mol wt ANP.(ABSTRACT TRUNCATED AT 250 WORDS)