Molecular forms of circulating atrial natriuretic peptides in human plasma and their metabolites

Atrial Natriuretic Peptide Increases Urodilatin in the Circulation

“…The lowest detectable concentrations were 40 fmol (140 pg), 35 fmol (136 pg), 5 fmol (15 pg) and 1.4 fmol (4.3 pg)/tube, whereas their nonspecific binding was 2.1, 2.5, 2.7 and 2.8% for long-acting natriuretic peptide, vessel dilator, kaliuretic peptide and ANP RIAs, respectively. Serial dilution of pooled plasma revealed excellent parallelism of standards and unknowns in these assays [12,14,16].…”

“…The kaliuretic peptide RIA also recognizes proANP 1-98 as well as kaliuretic peptide [31,34]. The vessel dilator and ANP RIAs recognize vessel dilator and ANP as distinct peptides in plasma, and neither of these assays recognizes proANP 1-98, long-acting natriuretic peptide, kaliuretic peptide or each other [5,16]. The intra-assay coefficients of variation for longacting natriuretic peptide, vessel dilator, kaliuretic peptide and ANP RIAs were 4.8, 5.3, 5.5 and 5.7%, respectively.…”

“…The long-acting natriuretic peptide RIA recognizes both long-acting natriuretic peptide (50%) and proANP 1-98 (50%) in plasma, as characterized by HP-GPC [5,16]. The kaliuretic peptide RIA also recognizes proANP 1-98 as well as kaliuretic peptide [31,34].…”

“…For this evaluation, plasma (5 ml) and urine (7 ml) at the various time points of this investigation were extracted with 100% ethanol (1:2 dilution) and then dried with low-flow nitrogen. The plasma and urine extracts were then resuspended in 100 Ìl of HP-GPC column mobile phase (10 mmol/l trifluoroacetic acid containing 0.3 mol/l sodium chloride and 30% acetonitrile) for HP-GPC assay as described previously [5,16]. These 100-Ìl samples were applied to a TSK-GEL G2000SW column (7.5 !…”

“…ANP) of this prohormone [7][8][9][10][11][12][13]. In addition, vessel dilator, long-acting natriuretic peptide and kaliuretic peptide circulate as distinct entities after having been proteolytically cleaved from the rest of the N-terminus by proteases [5,[14][15][16]. Vessel dilator, longacting natriuretic peptide, and ANP bind to specific receptors [17][18][19] and then each of these peptides enhances the particulate form of the enzyme guanylate cyclase (EC 4.6.1.2) as part of their mechanism(s) of action [6,20,21].…”