Radio-immunoassay of atrial natriuretic peptide in human plasma.

A highly sensitive and accurate radio-immunoassay for measurement of atrial natriuretic peptide in human plasma has been established. All reagents are commercially available. The sensitivity of the method is 1 pmol/l. The 50% intercept of the standard curve was at 22 fmol/tube and inter- and intra-assay precision were 10.9 and 5.3%, respectively. Plasma immunoreactive atrial natriuretic peptide levels measured in healthy subjects, during pregnancy, and in congestive cardiac failure were within the limits reported in the literature.