title: Atrial natriuretic factor in human plasma.
abstract: A reproducible and sensitive radioimmunoassay (RIA) was developed to measure ANF in human plasma. Immunoreactive ANF was extracted from plasma with Sep-Pak cartridges, using 0.2% ammonium acetate (pH 4) with acetonitrile. The sensitivity of the assay was 3.9 pg/ml. The coefficient of variance for inter-assay and intra-assay was 16.8% and 6.8%, respectively. In normal healthy subjects (n = 67), ANF content was 11.9 +/- 1.3 pg/ml (mean +/- SEM). Significantly-higher ANF concentrations were found in proximal coronary sinus blood, being 6 to 37 times greater than in the peripheral circulation. Comparison of the prior extraction method with direct RIA revealed a good correlation (r = 91) in samples containing higher than 100 pg/ml ANF. No correlation was observed with lower values. The elution profiles of reverse-phase HPLC of peripheral and coronary sinus plasma extracts were similar but somewhat complex, with the main immunoreactive peak corresponding to a low-molecular-weight peptide.
mesh_terms: D000328:Adult; D000368:Aged; D009320:Atrial Natriuretic Factor / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012016:Reference Values
chemical_list: D007106:Immune Sera; D007457:Iodine Radioisotopes; C472955:NPPA protein, human; D009320:Atrial Natriuretic Factor