title: Radioimmunoassay for circulating human guanylin.
abstract: A highly specific and sensitive radioimmunoassay for circulating human guanylin (guanylin-22-115) has been developed. Antibodies were raised against the amino-terminus (positions 4-16) of the peptide. Western blot analysis confirmed that the antibody selected for radioimmunoassay recognizes circulating high molecular weight (10.3 kDa) guanylin. Extraction and purification of guanylin from blood hemofiltrate and from blood plasma showed that circulating guanylin is detectable in corresponding amounts by the radioimmunoassay and by a specific bioassay. In 30 healthy subjects, the mean plasma concentration of immunoreactive (IR) guanylin was 42 +/- 3 fmol/ml. In 22 patients with chronic renal insufficiency, the concentrations of IR-guanylin were significantly enhanced (1,074 +/- 24 fmol/ml), indicating that kidneys metabolize and/or eliminate the circulating hormone.
authors.affiliation: Lower Saxony Institute for Peptide Research, Hannover, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kuhn
authors.forename: H
authors.initials: H
authors.lastname: Kulaksiz
authors.forename: K
authors.initials: K
authors.lastname: Adermann
authors.forename: G
authors.initials: G
authors.lastname: Rechkemmer
authors.forename: W G
authors.initials: WG
authors.lastname: Forssmann
mesh_terms: D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005768:Gastrointestinal Hormones; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D045265:Natriuretic Peptides; D010455:Peptides / Q000097:blood*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D005768:Gastrointestinal Hormones; D045265:Natriuretic Peptides; D010455:Peptides; C072685:guanylin