title: A highly sensitive and rapid radioimmunoassay for the determination of arginine8-vasopressin.
abstract: A highly sensitive radioimmunossay for arginine8-vasopressin (argipressin; INN) measurement was developed using Amberlite XAD 2 resin columns to extract arginine8-vasopressin from acidified human plasma. Arginine8-vasopressin was determined by a rapid radioimmunoassay method (2 x 20 h) using a specific antibody and 125I-labelled antigen. The bound fraction was separated by adsorption of the free fraction onto bovine serum albumin-coated charcoal; this resulted in low unspecific binding of less than 2%. Recovery experiments in the physiological range resulted in a mean (+/- SEM) recovery of 88 +/- 3%. The radioimmunoassay consistently yielded a detection limit of 0.3 ng/l (ED90) and a mean 50% binding intercept (ED50) of 3.5 ng/l. Arginine8-vasopressin immunoreactivity was characterized by reverse-phase high performance liquid chromatography, which confirmed the specificity of the assay. Serial plasma dilution curves paralleled the standard curve. The intra- and inter-assay variations were 9.4% and 15%, respectively. Arginine8-vasopressin concentrations in healthy subjects were determined in normal hydration status (2.2 +/- 0.3 ng/l; n = 11), as well as during suppression by water immersion (1.5 +/- 0.2 ng/l; n = 11) or by water loading (1.6 +/- 0.2 ng/l; n = 8). Thus, this assay allows for a sensitive, accurate and rapid quantification of plasma arginine8-vasopressin concentrations.
authors.affiliation: Medizinische Klinik II, Universität München.
authors.forename: A L
authors.initials: AL
authors.lastname: Gerbes
authors.forename: R
authors.initials: R
authors.lastname: Witthaut
authors.forename: W K
authors.initials: WK
authors.lastname: Samson
authors.forename: W
authors.initials: W
authors.lastname: Schnizer
authors.forename: A M
authors.initials: AM
authors.lastname: Vollmar
mesh_terms: D001127:Arginine Vasopressin / Q000097:blood*; D005069:Evaluation Studies as Topic; D006801:Humans; D011863:Radioimmunoassay / Q000379:methods* / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity
chemical_list: D001127:Arginine Vasopressin