title: Improved extraction procedure and RIA for determination of arginine8-vasopressin in plasma: role of premeasurement sample treatment and reference values in children.
abstract: We optimized an RIA for measurement of arginine8-vasopressin (AVP) in plasma by use of 100-mg Isolute C18 columns for extraction, addition of a preincubation step, and use of maximal dilution of a commercially available antiserum. The detection limit was 0.06 ng/L when 0.5 mL of acidified plasma was extracted. The within- and between-run CVs (n = 16) at physiological concentrations were 5.8-10. 2% and 6.5-11.7%, respectively. Prolonged storage of blood at 25 degreesC, but not at 4 degreesC, led to a significant increase in measured plasma AVP concentrations. When plasma samples were prepared at several centrifugation speeds, plasma AVP was significantly correlated with the platelet count (r = 0.899; P <0. 001). This emphasizes the need for careful sample preparation to avoid contamination of plasma with platelet-bound AVP. Basal plasma AVP in 203 children and adolescents (105 males and 98 females; ages, 1 day to 18 years) averaged 1.1 +/- 0.6 ng/L. There was no significant difference between males and females and no correlation with age. In 16 healthy adult controls, plasma AVP averaged 1.0 +/- 0.5 ng/L.
authors.affiliation: Department of Pediatrics, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Kluge
authors.forename: S
authors.initials: S
authors.lastname: Riedl
authors.forename: B
authors.initials: B
authors.lastname: Erhart-Hofmann
authors.forename: J
authors.initials: J
authors.lastname: Hartmann
authors.forename: F
authors.initials: F
authors.lastname: Waldhauser
mesh_terms: D000293:Adolescent; D000328:Adult; D001127:Arginine Vasopressin / Q000097:blood* / Q000276:immunology; D001800:Blood Specimen Collection; D002138:Calibration; D002498:Centrifugation; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007106:Immune Sera; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010976:Platelet Count; D011863:Radioimmunoassay; D012016:Reference Values; D012076:Renal Agents / Q000097:blood* / Q000276:immunology; D012680:Sensitivity and Specificity
chemical_list: D007106:Immune Sera; D012076:Renal Agents; D001127:Arginine Vasopressin