Urinary and plasma urodilatin measured by a direct RIA using a highly specific antiserum

Clin Chem. 1998 Dec;44(12):2524-9.

Abstract

Urodilatin (95-126) (URO) appears to play a major physiologic role in fluid homeostasis and produces major changes when administered intravenously. Here we describe a monospecific, high-affinity antiserum against URO with no cross-reactivity (<0.01%) against the structural highly homologous atrial natriuretic peptide 99-126 (ANP-99-126), ANP analogs, and related peptides such as brain natriuretic peptide. A competitive RIA was developed, based on this antiserum. Urine samples with or without ethanol extraction and plasma samples without pretreatment were analyzed by the RIA, which had a detection limit of 10.5 ng/L, a linear measuring range between 10.5 and 1000 ng/L, and recoveries of 93-102% in urine and 90-104% in plasma. The intraassay CVs were 8.2% and 8.1% for urine samples with 269 and 669 ng/L URO; the interassay CV was 9.7% at 839 ng/L. Using this assay, we present URO data for urine from healthy volunteers receiving low and routine sodium diets and from clinical urine specimens; we also present pharmacokinetic data for URO in plasma from patients suffering from bronchial asthma and treated by URO infusion.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase II

MeSH terms

  • Animals
  • Antibody Specificity
  • Asthma / drug therapy
  • Asthma / metabolism
  • Atrial Natriuretic Factor / analysis*
  • Atrial Natriuretic Factor / blood
  • Atrial Natriuretic Factor / immunology
  • Atrial Natriuretic Factor / urine
  • Bronchodilator Agents / analysis*
  • Bronchodilator Agents / blood
  • Bronchodilator Agents / immunology
  • Bronchodilator Agents / urine
  • Cardiac Catheterization
  • Diuretics / analysis*
  • Diuretics / blood
  • Diuretics / immunology
  • Diuretics / urine
  • Immune Sera*
  • Infusions, Intravenous
  • Male
  • Peptide Fragments / analysis*
  • Peptide Fragments / blood
  • Peptide Fragments / immunology
  • Peptide Fragments / urine
  • Rabbits
  • Radioimmunoassay
  • Sheep
  • Sodium, Dietary / administration & dosage

Substances

  • Bronchodilator Agents
  • Diuretics
  • Immune Sera
  • Peptide Fragments
  • Sodium, Dietary
  • Ularitide
  • Atrial Natriuretic Factor