title: A new sensitive radioimmunoassay for plasma arginine vasopressin.
abstract: A new extremely sensitive radioimmunoassay to measure plasma AVP has been developed. Antiserum to AVP of high affinity (Keq = 1.1 X 10(12) 1/mol), raised in rabbits, showed little cross-reaction with related analogues (LVP less than 0.03%, AVT, DDAVP, OXT less than 0.01). The specific activity of 125I-AVP (chloramine T method) was 1400-1750 Ci/mmol. The limit of detection of plasma AVP, after extraction of 2 ml plasma with Florisil, was 0.3 pmol/1. Coefficient of variations of plasma control (2 pmo1/1) were 9.7% (intraassay) and 15.3% (inter-assay), n = 15. Osmotic stimulation by hypertonic saline infusion caused a linear response in plasma AVP in normal subjects, but plasma AVP remained undetectable in patients with cranial diabetes insipidus. Suppression of AVP secretion by a standard oral water load and by alcohol and fluid in volunteers produced low or undetectable values of plasma AVP. In a patient with the syndrome of inappropriate antidiuresis, plasma AVP concentration was grossly elevated.
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood*; D001515:Beer; D003919:Diabetes Insipidus / Q000097:blood; D005260:Female; D006801:Humans; D007106:Immune Sera; D008832:Microchemistry; D011817:Rabbits; D011863:Radioimmunoassay
chemical_list: D007106:Immune Sera; D001127:Arginine Vasopressin