Labelling of octapeptide neurohormones for in vitro studies. Radioimmunologic assay for arginine-vasopressin.
Synthetic arginine-vasopressin (AVP), oxytocin (OXY) and arginine-vasotocin (AVT) were labelled with radioiodine at a moderate specific activity. The purity of the labelled octapeptides was checked by descendent paper chromatography in butanol-acetic acid-water (4 : 1 : 5 v/v) after a double filtration on a Sephadex G-25 column of the labelling mixtures. The rabbit anti-AVP serum bound 125I--AVP, the highest binding belling observed on the descendent eluates from the Sephadex column. The antiserum is specific to AVP, no binding being observed will AVT or oxytocin. The sensitivity of a RIA system using 125I--AVP, commercial anti-AVP serum and polyethyleneglycol separation technique, was of 5 pg/ml in terms of AVP with a biological activity of 385 IU/mg. The validity of the assay was tested on five patients (two with diabetes inspidus (DI) and three with other endocrine diseases) submitted to dehydration of hydration tests.
D001127:Arginine Vasopressin / Q000032:analysis*; D002854:Chromatography, Paper; D006801:Humans; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D010121:Oxytocin / Q000032:analysis; D011863:Radioimmunoassay; D014668:Vasotocin / Q000032:analysis
D007457:Iodine Radioisotopes; D001127:Arginine Vasopressin; D010121:Oxytocin; D014668:Vasotocin