skip to main content

Title: Radioimmunoassay of 5-hydroxyindole acetic acid using an iodinated derivative

A radioimmunoassay for the main catabolite of serotonin, 5-hydroxyindole acetic acid (5-HIAA), was developed by using specific antibodies and iodinated derivative. The synthesis of a /sup 125/I-iodinated analog was performed by coupling 5-HIAA to (125I-)glycyl-tyrosine without any contact between 5-HIAA and iodine or chloramine T. It was purified on a G25 Sephadex column and diluted in citrate buffer up to 2.5 X 10(5) cpm/ml. Antibodies were obtained by coupling 5-HIAA to human serum albumin with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and tested by equilibrium dialysis. After the third immunogen injection, the four rabbits gave antisera capable of binding 50% of iodinated 5-HIIA-glycyl-tyrosine at 1/2000 final dilution. A chemical conversion of the biological samples gives to the antigen molecules a better resemblance to the immunogen, thus conferring a 100-fold gain in specificity and sensitivity. This assay allows 5-HIAA to be determined in small amounts of tissue, blood, cerebrospinal fluid or perfusate without purification with a sensitivity threshold below 0.1 ng. Some applications in cat and rat are presented.
Authors:
;
Publication Date:
OSTI Identifier:
5579169
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Pharmacol. Exp. Ther.; (United States); Journal Volume: 217:3
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; IODINE 125; ISOTOPE APPLICATIONS; SEROTONIN; RADIOIMMUNOASSAY; ANTIBODIES; CATABOLISM; CATS; RATS; TYROSINE; AMINES; AMINO ACIDS; ANIMALS; AUTONOMIC NERVOUS SYSTEM AGENTS; AZOLES; BETA DECAY RADIOISOTOPES; CARBOXYLIC ACIDS; DAYS LIVING RADIOISOTOPES; DRUGS; ELECTRON CAPTURE RADIOISOTOPES; HETEROCYCLIC COMPOUNDS; HYDROXY ACIDS; HYDROXY COMPOUNDS; INDOLES; INTERMEDIATE MASS NUCLEI; IODINE ISOTOPES; ISOTOPES; MAMMALS; METABOLISM; NEUROREGULATORS; NUCLEI; ODD-EVEN NUCLEI; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PYRROLES; RADIOASSAY; RADIOISOTOPES; RADIOPROTECTIVE SUBSTANCES; RODENTS; SYMPATHOMIMETICS; TRACER TECHNIQUES; TRYPTAMINES; VERTEBRATES 550201* -- Biochemistry-- Tracer Techniques