HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Nakamura, Y. Articles by Solomon, D. H. Search for Related Content PubMed PubMed Citation Articles by Nakamura, Y. Articles by Solomon, D. H.

Preparation of High-Specific-Activity Radioactive Iodothyronines and Their Analogues

UCLA Center for the Health Sciences, Los Angeles, California

Correspondence: For reprints contact: Inder J. Chopra, Dept. of Medicine, UCLA Center for the Health Sciences, Los Angeles, CA 90024.

ABSTRACT

In order to obtain radioactive iodothyronines of high specific activity, suitable for use in radioimmunoassays, we have used chloramine-T as the oxidizing agent to attach radioiodine to various iodothyronines including 3-iodo-L-thyronine (3-T₁), 3'-iodo-L-thyronine (3'-T₁), 3–5-diiodo-L-thyronine (3,5-T₂), 3,3'-diiodo-L-thyronine (3,3'-T₂), 3,5,3'-triiodo-L-thyronine (T₃) and some of their analogues, e.g., 3,5-diiodothyropropionic acid (3,5-Diprop), and 3,5,3'-triiodothyropropionic acid (Triprop). Radioiodine incorporated into iodothyronines was separated from unreacted radioiodide by column chromatography using LH-20 Sephadex, and the various radioactive iodothyronines produced during iodination were separated by descending paper chromatography using hexane, tertiary amyl alcohol, and ammonia. In the case of each substrate, radioactive products produced were those that would result from the radiolabeling of the 3' and/or 5' position of the iodothyronine molecule; compounds that would be produced from radiolabeling of the inner ring of the iodothyronine molecule were never detected. While exchange labeling of outer-ring iodine atoms did occur, addition of an iodine atom to the outer ring was far more common. Our data suggest that (a) the chloramine-T method is practical and convenient to render any iodothyronine (or its analogue) radioactive in the outer ring; and (b) specific activity of the radioactive product, and yield of iodination, are particularly high when the substrate for iodination has one less iodine atom in the outer ring than the one desired.

This article has been cited by other articles:

				G. Pinna, O. Brodel, T. Visser, A. Jeitner, H. Grau, M. Eravci, H. Meinhold, and A. Baumgartner Concentrations of Seven Iodothyronine Metabolites in Brain Regions and the Liver of the Adult Rat Endocrinology, May 1, 2002; 143(5): 1789 - 1800. [Abstract] [Full Text] [PDF]

				G. Pinna, L. Hiedra, H. Meinhold, M. Eravci, H. Prengel, O. Brödel, K.-J. Gräf, G. Stoltenburg-Didinger, M. Bauer, and A. Baumgartner 3,3'-Diiodothyronine Concentrations in the Sera of Patients with Nonthyroidal Illnesses and Brain Tumors and of Healthy Subjects during Acute Stress J. Clin. Endocrinol. Metab., September 1, 1998; 83(9): 3071 - 3077. [Abstract] [Full Text]