Derivatives of iodothyronine compounds and their use in an assay for the free iodothyronine compounds

摘要

Novel amides of an iodothyronine compound such as tri-iodothyronine (T3) or thyroxine (T4) with an amino-acetic acid compound such as nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA) or diethylene-triamine pentaacetic acid (DTPA) may be labelled, e.g. radioactively labelled with 1-125, to give labelled derivatives useful in assays of a free thyroid hormone in a biological fluid which also contains the thyroid hormone bound to one or more natural binders. The novel compound T4 EDTA is shown to bind much more strongly to antibodies to T4 than to the natural protein binders in the biological fluid.