Kochupillai N, Yalow R S
Endocrinology. 1978 Jan;102(1):128-35. doi: 10.1210/endo-102-1-128.
A modified chloramine-T method is described for the preparation of several radioiodothyronines by an exchange reaction, which results in low specific activity preparations, or by an addition reaction, which yields radioiodothyronines with specific activities up to 7 mCi/microgram. Purification by paper chromatography is shown to be more convenient than by LH-20 chromatography and provides better resolution among the various thyronines. Radioiodothyronines with only a single iodine atom in the outer (3,5,3'-triiodothyronine and 3,3'-diiodothyronine) are stable for several months when stored in organic solvents. The least stable radioiodothyronines are those with two 125I atoms in the outer ring (3,3',5'-triiodothyronine (rT3) produced from 3-iodothyronine and thyroxine (T4) from 3,5-diiodothyronine). The stability of rT3 and T4 stored in human plasma at 4 C is much greater than when stored in buffer at the same pH. The use of high specific activity [125I]rT3 has permitted the development of a radioimmunoassay with a sensitivity of 1 pg rT3/ml incubation volume.
本文描述了一种改进的氯胺 -T法，用于通过交换反应制备几种放射性碘甲状腺原氨酸（该反应会产生低比活制剂），或通过加成反应制备（该反应可产生比活高达7 mCi/μg的放射性碘甲状腺原氨酸）。结果表明，用纸色谱法纯化比用LH -20色谱法更方便，并且在各种甲状腺原氨酸之间能提供更好的分离效果。在外环仅含单个碘原子的放射性碘甲状腺原氨酸（3,5,3'-三碘甲状腺原氨酸和3,3'-二碘甲状腺原氨酸），储存在有机溶剂中时可稳定数月。最不稳定的放射性碘甲状腺原氨酸是那些在外环含有两个125I原子的（由3 -碘甲状腺原氨酸产生的3,3',5'-三碘甲状腺原氨酸（rT3）和由3,5 -二碘甲状腺原氨酸产生的甲状腺素（T4））。rT3和T4在4℃储存在人血浆中的稳定性远高于储存在相同pH值的缓冲液中。使用高比活的[125I]rT3使得能够开发一种灵敏度为1 pg rT3/孵育体积的放射免疫测定法。
