Self-radioiodination of iodogen.

Iodogen (1,3,4,6-tetrachloro-3alpha,6alpha-diphenylglucoluril) is commonly used for the radioiodination of proteins as an oxidative agent. The oxidative character of iodogen is not clear, but the two carbonyl groups in its structure probably have an essential role in its oxidizing character. In this study, the self-radioiodination of iodogen has been examined. It was observed that about 10-20% of the initial iodine radioactivity was consumed for the self-radioiodination of iodogen itself. On the other hand, the radioiodinated iodogen removed by ethyl alcohol from the iodogen-coated tubes showed clearly that no thyroid uptake was observed and that it was rapidly cleared out from the whole body of a rabbit administered with the radioiodinated iodogen by injection via the ear vein.