Labelling of prostaglandines with radioiodine and testing of the biological characteristics of iodinated derivatives

Prostaglandines have been labelled so far with tritium or 14C. Now the labelling with radioactive iodine keeps spreading for the biologically active proteins, therefore authors tried this technique to PGE1 and PGFsub(2α) preparations among prostaglandines with 125I and 131I according to Rosa's electrolytic method. Radio-chromatography showed that iodinated prostaglandine has nearly the same Rsub(f) value as the natural compound. The biological reactivity remained after labelling was measured with following three methods. The distribution of the compounds in rat organs agreed well with the literary data for not radioactive materials. Skin reactions also verified the effectiveness of the radioactive compound. In rabbit serum the iodinated and the natural PGFsub(2α) gave an immunological identity. From these results prostaglandines which are very sensitive compounds retain their important biological characteristics after a properly mild iodine labelling. (D.E.)