Synthesis and iodine-125 labelling of glucuronide compounds for combined chemo- and radiotherapy of cancer

A correlative study between 99mTc-ESTCPTA and 99mTc-MIBI in rats

Tissue distribution of the 99mTc labeled derivative of the estrogen compound 3,17-alpha-estradiolyl propyl 1,4,8,11-tetraazacyclotetradecanyl-l-(4-methylbenzoic acid) ester (ESTCPTA), which has an 3,17-alpha-estradiolyl propinol coupled to l-(4-methylbenzoic acid)1,4,8,11-tetraazacyclotetradecane (CPTA), was compared to 99mTc-MIBI (methoxyisobutyl isonitrile) in female Albino Wistar rats. Tissues of interest included lung, liver, heart, kidneys, spleen, stomach, intestines, pancreas, muscle, blood, breast, ovary, fat, and uterus. 99mTc-ESTCPTA uptake by the uterus and ovary, as ER-rich tissues, was highly selective. Maximum uptakes for 99mTc-MIBI and 99mTc-ESTCPTA are 90 min in breast, ovary and uterus. The pancreas also showed significant receptor saturated and unsaturated ratios for 99mTc-ESTCPTA. Results are sufficiently encouraging to generate further evaluation of these and related compounds as possible estrogen receptor based tumor imaging and therapeutic agents in estrogen-rich tissues.

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.