PREPARATION AND EVALUATION OF 17-ALPHA-[I-125]IODOVINYL-11-BETA-METHOXYESTRADIOL AS A HIGHLY SELECTIVE RADIOLIGAND FOR TISSUES CONTAINING ESTROGEN-RECEPTORS - CONCISE COMMUNICATION

Abstract

The moxestrol analog 17.alpha.-[125I]iodovinyl-11.beta.-methoxyestradiol was prepared in 95% radiochemical yield from the corresponding 17.alpha.-(tributylstannyl)vinyl compound and no-carrier-added sodium [125I]iodide. The new radioligand was evaluated in immature female rats to determine the uptake in and selectivity for tissues containing estrogen receptors. At 1, 2 and 6 h after injection, the agent demonstrates both high selectivity (uterus to blood ratio) and a high concentration in the target tissue. These values are considerably better than those previously reported for IVE2 [E-17.alpha.-[125I]iodovinylestradiol] or for the 16.alpha.-radiohalogenated estradiols. The compound''s biologic properties and its ease of preparation suggest that it would be a likely candidate for clinical use as an estrogen-receptor-seeking radiopharmaceutical [for diagnosis of human breast cancer].