In this study, a novel technique for the preparation of 125I-5-trimethylstannyl-1-（2-deoxy-2-fluoro-beta-D-arabinofuranosyl） urail （FIAU） was developed, 125I-FIAU biodistribution profile was detected in Kunming mice and the possibility of using FTAU radio-labeling for reporter gene imaging was explored. 5-trimethylstannyl-1-（2-deoxy-2-fluoro-beta-D-arabinofuranosyl） urail （FTAU） was labeled with radioiodine （125I）. A rotary evaporation method was used to remove excess methanol. The reactant was purified through a Sep-Pak C18 reversal phase column. The radiochemical purity and in vivo stability were determined using silica gel thin layer chromatography （TLC）. The biodistribution of 125I-FIAU in Kunming mice was also detected. The results showed that 125I-FIAU could be radiolabeled effectively with FTAU, with mean labeling rate being （81±0.38）% （n =5）. The mean radiochemical purity of （98.01±0.40）% （n=5） was achieved after a reversal phase Sep-park column purification. 125I-FIAU was stable when incubated in normal human serum or in saline at 37°C, with a radiochemical purity 〉96% during a 0.5-24 h time period. Biological experiments exhibited rapid clearance of 125I-FIAU from the blood pool. 125I-FIAU was mostly excreted by kidneys. 125I-FIAU in myocardium dropped conspicuously after 8 h and there was hardly retention at 24 h. We were led to concluded that the new method of radioiodinization of FTAU for the preparation of 125I-FIAU is easy, highly effective and stable in vivo. The biodistribution of 125I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.
