A novel technique for the preparation of (125)I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabino-furanosyl) uracil [correction of urail] and its biodistribution pattern in Kunming mice.

In this study, a novel technique for the preparation of (125)I-5-trimethylstannyl-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) urail (FIAU) was developed, (125)I-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 ((125)I). 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 (125)I-FIAU in Kunming mice was also detected. The results showed that (125)I-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. (125)I-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 (125)I-FIAU from the blood pool. (125)I-FIAU was mostly excreted by kidneys. (125)I-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 (125)I-FIAU is easy, highly effective and stable in vivo. The biodistribution of (125)I-FIAU in Kunming mice showed it can serve as an imaging probe for myocardial reporter genes.