Fate of 6-deoxy-6-[I-123]iodo-D-glucose in normal and diabetic rats

The D-glucose analog 6-deoxy-6-[I-123]iodo-D-glucose (G-DIG) was recently p roposed as a potential tracer for the ill vivo characterization of D-glucos e transport in distinct cell types. In this study, the validity of such a p roposal was investigated in both control and streptozotocin-induced diabeti c rats. 6-DIG was injected intravenously in either control or diabetic mts. The fate of 6-DIG was assessed by scintigraphy of the injected animals, bl ood and urine sampling, and measurement of tissue radioactivity at the time of sacrifice, 140 min after 6-DIG injection. The half-life for 6-DIG in pl asma and its accumulation in kidney and urinary bladder indicated that it w as mainly eliminated from the body by glomerular filtration. The urinary el imination of 6-DIG was accelerated, however, in the polyuric diabetic rats. Bile formation also apparently contributed to the clearance of 6-DIG. Its uptake by liver, heart and muscles yielded values lower than blood concentr ation. The usefulness of 6-DIG as a tracer for D-glucose transport in selec ted organs in the perspective of clinical application, e.g. by single photo n emission computed tomography, requires further investigations.