PT - JOURNAL ARTICLE AU - Edgar J. Rolleman AU - Eric P. Krenning AU - Arthur van Gameren AU - Bert F. Bernard AU - Marion de Jong TI - Uptake of [<sup>111</sup>In-DTPA<sup>0</sup>]Octreotide in the Rat Kidney Is Inhibited by Colchicine and Not by Fructose DP - 2004 Apr 01 TA - Journal of Nuclear Medicine PG - 709--713 VI - 45 IP - 4 4099 - http://jnm.snmjournals.org/content/45/4/709.short 4100 - http://jnm.snmjournals.org/content/45/4/709.full SO - J Nucl Med2004 Apr 01; 45 AB - The high renal uptake of radiolabeled somatostatin analogs is dose limiting. Lowering this uptake permits higher radioactivity doses and, thus, tumor doses to be administered. We tested the effects of the microtubule drug colchicine on renal uptake of [111In-DTPA0]octreotide. Also, the effects of fructose were tested. Methods: Organ radioactivity 24 h after injection of [111In-DTPA0]octreotide was determined in rats. Results: Coinjection of 1 mg of colchicine per kilogram did not influence renal uptake of [111In-DTPA0]octreotide, whereas this dose administered 5 h before [111In-DTPA0]octreotide resulted in significant renal uptake reduction (63%). d-Lysine plus colchicine reduced the uptake by 76% (P &lt; 0.01 vs. d-lysine alone). Liver and blood radioactivity levels were significantly elevated by colchicine. Fructose did not affect the biodistribution of [111In-DTPA0]octreotide. Conclusion: Renal uptake of [111In-DTPA0]octreotide is dependent on microtubule function in rats. The addition of colchicine to amino acid protocols may permit administration of higher doses, improving the therapeutic window of peptide receptor radionuclide therapy.