RT Journal Article SR Electronic T1 Uptake of [111In-DTPA0]Octreotide in the Rat Kidney Is Inhibited by Colchicine and Not by Fructose JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 709 OP 713 VO 45 IS 4 A1 Rolleman, Edgar J. A1 Krenning, Eric P. A1 van Gameren, Arthur A1 Bernard, Bert F. A1 de Jong, Marion YR 2004 UL http://jnm.snmjournals.org/content/45/4/709.abstract 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 < 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.