In vitro and in vivo evaluation of new radiolabeled neurotensin(8-13) analogues with high affinity for NT1 receptors

The potential utility of neurotensin (NT) in cancer diagnosis and therapy i s limited by its rapid degradation. New stabilized analogues were synthesiz ed, labeled with [Tc-99m] and screened in vitro and in vivo. High affinity and rapid internalization were obtained in binding assays. Despite their lo nger human plasma half-lives, a rapid degradation was observed with low con centrations as used in biodistribution tests. The tumor uptake rates were r ather low but tumor/blood ratios increased according to the stability raise . (C) 2001 Elsevier Science Inc. All rights reserved.