| Title | Cyclic Minigastrin Analogues for Gastrin Receptor Scintigraphy with Technetium-99m: Preclinical Evaluation. | | Author(s) | von Guggenberg E, Sallegger W, Helbok A, Ocak M, King R, Mather SJ, Decristoforo C | | Institution | Department of Nuclear Medicine, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. | | Source | J Med Chem 2009 Jul 10. | | Abstract | Two cyclized minigastrin analogues for gastrin receptor scintigraphy were synthesized and derivatized with HYNIC at the N-terminus for labeling with (99m)Tc. Radiolabeling efficiency, stability, cell internalization, and receptor binding on CCK-2 receptor expressing AR42J cells were studied and the biodistribution evaluated in tumor bearing nude mice, including NanoSPECT/CT imaging. Metabolites in urine, liver, and kidneys were analyzed by radio-HPLC. Radiolabeled cyclic MG showed high stability in vitro and receptor mediated uptake in AR42J cells. In the animal tumor model, fast renal clearance and low nonspecific uptake in most organs were observed. A tumor uptake >3% was calculated ex vivo 1 h p.i. for both (99m)Tc-EDDA-HYNIC-cyclo-MG1 and (99m)Tc-EDDA-HYNIC-cyclo-MG2. In an imaging study with (99m)Tc-EDDA-HYNIC-cyclo-MG1, the tumor was clearly visualized. The metabolite analysis indicated rapid enzymatic degradation in vivo. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19591486 |
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