Ex vivo evaluation of N-(3-[18F]fluoropropyl)-2β-carbomethoxy-3β-(4-fluorophenyl)nortropane in rats

Koivula, Teija; Marjamäki, Päivi; Haaparanta, Merja; Fagerholm, Veronica; Grönroos, Tove; Lipponen, Tiina; Perhola, Outi; Vepsäläinen, Jouko; Solin, Olof

doi:10.1016/j.nucmedbio.2007.09.006

« Previous Next »Nuclear Medicine and Biology
Volume 35, Issue 2 , Pages 177-183, February 2008

Ex vivo evaluation of N-(3-[¹⁸F]fluoropropyl)-2β-carbomethoxy-3β-(4-fluorophenyl)nortropane in rats

Teija Koivula
- Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
Päivi Marjamäki
- MediCity PET Laboratory, Turku PET Centre, Tykistökatu 6 A, FI-20520 Turku, Finland
Merja Haaparanta
- MediCity PET Laboratory, Turku PET Centre, Tykistökatu 6 A, FI-20520 Turku, Finland
Veronica Fagerholm
- MediCity PET Laboratory, Turku PET Centre, Tykistökatu 6 A, FI-20520 Turku, Finland
Tove Grönroos
- MediCity PET Laboratory, Turku PET Centre, Tykistökatu 6 A, FI-20520 Turku, Finland
Tiina Lipponen
- Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
Outi Perhola
- Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
Jouko Vepsäläinen
- Department of Chemistry, University of Kuopio, P.O. Box 1627, FI-70210 Kuopio, Finland
Olof Solin
- Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
- MediCity PET Laboratory, Turku PET Centre, Tykistökatu 6 A, FI-20520 Turku, Finland
- Corresponding author. Tel.: +358 2 3132851; fax: +358 2 2818191.

Received 11 September 2007; accepted 27 September 2007.

Abstract

Introduction

The dopamine transporter (DAT) ligand N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4-fluorophenyl)nortropane (β-CFT-FP) was labeled with fluorine-18, and its biodistribution was evaluated in rats ex vivo.

Methods

The distribution of ¹⁸F radioactivity in the brain and peripheral organs and tissues was determined at several time points 5–120 min after intravenous injection of [¹⁸F]β-CFT-FP.

Results

The highest brain uptake of [¹⁸F]β-CFT-FP was localized in the striatum; limbic structures also exhibited high uptake. Low uptake was found in the cerebellum. The highest ratio of striatum-to-cerebellum uptake, already reached within 5 min, was 3.1. Pretreatment with the selective DAT inhibitor GBR12909 significantly decreased [¹⁸F]β-CFT-FP uptake in the striatum. In most peripheral tissues, the highest uptake was found at 5 min, indicating fast washout of the radioligand. Some accumulation of ¹⁸F radioactivity was seen in bone as a function of time, reflecting defluorination of the radioligand.