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[ 18 F]CFT ([ 18 F]WIN 35,428), a radioligand to study the dopamine transporter with PET: Biodistribution in rats
Author(s) -
Haaparanta Merja,
Bergman Jörgen,
Laakso Aki,
Hietala Jarmo,
Solin Olof
Publication year - 1996
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/(sici)1098-2396(199608)23:4<321::aid-syn10>3.0.co;2-#
Subject(s) - biodistribution , radioligand , dopamine transporter , radiochemistry , dopamine , dopamine plasma membrane transport proteins , chemistry , transporter , nuclear medicine , medicine , endocrinology , receptor , dopaminergic , biochemistry , in vitro , gene
We describe the 18 F‐radiolabelling synthesis ( 18 F; T1/2 = 109.8 min) of 2‐β‐carbomethoxy‐3β‐(4‐fluorophenyl)tropane (also known as CFT or WIN 35,428) and the biodistribution of this compound in rats. 18 F‐labelled CFT has high chemical and radiochemical purity and relatively high specific radioactivity [specific radioactivity up to 14.8 GBq/μmol (400 mCi/μmol) at end of synthesis]. Striatum to cerebellum radioactivity uptake ratios were calculated from digitised images of rat brain slices recorded with a phosphoimaging device, the maximum ratio of about 10 was obtained at 2 h postinjection. Pretreatment of the rats with a specific dopamine transport inhibitor, GBR 12909, showed that CFT binding is specific in striatum. The highest accumulation of 18 F‐radioactivity was found in the liver, urine, striatum, and kidney of the rat. Clearance from blood was rapid. The uptake in bone was low, indicating that [ 18 F]CFT is not defluorinated. The relatively long half‐life of 18 F makes it possible to study the uptake of [ 18 F]CFT in the brain, as equilibrium between specific and non‐specific binding is reached. This will improve the signal to noise ratio as compared to positron emission tomography (PET) studies with [ 11 C]CFT ( 11 C; T 1/2 = 20.4 min). CFT labelled with 18 F is clearly a promising radioligand for PET studies of the dopamine transporter system in humans. © 1996 Wiley‐Liss, Inc.