N‐[(1‐Ethyl‐2‐pyrrolidinyl)methyl]‐5‐(2‐[18F]fluoroethyl)‐2,3‐dihydroben‐zofuran‐7‐carboxamide ([18F]5) was synthesized via nucleophilic substitution with K18F/Kryptofix222 complex in 5.4∼6.8% radiochemical yields with a specific activity of larger than 5.6 TBq/mmol (150 Ci/mmol) at the end of the 110 minutes synthetic period. Its in vivo affinity toward CNS dopamine D2 receptors was investigated using rats in order to evaluate as a radiotracer for the PET (positron emission tomography) study of the dopamine D2 receptors. In biodistribution experiments, [18F]5 exhibited striatal accumulation, although the whole brain radioactivity was cleared rapidly. The striatal/cerebellar radioactivity ratio, which corresponds to the ratio of a brain D2 receptor‐rich to poor region, gradually increased to about 12 at 60 minutes after the injection. The striatal uptake was inhibited with pretreated haloperidol, a dopamine D2 antagonist, indicating that the striatal accumulation was due to the specific binding with D2 receptors. Thus, [18F]5 appears to be a potential in vivo radiotracer for dopamine D2 receptors.
|ジャーナル||Journal of Labelled Compounds and Radiopharmaceuticals|
|出版物ステータス||出版済み - 12 1993|
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Radiology Nuclear Medicine and imaging
- Drug Discovery
- Organic Chemistry