Difference in brain distributions of carbon 11-labeled 4-hydroxy-2(1H)-quinolones as PET radioligands for the glycine-binding site of the NMDA ion channel

Synthesis and biological evaluation of radio-iodinated benzimidazoles as SPECT imaging agents for NR2B subtype of NMDA receptor

“…40,41 Therefore, this study indicated that [ Similar to this study, previously reported imaging agents for NR2B subunit of NMDA receptor showed consistent accumulation pattern with the expression of NR2B subunit and high specificity to NR2B rich region only under in vitro condition but not in vivo. [13][14][15][16][17][18][19] Moreover, similar binding characters were observed in the radioligands for other binding sites of NMDA receptor, such as ion-channel site 43,44 and glycine site [45][46][47] . Kew et.…”

Synthesis and characterization of 11C‐labeled benzyl amidine derivatives as PET radioligands for GluN2B subunit of the NMDA receptors

“…It has been reported that radiotracers targeting the GluN2B subunit show consistent in vitro binding with GluN2B in the brain tissues of both rats and mice . In addition, we and others, through several studies using in vitro experiments with rat brain slices and in vivo experiments, have shown the biodistribution of radiotracers for the GluN2B subunit and the glycine‐binding sites of the NMDA receptors. Therefore, we designed the experiments in this pilot study for direct comparison with the findings of previous reports.…”

“…Carbon‐11 was generated by theN(p, α) 11 C nuclear reaction using a CYPRIS HM‐18 cyclotron (Sumitomo Heavy Industries, Ltd.). Preparation of [ 11 C]CH 3 I and subsequent 11 C‐methylation were carried out automatically using the synthetic apparatus for 11 C‐labeled compounds described in our previous reports . All reagents were used as received unless otherwise stated.…”

“…Preparation of [ 11 C]CH 3 I and subsequent 11 C-methylation were carried out automatically using the synthetic apparatus for 11 C-labeled compounds described in our previous reports. 15 All reagents were used as received unless otherwise stated.…”

“…Preparation of [ 11 C]CH 3 I and subsequent 11 C-methylation of 3a to [ 11 C] CBA were achieved automatically using specially designed equipment. 15 The [ 11 C]CH 3 I prepared was trapped in anhydrous DMF (250 μl) containing the free base of 3a (0.7 mg, 2.53 μmol) and NaH (11.4 μl, 1 M in DMF) at −15 to −20°C. The reaction vessel was heated to 30°C and incubated for 3 minutes.…”