Further characterization of [3H]ifenprodil binding in rat brain

Characterisation of N‐Methyl‐D‐Aspartate Receptor‐Specific [3H]Ifenprodil Binding to Recombinant Human NR1a/NR2B Receptors Compared with Native Receptors in Rodent Brain Membranes

“…3) were similar to those previously obtained using [ 3 H]MK-801 binding in vivo (Murray et al, 2000). (Schoemaker et al, 1990;Hashimoto et al, 1994;Coughenour and Cordon, 1997). However, in these earlier studies, shallow Hill slopes were often indicated, suggesting the presence of additional binding sites unrelated to the NMDA receptor, potentially influencing the data.…”

“…K i values were calculated using the Cheng-Prusoff equation (Cheng and Prusoff, 1973): (Schoemaker et al, 1990;Hashimoto et al, 1994;Coughenour and Cordon, 1997 Haloperidol was found to be a more potent site ligand (data not shown) but was not appropriate to use as a non-NMDA receptor blocker because it is also an NR1/NR2B-selective NMDA antagonist (Ilyin et al, 1996). Therefore, to ensure NMDA receptor-specific binding, all further experiments were performed in the presence of maximal concentrations of R(ϩ)-3-PPP (100 M), GBR-12909 (1 M), and GBR-12935 (1 M), while also using the NMDA receptor-selective antagonist (Ϯ)-CP-101,606 to define nonspecific binding rather than ifenprodil, which has been used in all previous studies of this type.…”

“…As previous work showed that [ 3 H]ifenprodil bound preferentially to receptors at 37°C and to NMDA receptors at 4°C (Hashimoto et al, 1994), all experiments were performed at 4°C. Electrophysiological experiments have shown ifenprodil inhibition to be less effective at alkaline pH (Pahk and Williams, 1997;Mott et al, 1998); therefore, using saturation analyses, [ 3 H]ifenprodil binding to NR1a/NR2B cell membranes was compared at pH 6.0, 7.0, and 8.0.…”

Lamina-Specific Abnormalities of NMDA Receptor-Associated Postsynaptic Protein Transcripts in the Prefrontal Cortex in Schizophrenia and Bipolar Disorder

“…Receptor autoradiography was carried out under saturating conditions of ligand using assays that have been previously described in detail (Huettner and Bean, 1988;Ransom and Stec, 1988;Sills et al, 1991;Hashimoto et al, 1994;Baron et al, 1996;Siegel et al, 1996;White and Vogel, 1996;Healy et al, 1998;Healy and Meador-Woodruff, 1999;Ibrahim et al, 2000a, b …”

Synthesis of 11C-Labelled Bis(phenylalkyl)amines and Their in Vitro and in Vivo Binding Properties in Rodent and Monkey Brains

“…These orders of inhibitory effects by polyamines are similar to those reported for the inhibition of [ 3 H]CP-101,606 and [ 3 H]ifenprodil. [30][31][32][33] Although the highaffinity ifenprodil site is supposed to be located on the NR2B subunit, a low-affinity ifenprodil site has also been proposed, through which ifenprodil acts as a weak open-channel blocker. 34) Divalent cations also inhibited the [ 11 C]2 at concentrations of 100 mM, whereas no inhibition of [ 11 C]3 was observed with these ligands at the same concentrations, suggesting that the binding of [ 11 C]2 was also occurring at the serotonin recognition sites.…”