title: [Ligands of glutamate and dopamine receptors evenly labeled with hydrogen isotopes].
abstract: A reaction of high-temperature solid-phase catalytic isotope exchange (HSCIE) was studied for the preparation of tritium- and deuterium-labeled ligands of glutamate and dopamine receptors. Tritium-labeled (5S,10R)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclopenten-5,10-imine ([G-(3)H]MK-801) and R(+)-7-hydroxy-N,N-di-n-propyl-2-aminotetraline ([G-(3)H]-7-OH-DPAT) were obtained with a specific activity of 210 and 120 Ci/mol, respectively. The isotopomeric distribution of deuterium-labeled ligands was studied using time-of-flight mass-spectrometer MX 5310 (ESI-o-TOF) with electrospray and orthogonal ion injection. Mean deuterium incorporation per ligand molecule was 11.09 and 3.21 atoms for [G-(2)H]MK-801 and [G-(2)H]-7-OH-DPAT, respectively. The isotope label was shown to be distributed all over the ligand molecule. The radioreceptor binding of tritium-labeled ligands [G-(3)H]MK-801 and [G-(3)H]-7-OH-DPAT was analyzed using the brain structure of Vistar rats. It was demonstrated that [G-(3)H]MK-801 specifically binds to hippocampus membranes with K(d) 8.3 +/- 1.4 nM, B(max) being 3345 +/- 300 fmol/mg protein. The [G-(3)H]-7-OH-DPAT ligand specifically binds to rat striatum membranes with K(d) 10.01 +/- 0.91 nM and B(max) 125 +/- 4.5 fmol/mg protein. It was concluded that the HSCIE reaction can be used for the preparation of highly tritium-labeled (+)-MK-801 and 7-OH-DPAT with retention of their physiological activities.
authors.affiliation: Institute of Molecular Genetics, Russian Academy of Sciences, pl. Kurchatova 2, Moscow, 123182 Russia. zolya@img.ras.ru
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Zolotarev
authors.forename: Iu Iu
authors.initials: IuIu
authors.lastname: Firstova
authors.forename: D A
authors.initials: DA
authors.lastname: Abaimov
authors.forename: A K
authors.initials: AK
authors.lastname: Dadaian
authors.forename: V S
authors.initials: VS
authors.lastname: Kosik
authors.forename: A V
authors.initials: AV
authors.lastname: Novikov
authors.forename: N V
authors.initials: NV
authors.lastname: Krasnov
authors.forename: B V
authors.initials: BV
authors.lastname: Vas'kovskiĭ
authors.forename: I V
authors.initials: IV
authors.lastname: Nazimov
authors.forename: G I
authors.initials: GI
authors.lastname: Kovalev
authors.forename: N F
authors.initials: NF
authors.lastname: Miasoedov
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D003903:Deuterium; D016291:Dizocilpine Maleate / Q000737:chemistry* / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism; D066298:In Vitro Techniques; D007553:Isotope Labeling; D008024:Ligands; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011954:Receptors, Dopamine / Q000378:metabolism*; D017470:Receptors, Glutamate / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D013764:Tetrahydronaphthalenes / Q000737:chemistry* / Q000378:metabolism; D014316:Tritium
chemical_list: D008024:Ligands; D011954:Receptors, Dopamine; D017470:Receptors, Glutamate; D013764:Tetrahydronaphthalenes; D014316:Tritium; D016291:Dizocilpine Maleate; D003903:Deuterium; C031349:7-hydroxy-2-N,N-dipropylaminotetralin