TY - JOUR
T1 - An electrophilic affinity ligand based on (+)-MK801 distinguishes PCP site 1 from PCP site 2
AU - Akunne, Hyacinth C.
AU - Monn, J. A.
AU - Thurkauf, Andrew
AU - Jacobson, Arthur E.
AU - Rice, Kenner C.
AU - Linders, Joannes T.M.
AU - Jiang, Q.
AU - Porreca, F.
AU - Rothman, Richard B.
PY - 1994/4
Y1 - 1994/4
N2 - The electrophilic affinity ligand, (+)-3-isothiocyanato-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine hydrochloride {(+)-MK801-NCS} was characterized for its ability to acylate phencyclidine (PCP) and sigma binding sites in vivo. Initial studies, conducted with mouse brain membranes, characterized the binding sites labeled by [3H]1-[1-(2-thienyl)cyclohexyl]piperidine ([3H]TCP). The Kd values of [3H]TCP for PCP site 1 (MK801-sensitive) and PCP site 2 (MK801-insensitive) were 12 nM and 68 nM, with Bmax values of 1442 and 734 fmol/mg protein, respectively. Mice were sacrificed 18-24 hours following intracerebroventricular administration of the acylator. The administration of (+)-MK801-NCS increased [3H]TCP binding to site 2, but not to site. 1. Although (+)-MK801-NCS decreased [3H](+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d; cbcyclohepten-5,10-imine maleate ([3H](+)-MK801) binding to site 1, it had no effect on [3H]TCP binding to site 1. Viewed collectively with other published data, these data support the hypothesis that PCP sites 1 and 2 are distinct binding sites, and that [3H]TCP and [3H](+)-MK801 label different domains of the PCP binding site associated with the NMDA receptor.
AB - The electrophilic affinity ligand, (+)-3-isothiocyanato-5-methyl-10,11-dihydro-5H-dibenzo[a,d] cyclohepten-5,10-imine hydrochloride {(+)-MK801-NCS} was characterized for its ability to acylate phencyclidine (PCP) and sigma binding sites in vivo. Initial studies, conducted with mouse brain membranes, characterized the binding sites labeled by [3H]1-[1-(2-thienyl)cyclohexyl]piperidine ([3H]TCP). The Kd values of [3H]TCP for PCP site 1 (MK801-sensitive) and PCP site 2 (MK801-insensitive) were 12 nM and 68 nM, with Bmax values of 1442 and 734 fmol/mg protein, respectively. Mice were sacrificed 18-24 hours following intracerebroventricular administration of the acylator. The administration of (+)-MK801-NCS increased [3H]TCP binding to site 2, but not to site. 1. Although (+)-MK801-NCS decreased [3H](+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d; cbcyclohepten-5,10-imine maleate ([3H](+)-MK801) binding to site 1, it had no effect on [3H]TCP binding to site 1. Viewed collectively with other published data, these data support the hypothesis that PCP sites 1 and 2 are distinct binding sites, and that [3H]TCP and [3H](+)-MK801 label different domains of the PCP binding site associated with the NMDA receptor.
KW - (+)-MK801
KW - 1,3-di(2-tolyl)guanidine
KW - N-methyl-D-aspartate
KW - PCP
KW - affinity ligands
KW - sigma receptors
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U2 - 10.1007/BF00967314
DO - 10.1007/BF00967314
M3 - Article
C2 - 8065494
AN - SCOPUS:0027982099
SN - 0364-3190
VL - 19
SP - 385
EP - 389
JO - Neurochemical Research
JF - Neurochemical Research
IS - 4
ER -