Comparison of [3H] phencyclidine ([3H] PCP) and [3H] N-[1-(2-thienyl) cyclohexyl] piperidine ([3H] TCP) binding properties to rat and human brain membranes.
The investigation of [3H] PCP and [3H] TCP binding properties to rat cerebrum and cerebellum resulted in the demonstration of multiple binding sites for the two drugs. In the two tissue preparations PCP had a lower affinity than TCP. In membranes from the cerebrum an equal number of high affinity binding sites were present for [3H] PCP and [3H] TCP. However, low affinity binding sites were two times more numerous for [3H] PCP than for [3H] TCP. In the cerebellum, the number of high and low affinity sites labeled by the two radioligands was identical, but the number of high affinity sites was about 7 fold lower than in the cerebrum. Taken together these results may indicate that in the cerebrum [3H] PCP labels other sites than NMDA/PCP receptor(s), maybe sigma receptors and/or the dopamine uptake complex. In human cerebral cortex samples [3H] TCP also bound to two different sites. The number of high and low affinity sites were 12 and 3 times, respectively, less abundant than in the rat cerebrum. Low affinity sites were of higher affinity (5 times) than corresponding sites in the rat brain. In the human cerebellum [3H] TCP binding parameters were identical to those measured in the same region in the rat.
Vignon
J
J
CNRS UPR 41, INSERM U 249, Ecole Nationale Supérieure de Chimie, Montpellier, France.
Chaudieu
I
I
Allaoua
H
H
Journod
L
L
Javoy-Agid
F
F
Agid
Y
Y
Chicheportiche
R
R
D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000378:metabolism; D010622:Phencyclidine / Q000031:analogs & derivatives* / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
C012058:tenocyclidine; D010622:Phencyclidine