Phencyclidine receptors in rat brain cortex.
The binding of [3H]phencyclidine (PCP) to receptors in rat brain cortex has been studied. Two receptors have been detected, a high affinity receptor site with a KD of 23.5 +/- 7.4 nM and a low affinity site with a KD of 7.6 +/- 1.8 microM. The binding of [3H]PCP to its receptors was pH and temperature dependent and was destroyed by heat-denaturation. The binding of [3H]PCP was inhibited by compounds which produce PCP-like behavioral effects including dexoxadrol, etoxadrol and ketamine as well as a novel series of benz(f)isoquinolines. The low affinity site was blocked by PCP, etoxadrol and (+)-SKF-10,047 but not morphine or leu-enkephalin, suggesting that it also represents a specific PCP site. Stereoselective displacement of PCP at the high affinity receptor was observed with the isomers of cyclazocine, cyclorphan, SKF-10,047 and dioxadrol (dexoxadrol and levoxadrol). Naloxone, 4,5,6,7-tetrahydroisoxazolo(S,4-C)pyridin-3-ol (THIP) hydrate and haloperidol inhibited binding poorly (Ki greater than 1 microM), suggesting that these compounds do not interact significantly with the high affinity PCP receptor in vivo. The affinity of ligands for the phencyclidine receptor was highly correlated (r = 0.714, P less than 0.01) with their potency to produce catalepsy in pigeons.
D000818:Animals; D001667:Binding, Competitive; D002375:Catalepsy / Q000503:physiopathology; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D010856:Columbidae; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008297:Male; D010622:Phencyclidine / Q000378:metabolism* / Q000633:toxicity; D051381:Rats; D011919:Rats, Inbred Strains; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D017478:Receptors, Phencyclidine
D017981:Receptors, Neurotransmitter; D017478:Receptors, Phencyclidine; D010622:Phencyclidine