Psychotomimetic opiate receptors labeled and visualized with ( )-[3H]3-(3-hydroxyphenyl)-N-(1-propyl)piperidine

Abstract

3-(3-Hydroxyphenyl)-N-(1-propyl)piperidine (3-PPP) has been proposed as a selective dopamine autoreceptor agonist in the central nervous system. This report describes the pharmacology and localization of specific high-affinity binding sites for (+)-[3H]3-PPP in brain. The drug specificity of (+)-[3H]3-PPP binding is identical to that of σ receptors, which may mediate psychotomimetic effects of some opiates. Haloperidol and the opioid derivatives, pentazocine, cyclazocine and SKF 10,047 are potent inhibitors of (+)-[3H]3-PPP binding. Stereoselectivity is exhibited for the (+) isomers of cyclazocine and SKF 10,047 at the σ site, opposite to the stereoselectivity seen at μ, δ, and κ opiate rece..