(+)-[3H]3-(3-hydroxyphenyl)-N-(1-propyl)-piperidine binding to sigma receptors in mouse brain in vivo.

Binding of i.v. administered (+)-[3H]3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ([3H]3-PPP) in the brain of intact mice is antagonized dose responsively by sigma receptor ligands. The correlation of potencies for inhibition of binding in vivo and in vitro indicates that sigma receptors in mouse brain are labeled in vivo by i.v. [3H]3-PPP. 3-PPPP, the N-phenylpropyl derivative of norpropyl-3-PPP exhibits very high affinity for sigma receptors in vitro and in vivo.