Phencyclidine receptors in porcine cerebral arteries

A specific, saturable, reversible, and selective binding site with Kd = 87 +/- 33 nmol/L, Bmax = 0.78 +/- 0.11 pmol/mg protein was detected in the binding of [3H] phencyclidine (PCP) to porcine cerebral blood vessels. Only ligands of PCP/sigma series were able to bind to the PCP receptors. [3H]PCP bound to its receptors was not displaced by etorphine or norepinephrine 0.1 mmol/L. A specific [3H]PCP binding site was found in porcine brain with Kd = 75 +/- 34 nmol/L, Bmax = 0.61 +/- 0.23 pmol/mg protein. Bioassay in vitro showed PCP enhanced the perfusion pressure of porcine cerebral blood vessels in a dose-dependent manner. This study provides direct evidence for PCP receptors on cerebral blood vessels, and suggests that PCP may produce cerebral vasospasm via PCP receptor interaction.