Effect of central administration of phencyclidine on plasma concentrations of luteinizing hormone

Previous research has demonstrated that excitatory amino acids acting at N-methyl-D-aspartate (NMDA) receptors stimulate the release of luteinizing hormone (LH). Castration also elevates LH, an effect that may also involve NMDA receptors since the specific NMDA antagonist, DL-2-amino-5-phosphonopentanoic acid (AP5), antagonizes this action. Since PCP antagonizes a variety of actions of NMDA agonists, we hypothesized that it would diminish the ability of glutamate, homocysteic acid and castration to elevate LH. Our data support this hypothesis.