Ketamine displaces the novel NMDA receptor SPET probe [(123)I]CNS-1261 in humans in vivo

Nucl Med Biol. 2006 Feb;33(2):239-43. doi: 10.1016/j.nucmedbio.2005.12.001.

Abstract

[(123)I]CNS-1261 [N-(1-naphthyl)-N'-(3-iodophenyl)-N-methylguanidine] is a high-affinity SPET ligand with selectivity for the intra-channel PCP/ketamine/MK-801 site of the N-methyl-d-aspartate (NMDA) receptor. This study evaluated the effects of ketamine (a specific competitor for the intra-channel PCP/ketamine/MK-801 site) on [(123)I]CNS-1261 binding to NMDA receptors in vivo. Ten healthy volunteers underwent 2 bolus-plus-infusion [(123)I]CNS-1261 scans, one during placebo and the other during a ketamine challenge. Ketamine administration led to a significant decrease in [(123)I]CNS-1261 V(T) in most of the brain regions examined (P<.05). [(123)I]CNS-1261 appears to be a specific ligand in vivo for the intra-channel PCP/ketamine/MK-801 NMDA binding site.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Cross-Over Studies
  • Guanidines / pharmacokinetics*
  • Humans
  • Iodine Radioisotopes / pharmacokinetics
  • Ketamine / administration & dosage*
  • Ketamine / pharmacokinetics*
  • Male
  • Metabolic Clearance Rate
  • Molecular Probe Techniques
  • Placebo Effect
  • Radiopharmaceuticals / pharmacokinetics
  • Receptors, N-Methyl-D-Aspartate / metabolism*
  • Single-Blind Method
  • Tissue Distribution
  • Tomography, Emission-Computed, Single-Photon / methods*

Substances

  • CNS 1261
  • Guanidines
  • Iodine Radioisotopes
  • Radiopharmaceuticals
  • Receptors, N-Methyl-D-Aspartate
  • Ketamine