Central serotonergic S2 binding in Papio anubis measured in vivo with N-omega-[18F]fluoroethylketanserin and PET

Neurosci Lett. 1991 Feb 11;123(1):23-6. doi: 10.1016/0304-3940(91)90149-n.

Abstract

N-omega-[18F]fluoroethylketanserin ([18F]FEK), an 18F-labeled analogue of the serotonin S2 antagonist ketanserin, was evaluated for use with positron emission tomography (PET). PET imaging of a baboon brain following injection of [18F]FEK indicated that the fluorinated ligand rapidly localized in vivo within S2 receptor-rich tissues (frontal cortex/cerebellum radioactivity ratio = 2.5 after 15 min), and selective localization was retained for as long as 3 h post injection. Pretreatment with unlabeled ketanserin (15 mg/kg, i.v.) 1 h prior to [18F]FEK completely abolished selective localization of the radiotracer, whereas regional cerebral blood flow, cerebral blood volume, and the free fraction of [18F]FEK in arterial blood were unaltered. [18F]FEK has several advantages compared to previously used PET radiopharmaceuticals, and may be an excellent radioligand for non-invasive evaluation of S2 binding in vivo.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain / diagnostic imaging
  • Brain / metabolism*
  • Fluorine Radioisotopes
  • Ketanserin / analogs & derivatives*
  • Ketanserin / metabolism
  • Ketanserin / pharmacology
  • Kinetics
  • Organ Specificity
  • Papio
  • Receptors, Serotonin / metabolism*
  • Tomography, Emission-Computed

Substances

  • Fluorine Radioisotopes
  • Receptors, Serotonin
  • N-2-fluoroethylketanserin
  • Ketanserin