6-[18F]fluoro-A-85380, a novel radioligand for in vivo imaging of central nicotinic acetylcholine receptors

Life Sci. 2000 Jun 16;67(4):463-9. doi: 10.1016/s0024-3205(00)00635-4.

Abstract

A novel positron emission tomography (PET) radiotracer, 6-[18F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (6-[18F]fluoro-A-85380, 6-[18F]FA) was synthesized by a no-carrier-added fluorination. In vitro 6-[18F]FA bound to nicotinic acetylcholine receptors (nAChRs), with very high affinity (Kd 28 pM). In PET studies, 6-[18F]FA specifically labeled central nAChRs in the brain of the Rhesus monkey and demonstrated highest levels of accumulation of radioactivity in brain regions enriched with the alpha4beta2 subtype of nAChR. 6-[18F]FA exhibited a target-to-non-target ratio (estimated as radioactivity in the thalamus to that in the cerebellum) of binding in primate brain similar to that previously determined for a labeled analog of epibatidine, [18F]FPH. In contrast to [18F]FPH, the novel tracer is expected to exhibit substantially less toxicity. Thus, the novel radioligand, 6-[18F]FA, appears to be a suitable candidate for imaging nAChRs in human brain.

MeSH terms

  • Animals
  • Azetidines* / chemical synthesis
  • Brain / diagnostic imaging*
  • Brain / metabolism
  • Chromatography, High Pressure Liquid
  • Fluorine Radioisotopes*
  • Macaca mulatta
  • Male
  • Rats
  • Rats, Inbred F344
  • Receptors, Nicotinic / analysis*
  • Tissue Distribution
  • Tomography, Emission-Computed*

Substances

  • A 85380
  • Azetidines
  • Fluorine Radioisotopes
  • Receptors, Nicotinic