Characterisation of [¹¹C]PR04.MZ in Papio anubis baboon: a selective high-affinity radioligand for quantitative imaging of the dopamine transporter

Bioorg Med Chem Lett. 2012 Jan 1;22(1):679-82. doi: 10.1016/j.bmcl.2011.10.053. Epub 2011 Oct 25.

Abstract

N-(4-fluorobut-2-yn-1-yl)-2β-carbomethoxy-3β-(4'-tolyl)nortropane (PR04.MZ, 1) is a PET radioligand for the non-invasive exploration of the function of the cerebral dopamine transporter (DAT). A reliable automated process for routine production of the carbon-11 labelled analogue [(11)C]PR04.MZ ([(11)C]-1) has been developed using GMP compliant equipment. An adult female Papio anubis baboon was studied using a test-retest protocol with [(11)C]-1 in order to assess test-retest reliability, metabolism and CNS distribution profile of the tracer in non-human primates. Blood sampling was performed throughout the studies for determination of the free fraction in plasma (f(P)), plasma input functions and metabolic degradation of the radiotracer [(11)C]-1. Time-activity curves were derived for the putamen, the caudate nucleus, the ventral striatum, the midbrain and the cerebellum. Distribution volumes (V(T)) and non-displaceable binding potentials (BP(ND)) for various brain regions and the blood were obtained from kinetic modelling. [(11)C]-1 shows promising results as a selective marker of the presynaptic dopamine transporter. With the reliable visualisation of the extra-striatal dopaminergic neurons and no indication on labelled metabolites, the tracer provides excellent potential for translation into man.

Publication types

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

MeSH terms

  • Animals
  • Binding Sites
  • Brain / pathology
  • Brain Mapping / methods*
  • Carbon Isotopes / chemistry
  • Dopamine Plasma Membrane Transport Proteins / metabolism*
  • Drug Design
  • Female
  • Inhibitory Concentration 50
  • Kinetics
  • Models, Chemical
  • Papio anubis
  • Positron-Emission Tomography / methods*
  • Protein Binding
  • Protons
  • Radiopharmaceuticals / chemical synthesis
  • Radiopharmaceuticals / pharmacology*
  • Rats
  • Time Factors
  • Tropanes / chemical synthesis
  • Tropanes / pharmacology*

Substances

  • Carbon Isotopes
  • Dopamine Plasma Membrane Transport Proteins
  • PR04.MZ compound
  • Protons
  • Radiopharmaceuticals
  • Tropanes