Evaluation of [11C]RTI-121 as a selective radioligand for PET studies of the dopamine transporter

Nucl Med Biol. 1996 Apr;23(3):377-84. doi: 10.1016/0969-8051(96)00019-4.

Abstract

The cocaine analogue RTI-121 (3 beta-(4-iodophenyl)tropane-2 beta-carboxylic acid isopropyl ester), when labeled with carbon-11, was evaluated in rats as a potential PET ligand for the dopamine transporter. The compound gave in vivo striatum:cerebellum ratios that were similar to those obtained with the related ligand [11C]RTI-55 (2 beta-(4-iodophenyl)tropane-2 beta-carboxylic acid methyl ester) but showed a much greater selectivity for the dopamine compared with the 5-HT uptake site. The results indicate that [11C]RTI-121 could be used in preference to [11C]RTI-55 in man. Experimentally, [11C]RTI-121 has potential in the quantification of dopamine terminal function in rat models of disease, using a combination of autoradiography, postmortem sampling, and in vivo tomography.

MeSH terms

  • Animals
  • Biotransformation
  • Blood Proteins / metabolism
  • Brain / diagnostic imaging*
  • Brain / metabolism*
  • Carbon Radioisotopes*
  • Carrier Proteins / analysis
  • Carrier Proteins / metabolism*
  • Cerebellum / metabolism
  • Cocaine / analogs & derivatives*
  • Cocaine / metabolism
  • Cocaine / pharmacokinetics
  • Corpus Striatum / metabolism
  • Dopamine / metabolism
  • Dopamine Plasma Membrane Transport Proteins
  • Male
  • Membrane Glycoproteins*
  • Membrane Transport Proteins*
  • Nerve Tissue Proteins*
  • Radioligand Assay
  • Rats
  • Rats, Sprague-Dawley
  • Tissue Distribution
  • Tomography, Emission-Computed / methods*

Substances

  • Blood Proteins
  • Carbon Radioisotopes
  • Carrier Proteins
  • Dopamine Plasma Membrane Transport Proteins
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Nerve Tissue Proteins
  • RTI 121
  • Cocaine
  • Dopamine