title: Correlative single photon emission computed tomography imaging of [123I]altropane binding in the rat model of Parkinson's.
abstract: BACKGROUND
  This study used the dopamine transporter (DAT) probe, [(123)I]-2β-carbomethoxy-3β-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane ([(123)I]altropane), to assess the DAT levels in the 6-hydroxydopamine rat model of Parkinson's disease. We sought to assess if the right to left [(123)I]altropane striatal ratios correlated with dopamine content in the striatum and substantia nigra and with behavioural outcomes.
  
  
  METHODS
  [(123)I]altropane images taken pre- and postlesion were acquired before and after the transplantation of neural stem/progenitor cells. The images obtained using [(123)I]altropane and single photon emission computed tomography (SPECT) were compared with specific behavioural tests and the dopamine content assessed by high-performance liquid chromatography.
  
  
  RESULTS
  [(123)I]altropane binding correlated with the content of dopamine in the striatum; however, [(123)I]altropane binding did not correlate with the dopamine content in the substantia nigra. There was a significant correlation of altropane ratios with the cylinder test and the postural instability test, but not with amphetamine rotations. The low coefficient of determination (r(2)) for these correlations indicated that [(123)I]altropane SPECT was not a good predictor of behavioural outcomes.
  
  
  CONCLUSIONS
  Our data reveal that [(123)I]altropane predicts the integrity of the striatal dopamine nerve terminals, but does not predict the integrity of the nigrostriatal system. [(123)I]altropane could be a useful marker to measure dopamine content in cell replacement therapies; however, it would not be able to evaluate outcomes for neuroprotective strategies.
authors: Department of Pathology and Molecular Medicine, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.
authors: Jacqueline A
authors: JA
authors: Gleave
authors: Troy H
authors: TH
authors: Farncombe
authors: Chantal
authors: C
authors: Saab
authors: Laurie C
authors: LC
authors: Doering
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015415:Biomarkers / Q000378:metabolism; D003042:Cocaine / Q000031:analogs & derivatives* / Q000378:metabolism; D004195:Disease Models, Animal; D004298:Dopamine / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D007457:Iodine Radioisotopes; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D058953:Neural Stem Cells / Q000637:transplantation; D016627:Oxidopamine / Q000494:pharmacology; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D033581:Stem Cell Transplantation; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015415:Biomarkers; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; C102282:N-iodoallyl-2-carbomethoxy-3-(4-fluorophenyl)tropane; D016627:Oxidopamine; D003042:Cocaine; D004298:Dopamine