title: Evaluation of 18F-BCPP-EF for mitochondrial complex 1 imaging in the brain of conscious monkeys using PET.
abstract: OBJECTIVE
  We have reported on the development of a novel PET probe, (18)F-2-tert-butyl-4-chloro-5-{6-[2-(2-fluoroethoxy)-ethoxy]-pyridin-3-ylmethoxy}-2H-pyridazin-3-one ((18)F-BCPP-EF), for quantitative imaging of mitochondrial complex 1 (MC-1) activity in the brain of the living rat. For clinical application in humans, translational research in the monkey was conducted.
  
  
  METHODS
  PET measurements with (18)F-BCPP-EF were performed in young and old monkeys (Macaca mulatta) in a conscious state with arterial blood sampling. The binding specificity of (18)F-BCPP-EF was evaluated with rotenone, a specific MC-1 inhibitor, in young animals. The binding (total distribution volume, V T) of (18)F-BCPP-EF was calculated using Logan graphical analysis, and one-tissue compartment model (1-TC) and two-tissue compartment model (2-TC) analyses using a metabolite-corrected plasma input function.
  
  
  RESULTS
  F-BCPP-EF was rapidly taken up into the brain just after intravenous injection, peaked between 10 and 20 min after injection, and was then gradually eliminated. The 2-TC analysis provided a better fit than the 1-TC analysis, and the V T values from the 2-TC analysis correlated well with those from the Logan plot. With predosing with rotenone, (18)F-BCPP-EF showed a higher uptake peak in the brain, followed by more rapid elimination thereafter than in the vehicle condition, resulting in significant reductions in 2-TC V T values in all regions. In old animals, the kinetics of (18)F-BCPP-EF were slightly slower with lower peak levels than in young animals, resulting age-related reductions in (18)F-BCPP-EF binding in all brain regions.
  
  
  CONCLUSIONS
  The present study demonstrated that (18)F-BCPP-EF may be a potential PET probe for quantitative imaging MC-1 activity in the living brain using PET.
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita, Hamamatsu, Shizuoka, 434-8601, Japan, tsukada0412@nifty.com.
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsukada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohba
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Kanazawa
authors.forename: Takeharu
authors.initials: T
authors.lastname: Kakiuchi
authors.forename: Norihiro
authors.initials: N
authors.lastname: Harada
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000254:growth & development / Q000378:metabolism; D042967:Electron Transport Complex I / Q000378:metabolism*; D008253:Macaca mulatta; D049268:Positron-Emission Tomography; D011724:Pyridazines / Q000493:pharmacokinetics* / Q000494:pharmacology; D011725:Pyridines / Q000493:pharmacokinetics* / Q000494:pharmacology; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics* / Q000494:pharmacology; D014018:Tissue Distribution
chemical_list: C588084:2-tert-butyl-4-chloro-5-(6-(2-(2-fluoroethoxy)ethoxy)pyridin-3-ylmethoxy)-2H-pyridazin-3-one; D011724:Pyridazines; D011725:Pyridines; D019275:Radiopharmaceuticals; D042967:Electron Transport Complex I