Skip to main content
eScholarship
Open Access Publications from the University of California

Evaluation of18F-nifene binding to α4β2 nicotinic receptors in the rat brain using microPET imaging

  • Author(s): Kant, R
  • Constantinescu, CC
  • Parekh, P
  • Pandey, SK
  • Pan, ML
  • Easwaramoorthy, B
  • Mukherjee, J
  • et al.
Abstract

MicroPET imaging studies using18F-nifene, a new positron emission tomography (PET) radiotracer for nicotinic acetylcholinergic receptors (nAChR) α4β2 receptors in rats, have been carried out. Rats were imaged for 90 min after intravenous injection of18F-nifene (0.8 to 1 mCi), and binding potential (BPND) was measured.18F-Nifene binding to thalamic and extrathalamic brain regions was consistent with the α4β2 nAChR distribution in the rat brain. Using the cerebellum as a reference, the values for the thalamus varied less than 5% (BPND= 1.30, n = 3), confirming reproducibility of18F-nifene binding.18F-Nifene microPET imaging was also used to evaluate effects of nicotine in a group of Sprague-Dawley rats under isoflurane anesthesia. Nicotine challenge postadministration of18F-nifene demonstrated reversibility of18F-nifene binding in vivo. For α4β2 nAChR receptor occupancy (nAChROCC), various doses of nicotine (0, 0.02, 0.1, 0.25, and 0.50 mg/kg nicotine free base) 15 min prior to18F-nifene were administered. Low-dose nicotine (0.02 mg) reached > 80% nAChROCCwhile at higher doses (0.25 mg) > 90% nAChROCCwas measured. The small amount of18F-nifene binding with reference to the cerebellum affects an accurate evaluation of nAChROCC. Efforts are underway to identify alternate reference regions for18F-nifene microPET studies in rodents. © 2011 Kant et al.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View