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.
Published Web Locationhttps://doi.org/10.1186/2191-219X-1-6
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.