[125/123I]IPH: a radioiodinated analog of epibatidine for in vivo studies of nicotinic acetylcholine receptors.
JL Musachio, VL Villemagne, U Scheffel, M Stathis, P Finley, A Horti, ED London, RF Dannals
Synapse | Published : 1997
Tomographic imaging of central nicotinic acetylcholine receptors (nAChRs) via single photon emission computed tomography (SPECT) has been hampered by the lack of a radioligand with suitable in vivo binding characteristics. Therefore, a novel analog of epibatidine, (+/-)-exo-2-(2-iodo-5-pyridyl)-7-azabicyclo[2.2.1]heptane (IPH), labeled with [(125)I] or [(123)I] was evaluated as an in vivo marker of central nicotinic acetylcholine receptors (nAChRs). [(125)I]IPH showed substantial brain penetration (4.2% of the injected dose at 30 min) and a cerebral biodistribution in mice consistent with the in vivo labeling of nAChRs (% injected dose/gram of thalamus, superior colliculi >> cerebellum). [(1..View full abstract