Positron emission tomography and ex vivo and in vitro autoradiography studies on dopamine D2-like receptor degeneration in the quinolinic acid-lesioned rat striatum: comparison of [11C]raclopride, [11C]nemonapride and [11C]N-methylspiperone.
With [11C]raclopride,[11C]nemonapride and [11C]N-methylspiperone, degeneration of dopamine D2-like receptors in the unilaterally quinolinic acid-lesioned rats was evaluated by positron emission tomography (PET) and ex vivo and in vitro autoradiography. PET showed a decreased uptake of [11C]raclopride in the lesioned striatum, but an increased uptake of [11C]nemonapride and [11C]N-methylspiperone despite a decreased binding in vitro. Ex vivo autoradiography showed an increased accumulation of the three ligands in the cortical region overlying the injured striatum, probably enlarging PET signals. PET has the limited potential for evaluating the receptor degeneration in the present animal model.
Ishiwata
Kiichi
K
Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, 1-1 Naka-cho, Itabashi-ku, 172-0022, Tokyo, Japan. ishiwata@pet.tmig.or.jp
Ogi
Nobuo
N
Hayakawa
Nobutaka
N
Umegaki
Hiroyuki
H
Nagaoka
Tsukasa
T
Oda
Keiichi
K
Toyama
Hinako
H
Endo
Kazutoyo
K
Tanaka
Akira
A
Senda
Michio
M
D000818:Animals; D001345:Autoradiography; D001549:Benzamides / Q000493:pharmacokinetics*; D018492:Dopamine Antagonists / Q000493:pharmacokinetics*; D005947:Glucose / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D017072:Neostriatum / Q000187:drug effects / Q000378:metabolism*; D009498:Neurotoxins / Q000633:toxicity*; D017378:Quinolinic Acid / Q000633:toxicity*; D020891:Raclopride / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000187:drug effects / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism; D013134:Spiperone / Q000031:analogs & derivatives* / Q000493:pharmacokinetics*; D014055:Tomography, Emission-Computed / Q000379:methods*
D001549:Benzamides; D018492:Dopamine Antagonists; D009498:Neurotoxins; D019275:Radiopharmaceuticals; D017448:Receptors, Dopamine D2; D011963:Receptors, GABA-A; D020891:Raclopride; D013134:Spiperone; C039167:3-N-methylspiperone; D017378:Quinolinic Acid; D005947:Glucose; C030265:nemonapride