T. Mochizuki et al., A SIMPLE PROBE MEASURES THE PHARMACOKINETICS OF [I-125] RTI-55 IN MOUSE-BRAIN IN-VIVO, European journal of pharmacology, 338(1), 1997, pp. 17-23
A simple external radiation detector system was used to assess brain d
opamine and serotonin transporters in mice in vivo using [I-125]RTI-55
. The results were compared to ex vivo dissection data. Methyl 3 beta-
(4-iodophenyl) tropane-2 beta-carboxic acid methyl ester (RTI-55 or be
ta-CIT), a high-affinity cocaine antagonist, binds to presynaptic dopa
mine and serotonin transporters in the brain. Radiotracer accumulation
increased for the first 150 min after intravenous injection and their
remained constant. When unlabeled RTI-55 was injected, either before
or 60 min after radiotracer administration a significant decrease in t
racer accumulation was observed [I-125]RTI-55 binding was also displac
ed by blocking doses of phenyl)methoxy]ethyl]-4-[3-phenylpropyl]pipera
zine dihydrochloride (GBR 12909) and paroxetine. The results were simi
lar to the ex vivo dissection data. The results demonstrate the feasib
ility of using the probe detector system to study the presynaptic tran
sporter system in vivo in the mouse brain. The technique is applicable
to other cerebral neurotransmitter systems. (C) 1997 Elsevier Science
B.V.