Dual SPECT of dopamine system using [99mTc]TRODAT-1 and [123I]IBZM in normal and 6-OHDA-lesioned formosan rock monkeys.
Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a severe loss of the dopaminergic neurons in the substantia nigra pars compacta. In this study, we evaluated pre- and post-synaptic binding sites of the dopamine system in three normal and one parkinsonian monkeys using simultaneous [99mTc]TRODAT-1 and [123I]IBZM imaging. The parkinsonian monkey was induced by injecting 6-hydroxydopamine (6-OHDA) bilaterally into the medial forebrain bundle under MRI guidance. [99mTc]TRODAT-1 (targeting dopamine transporters) and [123I]IBZM (targeting D(2)/D(3) receptors) were administered almost simultaneously and the SPECT images were acquired over 4 h using a dual-headed gamma camera equipped with ultra-high resolution fan-beam collimators. Data were obtained using energy window of 15% centered on 140 keV for 99mTc in conjunction with 10% asymmetric energy window in a lower bound at 159 keV for 123I. Single SPECT studies of [99mTc]TRODAT-1 and [123I]IBZM were also performed. We found a comparable image quality and uptake ratios between single- and dual-isotope studies. There are higher TRODAT-1 uptakes in the control monkeys than the 6-OHDA-lesioned monkey. The uptake of [123I] IBZM showed no significant difference between controls and 6-OHDA-lesioned monkey. Our results suggest that dual isotope imaging using [99mTc]TRODAT-1 and [123I]IBZM may be a useful means in evaluating the changes of both pre- and post-synaptic dopamine system in a primate model of parkinsonism.
Ma
Kuo-Hsing
KH
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, Republic of China.
Huang
Wen-Sheng
WS
Chen
Chien-Hsing
CH
Lin
Shin-Zong
SZ
Wey
Shiaw-Pyng
SP
Ting
Gann
G
Wang
Shwun-De
SD
Liu
Hwan-Wun
HW
Liu
Jiang-Chuan
JC
D000818:Animals; D001549:Benzamides / Q000493:pharmacokinetics*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D008251:Macaca; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D016627:Oxidopamine / Q000008:administration & dosage; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000000981:diagnostic imaging / Q000378:metabolism*; D011237:Predictive Value of Tests; D011759:Pyrrolidines / Q000493:pharmacokinetics*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012016:Reference Values; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014326:Tropanes / Q000493:pharmacokinetics*
D001549:Benzamides; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide; D016627:Oxidopamine; D004298:Dopamine