Studies on Quantitative Analysis of Dopamine Receptor Function in Brain.
| Project/Area Number |
08457242
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Radiation science
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| Research Institution | Fukui Medcal School |
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Principal Investigator |
YONEKURA Yoshiharu Fukui Meidical School, Biomedical Imaging Research Center, Professor, 高エネルギー医学研究センター, 教授 (60135572)
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| Co-Investigator(Kenkyū-buntansha) |
SADATO Norihiro Fukui Medical School, Biomedical Imaging Research Center, Lecturer, 高エネルギー医学研究センター, 講師 (00273003)
FUJIBAYASHI Yasuhisa Kyoto University, Faculty of Pharmaceutical Sciences, Associate Professor, 薬学部, 助教授 (50165411)
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| Project Period (FY) |
1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 1996: ¥5,200,000 (Direct Cost: ¥5,200,000)
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| Keywords | Neuroreceptor / dopamine / image analysis / SPECT / brain function |
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| Research Abstract |
In order to establish the methods for quantitative measurement of dopamine receptors in human brain, we have examined the various approaches based on the mathematical modeling of the kinetic behavior of the radioligands for development of simple methods to be used for clinical studies. The study was performed with single photon emission computed tomography (SPECT) using two iodine-123 labeled radioligands which bind to dopamine D2 receptors, 2'-iodospiperone (2'-ISP) and iodobenzofuran (IBF). Following the intravenous injection to the normal subjects, serial SPECT imaging was performed with intermittent blood sampling for the analysis of blood metablites. Both 2'-ISP and IBF showed selective and reversible binding to the striatal dopamine receptors. In 2'-ISP,the striatal uptake reached maximum value at one hour after the administration, and decreased gradually thereafter. Striatum to cerebral cortex (Str/Cx) ratio obtained as a simple quantitative index of receptor binding revealed nearly constant between 2 and 4 hours, suggesting that this index can be used as a simple parameter to evaluate the receptor binding in clinical studies. IBF showed more rapid uptake in the striatum and faster clearance from the nonspecific binding site, resulting in the greater valus for Str/Cx ratio than 2'-ISP.Binding potential in the striatum calculated by the compartment analysis of IBF using the serial SPECT data and the arterial blood activity demonstrated a good agreement with Str/Cx ratio, but the time dependent changes in Str/Cx ratio was noted.
The results suggested that the ratio of specific binding to nonspecific binding during the pseudo-equilibrium state may be of some problem for the time dependent changes of the value although it can be used noninvasively as a simple parameter in clinical settings.
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Report
(2 results)
Research Products
(3 results)
