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Tamura K, Nishii R, Tani K, Hashimoto H, Kawamura K, Zhang MR, Maeda T, Yamazaki K, Higashi T, Jinzaki M. A first-in-man study of [ 18F] FEDAC: a novel PET tracer for the 18-kDa translocator protein. Ann Nucl Med 2024; 38:264-271. [PMID: 38285284 PMCID: PMC10954948 DOI: 10.1007/s12149-023-01895-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 12/10/2023] [Indexed: 01/30/2024]
Abstract
PURPOSE N-benzyl-N-methyl-2-[7, 8-dihydro-7-(2-[18F] fluoroethyl) -8-oxo-2-phenyl-9H-purin-9-yl] acetamide ([18F] FEDAC) is a novel positron emission tomography (PET) tracer that targets the translocator protein (TSPO; 18 kDa) in the mitochondrial outer membrane, which is known to be upregulated in various diseases such as malignant tumors, neurodegenerative diseases, and neuroinflammation. This study presents the first attempt to use [18F]FEDAC PET/CT and evaluate its biodistribution as well as the systemic radiation exposure to the radiotracer in humans. MATERIALS AND METHODS Seventeen whole-body [18F]FEDAC PET/CT (injected dose, 209.1 ± 6.2 MBq) scans with a dynamic scan of the upper abdomen were performed in seven participants. Volumes of interest were assigned to each organ, and a time-activity curve was created to evaluate the biodistribution of the radiotracer. The effective dose was calculated using IDAC-Dose 2.1. RESULTS Immediately after the intravenous injection, the radiotracer accumulated significantly in the liver and was subsequently excreted into the gastrointestinal tract through the biliary tract. It also showed high levels of accumulation in the kidneys, but showed minimal migration to the urinary bladder. Thus, the liver was the principal organ that eliminated [18F] FEDAC. Accumulation in the normal brain tissue was minimal. The effective dose estimated from biodistribution in humans was 19.47 ± 1.08 µSv/MBq, and was 3.60 mSV for 185 MBq dose. CONCLUSION [18F]FEDAC PET/CT provided adequate image quality at an acceptable effective dose with no adverse effects. Therefore, [18F]FEDAC may be useful in human TSPO-PET imaging.
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Affiliation(s)
- Kentaro Tamura
- Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan.
| | - Ryuichi Nishii
- Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
- Department of Integrated Health Sciences, Graduate School of Medicine, Nagoya University, 1-1-20 Daiko Minami, Higashi-ku, Nagoya, 461-8673, Japan.
| | - Kotaro Tani
- Department of Radiation Measurement and Dose Assessment, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Hiroki Hashimoto
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Kazunori Kawamura
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Takamasa Maeda
- Department of Medical Technology, Quantum Life and Medical Science Directorate, QST Hospital, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Kana Yamazaki
- Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Tatsuya Higashi
- Department of Molecular Imaging and Theranostics, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Masahiro Jinzaki
- Department of Radiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-Ku, Tokyo, 160-8582, Japan
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Wang X, Chen C, Yan J, Xu Y, Pan D, Wang L, Yang M. Druggability of Targets for Diagnostic Radiopharmaceuticals. ACS Pharmacol Transl Sci 2023; 6:1107-1119. [PMID: 37588760 PMCID: PMC10425999 DOI: 10.1021/acsptsci.3c00081] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Indexed: 08/18/2023]
Abstract
Targets play an indispensable and pivotal role in the development of radiopharmaceuticals. However, the initial stages of drug discovery projects are often plagued by frequent failures due to inadequate information on druggability and suboptimal target selection. In this context, we aim to present a comprehensive review of the factors that influence target druggability for diagnostic radiopharmaceuticals. Specifically, we explore the crucial determinants of target specificity, abundance, localization, and positivity rate and their respective implications. Through a detailed analysis of existing protein targets, we elucidate the significance of each factor. By carefully considering and balancing these factors during the selection of targets, more efficacious and targeted radiopharmaceuticals are expected to be designed for the diagnosis of a wide range of diseases in the future.
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Affiliation(s)
- Xinyu Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Chongyang Chen
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Junjie Yan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Yuping Xu
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
| | - Donghui Pan
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Lizhen Wang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
| | - Min Yang
- NHC
Key Laboratory of Nuclear Medicine, Jiangsu Key Laboratory of Molecular
Nuclear Medicine, Jiangsu Institute of Nuclear
Medicine, Wuxi 214063, PR China
- School
of Pharmacy, Nanjing Medical University, Nanjing 211166, PR China
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Takamura Y, Kakuta H. In Vivo Receptor Visualization and Evaluation of Receptor Occupancy with Positron Emission Tomography. J Med Chem 2021; 64:5226-5251. [PMID: 33905258 DOI: 10.1021/acs.jmedchem.0c01714] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Positron emission tomography (PET) is useful for noninvasive in vivo visualization of disease-related receptors, for evaluation of receptor occupancy to determine an appropriate drug dosage, and for proof-of-concept of drug candidates in translational research. For these purposes, the specificity of the PET tracer for the target receptor is critical. Here, we review work in this area, focusing on the chemical structures of reported PET tracers, their Ki/Kd values, and the physical properties relevant to target receptor selectivity. Among these physical properties, such as cLogP, cLogD, molecular weight, topological polar surface area, number of hydrogen bond donors, and pKa, we focus especially on LogD and LogP as important physical properties that can be easily compared across a range of studies. We discuss the success of PET tracers in evaluating receptor occupancy and consider likely future developments in the field.
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Affiliation(s)
- Yuta Takamura
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Hiroki Kakuta
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
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Chang CW, Chiu CH, Lin MH, Wu HM, Yu TH, Wang PY, Kuo YY, Huang YY, Shiue CY, Huang WS, Yeh SHH. GMP-compliant fully automated radiosynthesis of [ 18F]FEPPA for PET/MRI imaging of regional brain TSPO expression. EJNMMI Res 2021; 11:26. [PMID: 33725191 PMCID: PMC7966678 DOI: 10.1186/s13550-021-00768-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/03/2021] [Indexed: 12/02/2022] Open
Abstract
Background Expression of translocator protein (TSPO) on the outer mitochondrial membrane of activated microglia is strongly associated with neuroinflammation. The second-generation PET ligand [18F]FEPPA specifically binds TSPO to enable in vivo visualization and quantification of neuroinflammation. We optimized a fully automated radiosynthesis method and evaluated the utility of [18F]FEPPA, the second-generation PET ligand specifically binds TSPO, in a mouse model of systemic LPS challenge to detect TSPO-associated signals of central and peripheral inflammation. In vivo dynamic PET/MR imaging was performed in LPS-induced and control mice after [18F]FEPPA administration. The relationship between the [18F]FEPPA signal and the dose of LPS was assessed. The cytokine levels (i.e., TNF-α, Il-1β, Il-6) in LPS-induced mice were measured by RT-PCR. Standard uptake value (SUV), total volume of distribution (VT) and area under the curve (AUC) were determined based on the metabolite-uncorrected plasma input function. Western blotting and immunostaining were used to measure TSPO expression in the brain. Results The fully automated [18F]FEPPA radiosynthesis produced an uncorrected radiochemical yield of 30 ± 2% within 80 min, with a radiochemical purity greater than 99% and specific activity of 148.9‒216.8 GBq/µmol. Significant differences were observed in the brain after [18F]FEPPA administration: SUV, VT and AUC were 1.61 ± 0.1, 1.25 ± 0.12 and 1.58 ± 0.09-fold higher in LPS-injected mice than controls. TNF-α, Il-1β and Il-6 mRNA levels were also elevated in the brains of LPS-injected mice. Western blotting revealed TSPO (p < 0.05) and Iba-1 (p < 0.01) were upregulated in the brain after LPS administration. In LPS-injected mice, TSPO immunoactivity colocalized with Iba-1 in the cerebrum and TSPO was significantly overexpressed in the hippocampus and cerebellum. The peripheral organs (heart, lung) of LPS-injected mice had higher [18F]FEPPA signal-to-noise ratios than control mice. Conclusions Based on the current data on ligand specificity and selectivity in central tissues using 7 T PET/MR imaging, we demonstrate that [18F]FEPPA accumulations significant increased in the specific brain regions of systemic LPS-induced neuroinflammation (5 mg/kg). Future investigations are needed to determine the sensitivity of [18F]FEPPA as a biomarker of neuroinflammation as well as the correlation between the PET signal intensity and the expression levels of TSPO. Supplementary Information The online version contains supplementary material available at 10.1186/s13550-021-00768-9.
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Affiliation(s)
- Chi-Wei Chang
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medical Imaging and Radiological Technology, The Institute of Radiological Sciences, Tzu Chi University of Science and Technology, Hualien City, Taiwan.,Department of Biomedical Engineering and Environmental Sciences, National Tsinghua University, Hsinchu, Taiwan
| | - Chuang-Hsin Chiu
- Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Ming-Hsien Lin
- Department of Nuclear Medicine, Cheng Hsin General Hospital, Taipei, Taiwan.,Department of Nuclear Medicine, Camillian Saint Mary's Hospital Luodong, Yilan, Taiwan
| | - Hung-Ming Wu
- Department of Neurology, Changhua Christian Hospital, Changhua, Taiwan
| | - Tsung-Hsun Yu
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Pao-Yeh Wang
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Yu-Yeh Kuo
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Ya-Yao Huang
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, 100, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Chyng-Yann Shiue
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan.,PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Wen-Sheng Huang
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Nuclear Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Skye Hsin-Hsien Yeh
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan.
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5
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Vass L, Fisk M, Lee S, Wilson FJ, Cheriyan J, Wilkinson I. Advances in PET to assess pulmonary inflammation: A systematic review. Eur J Radiol 2020; 130:109182. [DOI: 10.1016/j.ejrad.2020.109182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022]
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Tanimoto Y, Yamasaki T, Nagoshi N, Nishiyama Y, Nori S, Nishimura S, Iida T, Ozaki M, Tsuji O, Ji B, Aoki I, Jinzaki M, Matsumoto M, Fujibayashi Y, Zhang MR, Nakamura M, Okano H. In vivo monitoring of remnant undifferentiated neural cells following human induced pluripotent stem cell-derived neural stem/progenitor cells transplantation. Stem Cells Transl Med 2020; 9:465-477. [PMID: 31904914 PMCID: PMC7103627 DOI: 10.1002/sctm.19-0150] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 11/30/2019] [Indexed: 12/16/2022] Open
Abstract
Transplantation of human-induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs) is a promising treatment for a variety of neuropathological conditions. Although previous reports have indicated the effectiveness of hiPSC-NS/PCs transplantation into the injured spinal cord of rodents and nonhuman primates, long-term observation of hiPSC-NS/PCs post-transplantation suggested some "unsafe" differentiation-resistant properties, resulting in disordered overgrowth. These findings suggest that, even if "safe" NS/PCs are transplanted into the human central nervous system (CNS), the dynamics of cellular differentiation of stem cells should be noninvasively tracked to ensure safety. Positron emission tomography (PET) provides molecular-functional information and helps to detect specific disease conditions. The current study was conducted to visualize Nestin (an NS/PC marker)-positive undifferentiated neural cells in the CNS of immune-deficient (nonobese diabetic-severe combined immune-deficient) mice after hiPSC-NS/PCs transplantation with PET, using 18 kDa translocator protein (TSPO) ligands as labels. TSPO was recently found to be expressed in rodent NS/PCs, and its expression decreased with the progression of neuronal differentiation. We hypothesized that TSPO would also be present in hiPSC-NS/PCs and expressed strongly in residual immature neural cells after transplantation. The results showed high levels of TSPO expression in immature hiPSC-NS/PCs-derived cells, and decreased TSPO expression as neural differentiation progressed in vitro. Furthermore, PET with [18 F] FEDAC (a TSPO radioligand) was able to visualize the remnant undifferentiated hiPSC-NS/PCs-derived cells consisting of TSPO and Nestin+ cells in vivo. These findings suggest that PET with [18 F] FEDAC could play a key role in the safe clinical application of CNS repair in regenerative medicine.
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Affiliation(s)
- Yuji Tanimoto
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Tomoteru Yamasaki
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Narihito Nagoshi
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Yuichiro Nishiyama
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Satoshi Nori
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Soraya Nishimura
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Tsuyoshi Iida
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masahiro Ozaki
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Osahiko Tsuji
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Bin Ji
- Department of Functional Brain Imaging, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Ichio Aoki
- Institute for Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Masahiro Jinzaki
- Department of Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Morio Matsumoto
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Yasuhisa Fujibayashi
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
- Department of Radiology, Keio University School of Medicine, Tokyo, Japan
| | - Ming-Rong Zhang
- Department of Advanced Nuclear Medicine Sciences, National Institute of Radiological Sciences, Quantum Medical Science Directorate, National Institutes for Quantum and Radiological Science and Technology (QST), Chiba, Japan
| | - Masaya Nakamura
- Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
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Kubota K, Ogawa M, Ji B, Watabe T, Zhang MR, Suzuki H, Sawada M, Nishi K, Kudo T. Basic Science of PET Imaging for Inflammatory Diseases. PET/CT FOR INFLAMMATORY DISEASES 2020. [PMCID: PMC7418531 DOI: 10.1007/978-981-15-0810-3_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
FDG-PET/CT has recently emerged as a useful tool for the evaluation of inflammatory diseases too, in addition to that of malignant diseases. The imaging is based on active glucose utilization by inflammatory tissue. Autoradiography studies have demonstrated high FDG uptake in macrophages, granulocytes, fibroblasts, and granulation tissue. Especially, activated macrophages are responsible for the elevated FDG uptake in some types of inflammation. According to one study, after activation by lipopolysaccharide of cultured macrophages, the [14C]2DG uptake by the cells doubled, reaching the level seen in glioblastoma cells. In activated macrophages, increase in the expression of total GLUT1 and redistributions from the intracellular compartments toward the cell surface have been reported. In one rheumatoid arthritis model, following stimulation by hypoxia or TNF-α, the highest elevation of the [3H]FDG uptake was observed in the fibroblasts, followed by that in macrophages and neutrophils. As the fundamental mechanism of elevated glucose uptake in both cancer cells and inflammatory cells, activation of glucose metabolism as an adaptive response to a hypoxic environment has been reported, with transcription factor HIF-1α playing a key role. Inflammatory cells and cancer cells seem to share the same molecular mechanism of elevated glucose metabolism, lending support to the notion of usefulness of FDGPET/CT for the evaluation of inflammatory diseases, besides cancer.
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Fujinaga M, Kumata K, Zhang Y, Hatori A, Yamasaki T, Mori W, Ohkubo T, Xie L, Nengaki N, Zhang MR. Synthesis of two novel [ 18F]fluorobenzene-containing radiotracers via spirocyclic iodonium ylides and positron emission tomography imaging of translocator protein (18 kDa) in ischemic brain. Org Biomol Chem 2019; 16:8325-8335. [PMID: 30206613 DOI: 10.1039/c8ob01700j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Two novel radiotracers, namely, N-(4-[18F]fluorobenzyl)-N-methyl-2-(7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl)acetamide ([18F]5) and 2-(5-(4-[18F]fluorophenyl)-2-oxobenzo[d]oxazol-3(2H)-yl)-N-methyl-N-phenylacetamide ([18F]6), were developed for positron emission tomography (PET) imaging of translocator protein (18 kDa) (TSPO) in ischemic brain in this study. The two radiotracers with a [18F]fluorobenzene ring were derived from the corresponding [18F]fluoroethyl tracers [18F]7 and [18F]8 which underwent [18F]defluoroethylation in vivo easily. [18F]5 or [18F]6 was synthesized by the radiofluorination of the spirocyclic iodonium ylide precursor 10 or 17 with [18F]F- in 23 ± 10% (n = 7) or 56 ± 9% (n = 7) radiochemical yields (decay-corrected, based on [18F]F-). [18F]5 and [18F]6 showed high in vitro binding affinities (Ki = 0.70 nM and 5.9 nM) for TSPO and moderate lipophilicities (log D = 2.9 and 3.4). Low uptake of radioactivity for both radiotracers was observed in mouse bones. Metabolite analysis showed that the in vivo stability of [18F]5 and [18F]6 was improved in comparison to the parent radiotracers [18F]7 and [18F]8. In particular, no radiolabelled metabolite of [18F]5 was found in the mouse brains at 60 min after the radiotracer injection. PET studies with [18F]5 on ischemic rat brains revealed a higher binding potential (BPND = 3.42) and maximum uptake ratio (4.49) between the ipsilateral and contralateral sides. Thus, [18F]5 was shown to be a useful PET radiotracer for visualizing TSPO in neuroinflammation models.
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Affiliation(s)
- Masayuki Fujinaga
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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Manabe O, Kikuchi T, Scholte AJHA, El Mahdiui M, Nishii R, Zhang MR, Suzuki E, Yoshinaga K. Radiopharmaceutical tracers for cardiac imaging. J Nucl Cardiol 2018; 25:1204-1236. [PMID: 29196910 PMCID: PMC6133155 DOI: 10.1007/s12350-017-1131-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 11/05/2017] [Indexed: 12/13/2022]
Abstract
Cardiovascular disease (CVD) is the leading cause of death and disease burden worldwide. Nuclear myocardial perfusion imaging with either single-photon emission computed tomography or positron emission tomography has been used extensively to perform diagnosis, monitor therapies, and predict cardiovascular events. Several radiopharmaceutical tracers have recently been developed to evaluate CVD by targeting myocardial perfusion, metabolism, innervation, and inflammation. This article reviews old and newer used in nuclear cardiac imaging.
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Affiliation(s)
- Osamu Manabe
- Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Tatsuya Kikuchi
- Department of Radiopharmaceutical Development, National Institutes for Quantum and Radiological Science and Technology, National Institute of Radiological Sciences, Chiba, Japan
| | - Arthur J H A Scholte
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mohammed El Mahdiui
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ryuichi Nishii
- Diagnostic and Therapeutic Nuclear Medicine, National Institutes for Quantum and Radiological Science and Technology, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Radiopharmaceutical Development, National Institutes for Quantum and Radiological Science and Technology, National Institute of Radiological Sciences, Chiba, Japan
| | - Eriko Suzuki
- Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Keiichiro Yoshinaga
- Diagnostic and Therapeutic Nuclear Medicine, National Institutes for Quantum and Radiological Science and Technology, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan.
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10
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Auberson YP, Briard E, Rudolph B, Kaupmann K, Smith P, Oberhauser B. PET Imaging of T Cells: Target Identification and Feasibility Assessment. ChemMedChem 2018; 13:1566-1579. [DOI: 10.1002/cmdc.201800241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 05/23/2018] [Indexed: 01/21/2023]
Affiliation(s)
- Yves P. Auberson
- Global Discovery Chemistry Novartis Institutes for BioMedical Research 141 Klybeckstrasse 4057 Basel Switzerland
| | - Emmanuelle Briard
- Global Discovery Chemistry Novartis Institutes for BioMedical Research 141 Klybeckstrasse 4057 Basel Switzerland
| | - Bettina Rudolph
- Translational Medicine, Pharmacokinetics Sciences Novartis Institutes for BioMedical Research Novartis Campus 4056 Basel Switzerland
| | - Klemens Kaupmann
- Autoimmunity, Transplantation & Inflammation Novartis Institutes for BioMedical Research Novartis Campus 4056 Basel Switzerland
| | - Paul Smith
- Autoimmunity, Transplantation & Inflammation Novartis Institutes for BioMedical Research Novartis Campus 4056 Basel Switzerland
| | - Berndt Oberhauser
- Global Discovery Chemistry Novartis Institutes for BioMedical Research 141 Klybeckstrasse 4057 Basel Switzerland
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11
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Chung SJ, Yoon HJ, Youn H, Kim MJ, Lee YS, Jeong JM, Chung JK, Kang KW, Xie L, Zhang MR, Cheon GJ. 18F-FEDAC as a Targeting Agent for Activated Macrophages in DBA/1 Mice with Collagen-Induced Arthritis: Comparison with 18F-FDG. J Nucl Med 2018; 59:839-845. [DOI: 10.2967/jnumed.117.200667] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/13/2017] [Indexed: 11/16/2022] Open
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Kawamura K, Kumata K, Takei M, Furutsuka K, Hashimoto H, Ito T, Shiomi S, Fujishiro T, Watanabe R, Igarashi N, Muto M, Yamasaki T, Yui J, Xie L, Hatori A, Zhang Y, Nemoto K, Fujibayashi Y, Zhang MR. Efficient radiosynthesis and non-clinical safety tests of the TSPO radioprobe [(18)F]FEDAC: Prerequisites for clinical application. Nucl Med Biol 2016; 43:445-53. [PMID: 27183465 DOI: 10.1016/j.nucmedbio.2016.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/19/2016] [Accepted: 04/24/2016] [Indexed: 12/17/2022]
Abstract
INTRODUCTION [(18)F]FEDAC ([(18)F]1) has potent binding affinity and selectivity for translocator protein (18kDa, TSPO), and has been used to noninvasively visualize neuroinflammation, lung inflammation, acute liver damage, nonalcoholic fatty liver disease, and liver fibrosis. We had previously synthesized [(18)F]1 in two steps: (i) preparation of [(18)F]fluoroethyl bromide and (ii) coupling of [(18)F]fluoroethyl bromide with the appropriate precursor (2) for labeling. In this study, to clinically utilize [(18)F]1 as a PET radiopharmaceutical and to transfer the production technique of [(18)F]1 to other PET centers, we simplified its preparation by using a direct, one-step, tosyloxy-for-fluorine substitution. We also performed an acute toxicity study as a major non-clinical safety test, and determined radiometabolites using human liver microsomes. METHODS [(18)F]1 was prepared via direct (18)F-fluorination by heating the corresponding tosylated derivative (3) with [(18)F]fluoride as its Kryptofix 222 complex in dimethyl sulfoxide at 110°C for 15min, following by HPLC purification. Non-clinical safety tests were performed for the extended single-dose toxicity study in rats, and for the in vitro metabolite analysis with human liver microsomal incubation. RESULTS High quality batches of [(18)F]1, compatible with clinical applications, were obtained. At the end of irradiation, the decay-corrected radiochemical yield of [(18)F]1 using 1 and 5mg of precursor based on [(18)F]fluoride was 18.5±7.9% (n=10) and 52.0±5.8% (n=3), respectively. A single-dose of [(18)F]1 did not show toxicological effects for 14 days after the injection in male and female rats. In human liver microsomal incubations, [(18)F]1 was easily metabolized to [(18)F]desbenzyl-FEDAC ([(18)F]10) by CYPs (4.2% of parent compound left 60min after incubation). CONCLUSION We successfully synthesized clinical grade batches of [(18)F]1 and verified the absence of innocuity of this radiotracer. [(18)F]1 will be used to first-in-human studies in our facility.
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Affiliation(s)
- Kazunori Kawamura
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan.
| | - Katsushi Kumata
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Makoto Takei
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Kenji Furutsuka
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; SHI Accelerator Service Ltd., Tokyo 141-0032, Japan
| | - Hiroki Hashimoto
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Takehito Ito
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; SHI Accelerator Service Ltd., Tokyo 141-0032, Japan
| | - Satoshi Shiomi
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; Tokyo Nuclear Services, Tokyo 110-0016, Japan
| | - Tomoya Fujishiro
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; Tokyo Nuclear Services, Tokyo 110-0016, Japan
| | - Ryuji Watanabe
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; Tokyo Nuclear Services, Tokyo 110-0016, Japan
| | - Nobuyuki Igarashi
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; Tokyo Nuclear Services, Tokyo 110-0016, Japan
| | - Masatoshi Muto
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan; Tokyo Nuclear Services, Tokyo 110-0016, Japan
| | - Tomoteru Yamasaki
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Joji Yui
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Lin Xie
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Akiko Hatori
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Yiding Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Kazuyoshi Nemoto
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Yasuhisa Fujibayashi
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Radiopharmaceuticals Development, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
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Tiwari AK, Yui J, Zhang Y, Fujinaga M, Yamasaki T, Xie L, Shimoda Y, Kumata K, Hatori A, Zhang MR. [18F]FPBMP: – a potential new positron emission tomography radioligand for imaging of translocator protein (18 kDa) in peripheral organs of rats. RSC Adv 2015. [DOI: 10.1039/c5ra22594a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The five transmembrane translocator protein (18 kDa, TSPO) is abundantly expressed in the mitochondria of activated microglia (brain) and peripheral tissues, including those of the heart, lung and kidney.
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Vicidomini C, Panico M, Greco A, Gargiulo S, Coda ARD, Zannetti A, Gramanzini M, Roviello GN, Quarantelli M, Alfano B, Tavitian B, Dollé F, Salvatore M, Brunetti A, Pappatà S. In vivo imaging and characterization of [(18)F]DPA-714, a potential new TSPO ligand, in mouse brain and peripheral tissues using small-animal PET. Nucl Med Biol 2014; 42:309-16. [PMID: 25537727 DOI: 10.1016/j.nucmedbio.2014.11.009] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 02/05/2023]
Abstract
INTRODUCTION The translocator protein 18 kDa (TSPO), a biochemical marker of neuroinflammation, is highly expressed in the brain activated microglia and it is also expressed by peripheral inflammatory cells and normal peripheral tissues. Thus, development of radioligands for the TSPO may contribute to further understanding the in vivo TSPO function in central and peripheral inflammatory processes and other pathologies. Here, we report the biodistribution, the specific binding and the radiometabolites of [(18)F]DPA-714, a promising fluorinated PET radiotracer, in normal mice using a microPET/CT scanner. METHODS The in vivo biodistribution and kinetics of [(18)F]DPA-714 were measured in mice brain and peripheral tissues. Specific binding to TSPO sites was assessed using pharmacological competitive studies by means of saturation experiments performed by i.v. injection of 1mg/kg of unlabeled DPA-714 or 3mg/kg of unlabeled PK11195. A region of interest analysis was performed to generate time-activity curves in the brain, heart, lung, kidney, spleen and liver. Metabolites assay was performed in the plasma and peripheral organs by radio-HPLC. RESULTS [(18)F]DPA-714 reached high concentration in lung, heart, kidney and spleen, tissues well known to be rich in TSPO sites. [(18)F]DPA-714 kinetics were faster in the lung and slower in the kidney. Pre-injection of unlabeled DPA-714 or PK11195 inhibited about 80% of [(18)F]DPA-714 uptake in the lung and heart (p<0.0005). The percentage of inhibition in the kidney was lower and achieved at later times only with DPA-714 (p<0.05) but not with PK11195. Sixty minutes after radiotracer injection only unmetabolized radioligand was found in the brain, lung, heart and spleen. CONCLUSION These results suggest that [(18)F]DPA-714 is a suitable PET ligand for imaging in mice brain and peripheral tissues since it binds with high specificity TSPO binding sites and it is almost unchanged at 60 minutes after radiotracer injection in the brain and TSPO-rich regions.
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Affiliation(s)
- Caterina Vicidomini
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Mariarosaria Panico
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Adelaide Greco
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Sara Gargiulo
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Anna Rita Daniela Coda
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Antonella Zannetti
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Matteo Gramanzini
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | | | | | - Bruno Alfano
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy
| | - Bertrand Tavitian
- Inserm U970, PARCC, Université Paris Descartes, Hôpital Européen Georges Pompidou, Paris, France; CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Frederic Dollé
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Marco Salvatore
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy
| | - Arturo Brunetti
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy; CEINGE, Biotecnologie Avanzate, s.c.a.r.l., Naples, Italy
| | - Sabina Pappatà
- Institute of Biostructure and Bioimaging, CNR, Naples, Italy.
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PET imaging of lung inflammation with [18F]FEDAC, a radioligand for translocator protein (18 kDa). PLoS One 2012; 7:e45065. [PMID: 22984611 PMCID: PMC3440397 DOI: 10.1371/journal.pone.0045065] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 08/14/2012] [Indexed: 12/02/2022] Open
Abstract
Purpose The translocator protein (18 kDa) (TSPO) is highly expressed on the bronchial and bronchiole epithelium, submucosal glands in intrapulmonary bronchi, pneumocytes and alveolar macrophages in human lung. This study aimed to perform positron emission tomography (PET) imaging of lung inflammation with [18F]FEDAC, a specific TSPO radioligand, and to determine cellular sources enriching TSPO expression in the lung. Methods An acute lung injury model was prepared by intratracheal administration of lipopolysaccharide (LPS) to rat. Uptake of radioactivity in the rat lungs was measured with small-animal PET after injection of [18F]FEDAC. Presence of TSPO was examined in the lung tissue using Western blot and immunohistochemical assays. Results The uptake of [18F]FEDAC increased in the lung with the progress of inflammation by treatment with LPS. Pretreatment with a TSPO-selective ligand PK11195 showed a significant decrease in the lung uptake of [18F]FEDAC due to competitive binding to TSPO. TSPO expression was elevated in the inflamed lung section and its level responded to the [18F]FEDAC uptake and severity of inflammation. Increase of TSPO expression was mainly found in the neutrophils and macrophages of inflamed lungs. Conclusion From this study we conclude that PET with [18F]FEDAC may be a useful tool for imaging TSPO expression and evaluating progress of lung inflammation. Study on human lung using [18F]FEDAC-PET is promising.
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Xie L, Yamasaki T, Ichimaru N, Yui J, Kawamura K, Kumata K, Hatori A, Nonomura N, Zhang MR, Li XK, Takahara S. [11C]DAC-PET for Noninvasively Monitoring Neuroinflammation and Immunosuppressive Therapy Efficacy in Rat Experimental Autoimmune Encephalomyelitis Model. J Neuroimmune Pharmacol 2011; 7:231-42. [DOI: 10.1007/s11481-011-9322-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2011] [Accepted: 10/17/2011] [Indexed: 11/30/2022]
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Kumata K, Yui J, Hatori A, Fujinaga M, Yanamoto K, Yamasaki T, Kawamura K, Wakizaka H, Nengaki N, Yoshida Y, Ogawa M, Fukumura T, Zhang MR. Synthesis and Evaluation of Novel Carbon-11 Labeled Oxopurine Analogues for Positron Emission Tomography Imaging of Translocator Protein (18 kDa) in Peripheral Organs. J Med Chem 2011; 54:6040-9. [DOI: 10.1021/jm200516a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Katsushi Kumata
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Joji Yui
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Akiko Hatori
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Masayuki Fujinaga
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Kazuhiko Yanamoto
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Tomoteru Yamasaki
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Kazunori Kawamura
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Hidekatsu Wakizaka
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Nobuki Nengaki
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., 5-9-11 Kitashinagawa, Shinagawa-ku, Tokyo 141-8686, Japan
| | - Yuichiro Yoshida
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., 5-9-11 Kitashinagawa, Shinagawa-ku, Tokyo 141-8686, Japan
| | - Masanao Ogawa
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
- SHI Accelerator Service Co. Ltd., 5-9-11 Kitashinagawa, Shinagawa-ku, Tokyo 141-8686, Japan
| | - Toshimitsu Fukumura
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Ming-Rong Zhang
- Department of Molecular Probes, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
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