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Rotstein BH, Liang SH, Belov VV, Livni E, Levine DB, Bonab AA, Papisov MI, Perlis RH, Vasdev N. Practical Radiosynthesis and Preclinical Neuroimaging of [11C]isradipine, a Calcium Channel Antagonist. Molecules 2015; 20:9550-9. [PMID: 26016546 PMCID: PMC4870226 DOI: 10.3390/molecules20069550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 05/19/2015] [Accepted: 05/20/2015] [Indexed: 11/30/2022] Open
Abstract
In the interest of developing in vivo positron emission tomography (PET) probes for neuroimaging of calcium channels, we have prepared a carbon-11 isotopologue of a dihydropyridine Ca2+-channel antagonist, isradipine. Desmethyl isradipine (4-(benzo[c][1,2,5]oxadiazol-4-yl)-5-(isopropoxycarbonyl)-2,6-dimethyl-1,4-dihydropyridine-3-carboxylic acid) was reacted with [11C]CH3I in the presence of tetrabutylammonium hydroxide in DMF in an HPLC injector loop to produce the radiotracer in a good yield (6 ± 3% uncorrected radiochemical yield) and high specific activity (143 ± 90 GBq·µmol−1 at end-of-synthesis). PET imaging of normal rats revealed rapid brain uptake at baseline (0.37 ± 0.08% ID/cc (percent of injected dose per cubic centimeter) at peak, 15–60 s), which was followed by fast washout. After pretreatment with isradipine (2 mg·kg−1, i.p.), whole brain radioactivity uptake was diminished by 25%–40%. This preliminary study confirms that [11C]isradipine can be synthesized routinely for research studies and is brain penetrating. Further work on Ca2+-channel radiotracer development is planned.
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Affiliation(s)
- Benjamin H Rotstein
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Steven H Liang
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Vasily V Belov
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Eli Livni
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
| | - Dylan B Levine
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Ali A Bonab
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Mikhail I Papisov
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
- Department of Research, Shriners Hospitals for Children-Boston, 51 Blossom Street, Boston, MA 02114, USA.
| | - Roy H Perlis
- Department of Psychiatry and Center for Experimental Drugs and Diagnostics, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA.
| | - Neil Vasdev
- Department of Radiology, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging and Center for Advanced Medical Imaging Sciences, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA.
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Stone-Elander SA, Elander N, Thorell JO, Solås G, Svennebrink J. A single-mode microwave cavity for reducing radiolabelling reaction times, demonstrated by alkylations with [11C]alkyl halides. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580341008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Ishiwata K, Seki H, Ishii K, Ishii S, Nozaki T, Senda M. Synthesis and in vivo evaluation of [11C]semotiadil, a benzothiazine calcium antagonist. Appl Radiat Isot 1994; 45:439-43. [PMID: 8186770 DOI: 10.1016/0969-8043(94)90108-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A carbon-11 labeled benzothiazine calcium antagonist, (+)-(R)-2-[5-methoxy-2-[3-[methyl[2-[(3,4- methylenedioxy)phenoxy]ethyl]amino]propoxy]phenyl]-4-methyl-2H-1,4- benzothiazin-3(4H)-one (semotiadil), and its enantiomer were prepared by N-methylation of the corresponding norderivatives with 11CH3I: decay-corrected radiochemical yields of 16-27% based on 11CH3I, radiochemical, chemical and optical purity of > 99%, sp. act. of 11-50 GBq/mumol and preparation time of 35-40 min. In mice, saturable and stereo-selective uptake in the hippocampus, striatum and hypothalamus was observed. The potential of the compound to visualize the regional brain calcium channels in vivo by positron emission tomography was indicated; however, no promising sign was found in the myocardium.
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Affiliation(s)
- K Ishiwata
- Positron Medical Center, Tokyo Metropolitan Institute of Gerontology, Japan
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