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Mattingly SJ, Wuest M, Fine EJ, Schirrmacher R, Wuest F. Synthesis and in vivo evaluation of a radiofluorinated ketone body derivative. RSC Med Chem 2020; 11:297-306. [PMID: 33479637 PMCID: PMC7580772 DOI: 10.1039/c9md00486f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/02/2020] [Indexed: 12/28/2022] Open
Abstract
The ketone bodies d-beta-hydroxybutyric acid and acetoacetic acid represent the principal oxidative energy sources of most tissues when dietary glucose is scarce. An 18F-labeled ketone body could be a useful tool for studying ketone body metabolism using positron emission tomography (PET). Here, we report the first radiofluorinated ketone body derivative (3S)-4-[18F]fluoro-3-hydroxybutyric acid ([18F]FBHB) as well as its enantiomer and l-beta-hydroxybutyric acid derivative, (3R)-4-[18F]fluoro-3-hydroxybutyric acid ((R)-[18F]F3HB). PET imaging in mice showed biodistribution profiles of the radiotracers that were consistent with the biodistribution of the respective endogenous compounds. Moreover, both enantiomers visualized breast cancer xenografts in vivo. Fasting over 24 h showed significantly enhanced brain and heart uptake of [18F]FBHB and tumor uptake of (R)-[18F]F3HB. Disorders exhibiting altered energy substrate utilization, such as Alzheimer's disease, epilepsy, diabetes, and cancer may be of interest for PET imaging studies using [18F]FBHB.
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Affiliation(s)
| | - Melinda Wuest
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Cancer Research Institute of Northern Alberta , University of Alberta , Edmonton , Canada
| | - Eugene J Fine
- Department of Radiology (Nuclear Medicine) , Albert Einstein College of Medicine/Montefiore Medical Center , NY , NY , USA
| | - Ralf Schirrmacher
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Department of Chemistry , University of Alberta , Edmonton , Canada
| | - Frank Wuest
- Department of Oncology , University of Alberta , Edmonton , Canada .
- Cancer Research Institute of Northern Alberta , University of Alberta , Edmonton , Canada
- Department of Chemistry , University of Alberta , Edmonton , Canada
- Faculty of Pharmacy and Pharmaceutical Sciences , University of Alberta , Edmonton , Canada
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Christensen NL, Jakobsen S, Schacht AC, Munk OL, Alstrup AKO, Tolbod LP, Harms HJ, Nielsen S, Gormsen LC. Whole-Body Biodistribution, Dosimetry, and Metabolite Correction of [ 11C]Palmitate: A PET Tracer for Imaging of Fatty Acid Metabolism. Mol Imaging 2018; 16:1536012117734485. [PMID: 29073808 PMCID: PMC5665104 DOI: 10.1177/1536012117734485] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Despite the decades long use of [11C]palmitate positron emission tomography (PET)/computed tomography in basic metabolism studies, only personal communications regarding dosimetry and biodistribution data have been published. METHODS Dosimetry and biodistribution studies were performed in 2 pigs and 2 healthy volunteers by whole-body [11C]palmitate PET scans. Metabolite studies were performed in 40 participants (healthy and with type 2 diabetes) under basal and hyperinsulinemic conditions. Metabolites were estimated using 2 approaches and subsequently compared: Indirect [11C]CO2 release and parent [11C]palmitate measured by a solid-phase extraction (SPE) method. Finally, myocardial fatty acid uptake was calculated in a patient cohort using input functions derived from individual metabolite correction compared with population-based metabolite correction. RESULTS In humans, mean effective dose was 3.23 (0.02) µSv/MBq, with the liver and myocardium receiving the highest absorbed doses. Metabolite correction using only [11C]CO2 estimates underestimated the fraction of metabolites in studies lasting more than 20 minutes. Population-based metabolite correction showed excellent correlation with individual metabolite correction in the cardiac PET validation cohort. CONCLUSION First, mean effective dose of [11C]palmitate is 3.23 (0.02) µSv/MBq in humans allowing multiple scans using ∼300 MBq [11C]palmitate, and secondly, population-based metabolite correction compares well with individual correction.
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Affiliation(s)
- Nana L Christensen
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Steen Jakobsen
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Anna C Schacht
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Ole L Munk
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Aage K O Alstrup
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Lars P Tolbod
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Hendrik J Harms
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
| | - Søren Nielsen
- 2 Department of Endocrinology, Aarhus University Hospital, Aarhus C, Denmark
| | - Lars C Gormsen
- 1 Department of Nuclear Medicine & PET Centre, Aarhus University Hospital, Aarhus C, Denmark
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Nemanich S, Rani S, Shoghi K. In vivo multi-tissue efficacy of peroxisome proliferator-activated receptor-γ therapy on glucose and fatty acid metabolism in obese type 2 diabetic rats. Obesity (Silver Spring) 2013; 21:2522-9. [PMID: 23512563 PMCID: PMC3695080 DOI: 10.1002/oby.20378] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 01/07/2013] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To identify the disturbances in glucose and lipid metabolism observed in type 2 diabetes mellitus, we examined the interaction and contribution of multiple tissues (liver, heart, muscle, and brown adipose tissue) and monitored the effects of the Peroxisome Proliferator-Activated Receptor-γ (PPARγ) agonist rosiglitazone (RGZ) on metabolism in these tissues. DESIGN AND METHODS Rates of [(18) F]fluorodeoxyglucose ([(18) F]FDG) and [(11) C]Palmitate uptake and utilization in the Zucker diabetic fatty (ZDF) rat were quantified using noninvasive positron emission tomography imaging and quantitative modeling in comparison to lean Zucker rats. Furthermore, we studied two separate groups of RGZ-treated and untreated ZDF rats. RESULTS Glucose uptake is impaired in ZDF brown fat, muscle, and heart tissues compared to leans, while RGZ treatment increased glucose uptake compared to untreated ZDF rats. Fatty acid (FA) uptake decreased, but FA flux increased in brown fat and skeletal muscle of ZDF rats. RGZ treatment increased uptake of FA in brown fat but decreased uptake and utilization in liver, muscle, and heart. CONCLUSION Our data indicate tissue-specific mechanisms for glucose and FA disposal as well as differential action of insulin-sensitizing drugs to normalize substrate handling and highlight the role that preclinical imaging may play in screening drugs for obesity and diabetes.
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Affiliation(s)
- Samuel Nemanich
- Department of Radiology, Washington University in St. Louis, Saint Louis, MO
| | - Sudheer Rani
- Department of Radiology, Washington University in St. Louis, Saint Louis, MO
| | - Kooresh Shoghi
- Department of Radiology, Washington University in St. Louis, Saint Louis, MO
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, Saint Louis, MO
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Whitehead TD, Nemanich ST, Dence C, Shoghi KI. A PET-compatible tissue bioreactor for research, discovery, and validation of imaging biomarkers and radiopharmaceuticals: system design and proof-of-concept studies. J Nucl Med 2013; 54:1812-9. [PMID: 23978447 DOI: 10.2967/jnumed.113.119776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED Research and discovery of novel radiopharmaceuticals and targets thereof generally involves initial studies in cell cultures, followed by animal studies, both of which present several inherent limitations. The objective of this work was to develop a tissue bioreactor (TBR) enabling modulation of the microenvironment and to integrate the TBR with a small-animal PET scanner to facilitate imaging biomarker research and discovery and validation of radiopharmaceuticals. METHODS The TBR chamber is a custom-blown, water-jacketed, glass vessel enclosed in a circulating perfusion bath powered by a peristaltic pump, which is integrated within the field of view of the PET scanner. The chamber is in series with a gas exchanger and a vessel for degassing the system during filling. Dissolved oxygen/temperature probes and septa for injection or sampling are located at the inlet and outlet of the cell chamber. A pH probe is located at the chamber outlet. Effluent is collected in the fraction collector as mixed-cup samples. In addition, both medium and tissue chamber can be sampled to investigate tissue and secretory products through multiscale analysis. As a proof of concept, we studied the effects of lipids on glucose uptake using HepG2 cells. To that end, we varied the nutrient substrate environment over a period of approximately 27 d, before and after the addition of lipids, and studied the effects of pioglitazone, a peroxisome proliferator-activated receptor γ agonist, on lipid and glucose uptake. In parallel, the TBR was imaged by PET in conjunction with (11)C-palmitate in the presence and absence of lipids to characterize (11)C-palmitate uptake. RESULTS The O2 consumption, glucose consumption, lactate production, and free fatty acid consumption and production rates were consistent in demonstrating the effects of lipids on glucose uptake. Pioglitazone exhibited improved glucose uptake within 3 d of treatment. Semiquantitative analysis suggested that lipids induced greater (11)C-palmitate uptake. CONCLUSION The integrated TBR offers a platform to monitor and modulate the tissue microenvironment, thus facilitating tissue-specific imaging and therapeutic biomarkers of disease, identification of molecular diagnostic markers, and validation of radiopharmaceuticals in both rodent and human cell lines.
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Affiliation(s)
- Timothy D Whitehead
- Department of Radiology, Washington University in St. Louis, St. Louis, Missouri
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Mock BH, Brown-Proctor C, Green MA, Steele B, Glick-Wilson BE, Zheng QH. An automated SPE-based high-yield synthesis of [11C]acetate and [11C]palmitate: no liquid-liquid extraction, solvent evaporation or distillation required. Nucl Med Biol 2011; 38:1135-42. [PMID: 21831651 DOI: 10.1016/j.nucmedbio.2011.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 05/05/2011] [Accepted: 05/13/2011] [Indexed: 11/29/2022]
Abstract
INTRODUCTION An automated method is described for the rapid and high-yield synthesis of two of the most commonly used radioactive fatty acids: [(11)C]acetate and [(11)C]palmitate. METHODS Reaction of [(11)C]CO(2) with the respective Grignard reagents in diethyl ether solution proceeded for 2 min at 40°C. Quenching of the reaction and liberation of nonreacted [(11)C]CO(2) occurred upon addition of a fourfold molar excess of aqueous 0.1 M HCl (acetate) or nonaqueous HCl/Et(2)O (palmitate). Labeled products were then purified by adsorption to an Alumina-N Sep-Pak Plus cartridge and eluted with either aqueous NaH(2)PO(4) solution (acetate) or 100% ethanol (palmitate). RESULTS High-performance liquid chromatography analysis confirmed that the radiochemical purity of each product was >98%, and decay-corrected radiochemical yields averaged 33% for [(11)C]palmitate and 40% for [(11)C]acetate. CONCLUSION The method requires no liquid-liquid extraction, solvent evaporation or distillation capabilities and can be readily adapted to existing radiosynthesis modules.
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Affiliation(s)
- Bruce H Mock
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202-2111, USA
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Abstract
In the myocardial cell, a series of enzyme-catalyzed reactions results in the efficient transfer of chemical energy into mechanical energy. The goals of this article are to emphasize the ability of noninvasive imaging techniques using isotopic tracers to detect the metabolic footprints of heart disease and to propose that cardiac metabolic imaging is more than a useful adjunct to current myocardial perfusion imaging studies. A strength of metabolic imaging is in the assessment of regional myocardial differences in metabolic activity, probing for 1 substrate at a time. We hope that new and developing methods of cardiac imaging will lead to the earlier detection of heart disease and improve the management and quality of life for patients afflicted with ischemic and nonischemic heart muscle disorders.
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Affiliation(s)
- Heinrich Taegtmeyer
- Division of Cardiology, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas 77030, USA.
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Shoghi KI, Finck BN, Schechtman KB, Sharp T, Herrero P, Gropler RJ, Welch MJ. In vivo metabolic phenotyping of myocardial substrate metabolism in rodents: differential efficacy of metformin and rosiglitazone monotherapy. Circ Cardiovasc Imaging 2009; 2:373-81. [PMID: 19808625 DOI: 10.1161/circimaging.108.843227] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cardiovascular disease is the leading cause of death among diabetic patients, with alteration in myocardial substrate metabolism being a likely contributor. We aimed to assess noninvasively the efficacy of metformin and rosiglitazone monotherapy in normalizing myocardial substrate metabolism in an animal model of type 2 diabetes mellitus. METHODS AND RESULTS The study used 18 male ZDF rats (fa/fa) with 6 rats in each group: an untreated group; a group treated with metformin (16.6 mg/kg/d), and a group treated with rosiglitazone (4 mg/kg). Each rat was scanned at age 14 weeks (baseline) and subsequently at 19 weeks with small-animal positron emission tomography to estimate myocardial glucose utilization (MGU) and myocardial utilization (MFAU), oxidation (MFAO), and esterification (MFAE). Treatment lasted for 5 weeks after baseline imaging. At week 19, rats were euthanized and hearts were extracted for expression analysis of select genes encoding for GLUT transporters and fatty acid transport and oxidation genes. In addition, echocardiography measurements were obtained at weeks 13 and 18 to characterize cardiac function. Metformin had no significant effect on either MGU or MFAU and MFAO. In contrast, rosiglitazone tended to enhance MGU and significantly reduced MFAU and MFAO. Rosiglitazone-induced increase in glucose uptake correlated significantly with increased expression of GLUT4, whereas diminished MFAO correlated significantly with decreased expression of FATP-1 and MCAD. Finally, changes in fractional shortening as a measure of cardiac function were unchanged throughout the study. CONCLUSIONS Treatment with rosiglitazone enhanced glucose utilization and diminished MFAO, thus reversing the metabolic phenotype of the diabetic heart.
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Affiliation(s)
- Kooresh I Shoghi
- Mallinckrodt Institute of Radiology, Division of Radiological Sciences, Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA.
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Russell RR. Myocardial metabolic imaging: Viability and beyond. CURRENT CARDIOVASCULAR IMAGING REPORTS 2009. [DOI: 10.1007/s12410-009-0027-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Nuclear cardiology has made significant advances since the first reports of planar scintigraphy for the evaluation of left ventricular perfusion and function. While the current "state of the art" of gated myocardial perfusion single-photon emission computed tomographic (SPECT) imaging offers invaluable diagnostic and prognostic information for the evaluation of patients with suspected or known coronary artery disease (CAD), advances in the cellular and molecular biology of the cardiovascular system have helped to usher in a new modality in nuclear cardiology, namely, molecular imaging. In this review, we will discuss the current state of the art in nuclear cardiology, which includes SPECT and positron emission tomographic evaluation of myocardial perfusion, evaluation of left ventricular function by gated myocardial perfusion SPECT and gated blood pool SPECT, and the evaluation of myocardial viability with PET and SPECT methods. In addition, we will discuss the future of nuclear cardiology and the role that molecular imaging will play in the early detection of CAD at the level of the vulnerable plaque, the evaluation of cardiac remodeling, and monitoring of important new therapies including gene therapy and stem cell therapy.
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Sharp TL, Dence CS, Engelbach JA, Herrero P, Gropler RJ, Welch MJ. Techniques necessary for multiple tracer quantitative small-animal imaging studies. Nucl Med Biol 2006; 32:875-84. [PMID: 16253813 DOI: 10.1016/j.nucmedbio.2005.05.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 05/31/2005] [Accepted: 05/31/2005] [Indexed: 11/27/2022]
Abstract
INTRODUCTION An increasing number and variety of studies on rodent models are being conducted using small-animal positron emission tomography scanners. We aimed to determine if animal handling techniques could be developed to perform routine animal imaging in a timely and efficient manner and with minimal effect on animal physiology. These techniques need to be reproducible in the same animal while maintaining hemodynamic and physiological stability. METHODS The necessary techniques include (a) the use of inhalant anesthesia, (b) arterial and venous cannulation for multiple tracer administrations and blood sampling, (c) development of small-volume analytic columns and techniques and (d) measurement of the physiological environment during the imaging session. RESULTS We provide an example of a cardiac imaging study using four radiotracers (15O-water, 1-[11C]-acetate, 1-[11C]-palmitate and 1-[11C]-glucose) injected into normal rats. Plasma substrates, CO2 production and total metabolites were measured. The animals remained anesthetized over the entire imaging session, and their physiological state was maintained. CONCLUSION The intrastudy stability of the physiological measurements and substrate levels and interstudy reproducibility of the measurements are reported.
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Affiliation(s)
- Terry L Sharp
- Division of Radiological Sciences, The Mallinckrodt Institute of Radiology, Washington University School of Medicine, Campus Box 8225, St. Louis, MO 63110, USA
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