1
|
Tutov A, Chen X, Werner RA, Mühlig S, Zimmermann T, Nose N, Koshino K, Lapa C, Decker M, Higuchi T. Rationalizing the Binding Modes of PET Radiotracers Targeting the Norepinephrine Transporter. Pharmaceutics 2023; 15:pharmaceutics15020690. [PMID: 36840011 PMCID: PMC9963373 DOI: 10.3390/pharmaceutics15020690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/09/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
PURPOSE A new PET radiotracer 18F-AF78 showing great potential for clinical application has been reported recently. It belongs to a new generation of phenethylguanidine-based norepinephrine transporter (NET)-targeting radiotracers. Although many efforts have been made to develop NET inhibitors as antidepressants, systemic investigations of the structure-activity relationships (SARs) of NET-targeting radiotracers have rarely been performed. METHODS Without changing the phenethylguanidine pharmacophore and 3-fluoropropyl moiety that is crucial for easy labeling, six new analogs of 18F-AF78 with different meta-substituents on the benzene-ring were synthesized and evaluated in a competitive cellular uptake assay and in in vivo animal experiments in rats. Computational modeling of these tracers was established to quantitatively rationalize the interaction between the radiotracers and NET. RESULTS Using non-radiolabeled reference compounds, a competitive cellular uptake assay showed a decrease in NET-transporting affinity from meta-fluorine to iodine (0.42 and 6.51 µM, respectively), with meta-OH being the least active (22.67 µM). Furthermore, in vivo animal studies with radioisotopes showed that heart-to-blood ratios agreed with the cellular experiments, with AF78(F) exhibiting the highest cardiac uptake. This result correlates positively with the electronegativity rather than the atomic radius of the meta-substituent. Computational modeling studies revealed a crucial influence of halogen substituents on the radiotracer-NET interaction, whereby a T-shaped π-π stacking interaction between the benzene-ring of the tracer and the amino acid residues surrounding the NET binding site made major contributions to the different affinities, in accordance with the pharmacological data. CONCLUSION The SARs were characterized by in vitro and in vivo evaluation, and computational modeling quantitatively rationalized the interaction between radiotracers and the NET binding site. These findings pave the way for further evaluation in different species and underline the potential of AF78(F) for clinical application, e.g., cardiac innervation imaging or molecular imaging of neuroendocrine tumors.
Collapse
Affiliation(s)
- Anna Tutov
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy and Food Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Xinyu Chen
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, D-86156 Augsburg, Germany
- Department of Nuclear Medicine and Comprehensive Heart Failure Center, University Hospital Würzburg, D-97080 Würzburg, Germany
| | - Rudolf A. Werner
- Department of Nuclear Medicine and Comprehensive Heart Failure Center, University Hospital Würzburg, D-97080 Würzburg, Germany
- Division of Nuclear Medicine, The Russell H Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Saskia Mühlig
- Department of Nuclear Medicine and Comprehensive Heart Failure Center, University Hospital Würzburg, D-97080 Würzburg, Germany
| | - Thomas Zimmermann
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy and Food Chemistry, University of Würzburg, D-97074 Würzburg, Germany
| | - Naoko Nose
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-0082, Japan
| | - Kazuhiro Koshino
- Department of Systems and Informatics, Hokkaido Information University, Ebetsu 069-0832, Japan
| | - Constantin Lapa
- Nuclear Medicine, Faculty of Medicine, University of Augsburg, D-86156 Augsburg, Germany
| | - Michael Decker
- Pharmaceutical and Medicinal Chemistry, Institute of Pharmacy and Food Chemistry, University of Würzburg, D-97074 Würzburg, Germany
- Correspondence: (M.D.); (T.H.); Tel.: +49-(931)-201-35455 (T.H.)
| | - Takahiro Higuchi
- Department of Nuclear Medicine and Comprehensive Heart Failure Center, University Hospital Würzburg, D-97080 Würzburg, Germany
- Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-0082, Japan
- Correspondence: (M.D.); (T.H.); Tel.: +49-(931)-201-35455 (T.H.)
| |
Collapse
|
2
|
Bamminger K, Raitanen J, Karanikas G, Rasul S, Nics L, Mitterhauser M, Wadsak W, Hacker M, Pichler V, Vraka C. Rapid, high-yield enzymatic synthesis of n.c.a. 6-[ 18F]fluorodopamine (6-[ 18F]FDA) for in vivo application. Nucl Med Biol 2022; 114-115:189-197. [PMID: 35820986 DOI: 10.1016/j.nucmedbio.2022.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 04/08/2022] [Accepted: 07/01/2022] [Indexed: 12/27/2022]
Affiliation(s)
- Karsten Bamminger
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; CBmed GmbH - Center for Biomarker Research in Medicine, Graz, Austria
| | - Julia Raitanen
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria; University of Vienna, Vienna Doctoral School in Chemistry (DoSChem), Währinger Str. 42, 1090 Vienna, Austria
| | - Georgios Karanikas
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Sazan Rasul
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Markus Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; CBmed GmbH - Center for Biomarker Research in Medicine, Graz, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Verena Pichler
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria.
| | - Chrysoula Vraka
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
3
|
Képes Z, Mikó M, Kukuts K, Esze R, Barna S, Somodi S, Káplár M, Varga J, Garai I. Imaging with [ 99mTc]HMPAO - a novel perspective: investigation of [ 99mTc]HMPAO leg muscle uptake in metabolic diseases. Acta Radiol 2021; 64:187-194. [PMID: 34894745 DOI: 10.1177/02841851211063601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Sensitive imaging modalities in the diagnosis of microcircular complications of the lower extremities induced by metabolic diseases are becoming a focus of interest. PURPOSE To investigate the [99mTc]HMPAO uptake of the legs in type 2 diabetes mellitus (T2DM) and obesity, and to search for associations with clinical parameters and nerve conducting studies. MATERIAL AND METHODS A total of 57 patients with controlled T2DM and 46 obese participants without DM were enrolled in the study. [99mTc]HMPAO SPECT/CT examinations were performed to evaluate the radiopharmaceutical accumulation of the legs. For the quantitative assessment of tracer uptake, standardized uptake value (SUVpeak) was measured in fixed spheric volumes of interest placed on both sural muscles on the attenuation-corrected images. Measurement of current perception threshold applying Neurometer (NM-01/CPT) was used to evaluate peripheral nerve dysfunction. Laboratory parameters assessing the glucose homeostasis of the study participants were also measured. RESULTS In the diabetic group, significantly lower leg SUV values were detected compared to the non-DM obese group (median: 0.517 vs. 0.607; P < 0.001). Body mass index (BMI) (P < 0.0001), age (P = 0.0283), HbA1c (P = 0.0068), and glucose level (P = 0.0044) proved to be significant predictors of muscle tracer uptake. Neurometer studies showed positive correlation with HbA1c levels in the T2DM group (P = 0.0002). CONCLUSION We assume that [99mTc]HMPAO uptake of leg muscles is associated with microcirculation, so quantitative [99mTc]HMPAO SPECT/CT might be a sensitive method for evaluating lower limb microvascular alterations. BMI, age, HbA1c, and glucose level may be significant predictors of peripheral vascular abnormalities triggered by metabolic disturbances.
Collapse
Affiliation(s)
- Zita Képes
- Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Márton Mikó
- Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Kornél Kukuts
- Scanomed Ltd Nuclear Medicine Centres Debrecen, Debrecen, Hungary
| | - Regina Esze
- Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Sándor Barna
- Scanomed Ltd Nuclear Medicine Centres Debrecen, Debrecen, Hungary
| | - Sándor Somodi
- Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklós Káplár
- Department of Internal Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - József Varga
- Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ildikó Garai
- Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Scanomed Ltd Nuclear Medicine Centres Debrecen, Debrecen, Hungary
| |
Collapse
|
4
|
Lamotte G, Holmes C, Sullivan P, Lenka A, Goldstein DS. Cardioselective peripheral noradrenergic deficiency in Lewy body synucleinopathies. Ann Clin Transl Neurol 2020; 7:2450-2460. [PMID: 33216462 PMCID: PMC7732242 DOI: 10.1002/acn3.51243] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/20/2020] [Indexed: 12/18/2022] Open
Abstract
Objective Lewy body (LB) synucleinopathies such as Parkinson’s disease (PD) entail profound cardiac norepinephrine deficiency. The status of sympathetic noradrenergic innervation at other extracranial sites has been unclear. Although in vivo neuroimaging studies have indicated a cardioselective noradrenergic lesion, no previous study has surveyed peripheral organs for norepinephrine contents in LB diseases. We reviewed 18F‐dopamine (18F‐DA) positron emission tomographic images and postmortem neurochemical data across several body organs of controls and patients with the LB synucleinopathies PD and pure autonomic failure (PAF) and the non‐LB synucleinopathy multiple system atrophy (MSA). Methods 18F‐DA–derived radioactivity in the heart, liver, spleen, pancreas, stomach, kidneys, thyroid, and submandibular glands were analyzed from 145 patients with LB synucleinopathies (112 PD, 33 PAF), 74 controls, and 85 MSA patients. In largely separate cohorts, postmortem tissue norepinephrine data were reviewed for heart, liver, spleen, pancreas, kidney, thyroid, submandibular gland, and sympathetic ganglion tissue from 38 PD, 2 PAF, and 5 MSA patients and 35 controls. Results Interventricular septal 18F‐DA–derived radioactivity was decreased in the LB synucleinopathy group compared to the control and MSA groups (P < 0.0001 each). The LB and non‐LB groups did not differ in liver, spleen, pancreas, stomach, or kidney 18F‐DA–derived radioactivity. The LB synucleinopathy group had markedly decreased apical myocardial norepinephrine, but normal tissue norepinephrine in other organs. The MSA group had normal tissue norepinephrine in all examined organs. Interpretation By in vivo sympathetic neuroimaging and postmortem neurochemistry peripheral noradrenergic deficiency in LB synucleinopathies is cardioselective. MSA does not involve peripheral noradrenergic deficiency.
Collapse
Affiliation(s)
- Guillaume Lamotte
- Clinical Neurosciences Program (CNP), Division of Intramural Research (DIR), National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, Maryland, USA.,Autonomic Medicine Section, CNP/DIR/NINDS/NIH, Bethesda, Maryland, USA
| | - Courtney Holmes
- Autonomic Medicine Section, CNP/DIR/NINDS/NIH, Bethesda, Maryland, USA
| | - Patricia Sullivan
- Autonomic Medicine Section, CNP/DIR/NINDS/NIH, Bethesda, Maryland, USA
| | - Abhishek Lenka
- Department of Neurology, Medstar Georgetown University Hospital, Washington, District of Columbia, USA
| | - David S Goldstein
- Autonomic Medicine Section, CNP/DIR/NINDS/NIH, Bethesda, Maryland, USA
| |
Collapse
|
5
|
Goldstein DS, Isonaka R, Holmes C, Ding YS, Sharabi Y. Cardiac sympathetic innervation and vesicular storage in pure autonomic failure. Ann Clin Transl Neurol 2020; 7:1908-1918. [PMID: 32945121 PMCID: PMC7545586 DOI: 10.1002/acn3.51184] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 01/04/2023] Open
Abstract
Objective Pure autonomic failure (PAF) is a rare disease characterized by neurogenic orthostatic hypotension (nOH), absence of signs of central neurodegeneration, and profound deficiency of the sympathetic neurotransmitter norepinephrine. Reports have disagreed about mechanisms of the noradrenergic lesion. Neuropathological studies have highlighted denervation, while functional studies have emphasized deficient vesicular sequestration of cytoplasmic catecholamines in extant neurons. We examined both aspects by a combined positron emission tomographic (PET) neuroimaging approach using 11C‐methylreboxetine (11C‐MRB), a selective ligand for the cell membrane norepinephrine transporter, to quantify interventricular septal myocardial noradrenergic innervation and using 18F‐dopamine (18F‐DA) to assess intraneuronal vesicular storage in the same subjects. Methods Seven comprehensively tested PAF patients and 11 controls underwent 11C‐MRB PET scanning for 45 minutes (dynamic 5X1’, 3X5’, 1X10’, static 15 minutes) and 18F‐DA scanning for 30 minutes (same dynamic imaging sequence) after 3‐minute infusions of the tracers on separate days. Results In the PAF group septal 11C‐MRB‐derived radioactivity in the static frame was decreased by 26.7% from control (p = 0.012). After adjustment for nonspecific binding of 11C‐MRB, the PAF group had a 41.1% mean decrease in myocardial 11C‐MRB‐derived radioactivity (p = 0.015). The PAF patients had five times faster postinfusion loss of 18F‐DA‐derived radioactivity (70 ± 3% vs. 14 ± 8% by 30 minutes, p < 0.0001). At all time points after infusion of 18F‐DA and 11C‐MRB mean 18F/11C ratios in septal myocardium were lower in the PAF than control group. Interpretation PAF entails moderately decreased cardiac sympathetic innervation and a substantial vesicular storage defect in residual nerves.
Collapse
Affiliation(s)
- David S Goldstein
- Autonomic Medicine Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Risa Isonaka
- Autonomic Medicine Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Courtney Holmes
- Autonomic Medicine Section, Clinical Neurosciences Program, Division of Intramural Research, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD
| | - Yu-Shin Ding
- Department of Radiology, New York University Langone Medical Center, New York, NY
| | - Yehonatan Sharabi
- Department of Internal Medicine, Chaim Sheba Medical Center, Tel Aviv University Sackler Faculty of Medicine, Tel Aviv, Israel
| |
Collapse
|
6
|
Grassi G, Quarti-Trevano F, Esler MD. Sympathetic activation in congestive heart failure: an updated overview. Heart Fail Rev 2019; 26:173-182. [PMID: 31832833 DOI: 10.1007/s10741-019-09901-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Conclusive evidence demonstrates that the sympathetic nervous system activation is a hallmark of congestive heart failure. This has been shown via a variety of biochemical, neurophysiological, and neuroimaging approaches for studying human sympathetic neural function. The sympathetic activation appears to be an early phenomenon in the clinical course of the disease, closely related to its severity and potentiated by the concomitant presence of other comorbidities, such as obesity, diabetes mellitus, metabolic syndrome, hypertension, and renal failure. The adrenergic overdrive in heart failure is associated with other sympathetic abnormalities, such as the downregulation of beta-adrenergic adrenoreceptors at cardiac level, and exerts unfavorable consequences on the cardiovascular system. These include the endothelial dysfunction, the development of left ventricular hypertrophy, the atherosclerosis development, as well as the generation of atrial and ventricular arrhythmias, and, at very extreme levels of sympathetic activation, the occurrence of microscopic myocardial necrosis. Given the close direct independent relationships detected in heart failure between sympathetic activation and mortality, the adrenergic overdrive has become a target of neuromodulatory therapeutic interventions, which include non-pharmacological, pharmacological, and device-based interventions. For some of these approaches (specifically bilateral renal nerves ablation and carotid baroreceptor stimulation), additional studies are needed to better define their impact on the clinical course of the disease.
Collapse
Affiliation(s)
- Guido Grassi
- Clinica Medica, Department of Medicine and Surgery, University of Milano-Bicocca, Via Pergolesi 33, 20052, Monza, Italy.
| | - Fosca Quarti-Trevano
- Clinica Medica, Department of Medicine and Surgery, University of Milano-Bicocca, Via Pergolesi 33, 20052, Monza, Italy
| | - Murray D Esler
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| |
Collapse
|
7
|
Raffel DM, Jung YW, Koeppe RA, Jang KS, Gu G, Scott PJH, Murthy VL, Rothley J, Frey KA. First-in-Human Studies of [ 18F] Fluorohydroxyphenethylguanidines. Circ Cardiovasc Imaging 2019; 11:e007965. [PMID: 30558502 DOI: 10.1161/circimaging.118.007965] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Disease-induced damage to cardiac autonomic nerve populations is associated with an increased risk of sudden cardiac death. The extent of cardiac sympathetic denervation, assessed using planar scintigraphy or positron emission tomography, has been shown to predict the risk of arrhythmic events in heart failure patients staged for implantable cardioverter defibrillator therapy. The goal of this study was to perform first-in-human evaluations of 4-[18F]fluoro-meta-hydroxyphenethylguanidine and 3-[18F]fluoro-para-hydroxyphenethylguanidine, 2 new positron emission tomography radiotracers developed for quantifying regional cardiac sympathetic nerve density. METHODS AND RESULTS Cardiac positron emission tomography studies with 4-[18F]fluoro-meta-hydroxyphenethylguanidine and 3-[18F]fluoro-para-hydroxyphenethylguanidine were performed in normal subjects (n=4 each) to assess their imaging properties and organ kinetics. Patlak graphical analysis of their myocardial kinetics was evaluated as a technique for generating nerve density metrics. Whole-body biodistribution studies (n=4 each) were acquired and used to calculate human radiation dosimetry estimates. Patlak analysis proved to be an effective approach for quantifying regional nerve density. Using 960 left ventricular volumes of interest, across-subject Patlak slopes averaged 0.107±0.010 mL/min per gram for 4-[18F]fluoro-meta-hydroxyphenethylguanidine and 0.116±0.010 mL/min per gram for 3-[18F]fluoro-para-hydroxyphenethylguanidine. Tracer uptake was highest in heart, liver, kidneys, and salivary glands. Urinary excretion was the main elimination pathway. CONCLUSIONS 4-[18F]fluoro-meta-hydroxyphenethylguanidine and 3-[18F]fluoro-para-hydroxyphenethylguanidine each produce high-quality positron emission tomography images of the distribution of sympathetic nerves in human heart. Patlak analysis provides reproducible measurements of regional cardiac sympathetic nerve density at high spatial resolution. Further studies of these tracers in heart failure patients will be performed to identify the best agent for clinical development. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov . Unique identifier: NCT02385877.
Collapse
Affiliation(s)
- David M Raffel
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Yong-Woon Jung
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Robert A Koeppe
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Keun Sam Jang
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Guie Gu
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Peter J H Scott
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Venkatesh L Murthy
- Division of Cardiovascular Medicine, Department of Internal Medicine, Frankel Cardiovascular Center, University of Michigan Medical School, Ann Arbor (V.L.M.)
| | - Jill Rothley
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| | - Kirk A Frey
- Division of Nuclear Medicine, Department of Radiology, University of Michigan Medical School (D.M.R., Y.-W.J., R.A.K., K.S.J., G.G., P.J.H.S., J.R., K.A.F.)
| |
Collapse
|
8
|
Abstract
PURPOSE OF REVIEW Patients with Parkinson's disease (PD) often display gastrointestinal and genitourinary autonomic symptoms years or even decades prior to diagnosis. These symptoms are thought to be caused in part by pathological α-synuclein inclusions in the peripheral autonomic and enteric nervous systems. It has been proposed that the initial α-synuclein aggregation may in some PD patients originate in peripheral nerve terminals and then spread centripetally to the spinal cord and brainstem. In vivo imaging methods can directly quantify the degeneration of the autonomic nervous system as well as the functional consequences such as perturbed motility. Here, we review the methodological principles of these imaging techniques and the major findings in patients with PD and atypical parkinsonism. RECENT FINDINGS Loss of sympathetic and parasympathetic nerve terminals in PD can be visualized using radiotracer imaging, including 123I-MIBG scintigraphy, and 18F-dopamine and 11C-donepezil PET. Recently, ultrasonographical studies disclosed reduced diameter of the vagal nerves in PD patients. Radiological and radioisotope techniques have demonstrated dysmotility and prolonged transit time throughout all subdivisions of the gastrointestinal tract in PD. The prevalence of objective dysfunction as measured with these imaging methods is often considerably higher compared to the prevalence of subjective symptoms experienced by the patients. Degeneration of the autonomic nervous system may play a key role in the pathogenesis of PD. In vivo imaging techniques provide powerful and noninvasive tools to quantify the degree and extent of this degeneration and its functional consequences.
Collapse
Affiliation(s)
- Karoline Knudsen
- Department of Nuclear Medicine and PET Centre Aarhus University Hospital, Institute of Clinical Medicine Aarhus University, Norrebrogade 44, Building 10, 8000, Aarhus C, Denmark
| | - Per Borghammer
- Department of Nuclear Medicine and PET Centre Aarhus University Hospital, Institute of Clinical Medicine Aarhus University, Norrebrogade 44, Building 10, 8000, Aarhus C, Denmark.
| |
Collapse
|
9
|
Roles of cardiac sympathetic neuroimaging in autonomic medicine. Clin Auton Res 2018; 28:397-410. [PMID: 30062642 DOI: 10.1007/s10286-018-0547-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 07/07/2018] [Indexed: 01/18/2023]
Abstract
Sympathetic neuroimaging is based on the injection of compounds that either radiolabel sites of the cell membrane norepinephrine transporter (NET) or that are taken up into sympathetic nerves via the NET and radiolabel intra-neuronal catecholamine storage sites. Detection of the radioactivity is by planar or tomographic radionuclide imaging. The heart stands out among body organs in terms of the intensity of radiolabeling of sympathetic nerves, and virtually all of sympathetic neuroimaging focuses on the left ventricular myocardium. The most common cardiac sympathetic neuroimaging method worldwide is 123I-metaiodobenzylguanidine (123I-MIBG) scanning. 123I-MIBG scanning is used routinely in Europe and East Asia in the diagnostic evaluation of neurogenic orthostatic hypotension (nOH), to distinguish Lewy body diseases (e.g., Parkinson disease with orthostatic hypotension (OH), pure autonomic failure) from non-Lewy body diseases (e.g., multiple system atrophy) and to distinguish dementia with Lewy bodies from Alzheimer's disease. In the USA, 123I-MIBG scanning has been approved by the Food and Drug Administration for the evaluation of pheochromocytoma and some forms of heart failure-but not for the above-mentioned differential diagnoses. Positron emission tomographic methods based on imaging agents such as 18F-dopamine are categorized as research tools, despite more than a quarter century of clinical experience with these modalities. Considering that 123I-MIBG scanning is available at most academic medical centers in the USA, cardiac sympathetic neuroimaging by this methodology merits consideration as an autonomic test, especially in patients with nOH.
Collapse
|
10
|
Langston JW, Wiley JC, Tagliati M. Optimizing Parkinson's disease diagnosis: the role of a dual nuclear imaging algorithm. NPJ PARKINSONS DISEASE 2018; 4:5. [PMID: 29507872 PMCID: PMC5824845 DOI: 10.1038/s41531-018-0041-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 01/08/2018] [Accepted: 02/01/2018] [Indexed: 12/11/2022]
Abstract
The diagnosis of Parkinson's disease (PD) currently relies almost exclusively on the clinical judgment of an experienced neurologist, ideally a specialist in movement disorders. However, such clinical diagnosis is often incorrect in a large percentage of patients, particularly in the early stages of the disease. A commercially available, objective and quantitative marker of nigrostriatal neurodegeneration was recently provided by 123-iodine 123I-ioflupane SPECT imaging, which is however unable to differentiate PD from a variety of other parkinsonian syndromes associated with striatal dopamine deficiency. There is evidence to support an algorithm utilizing a dual neuroimaging strategy combining 123I-ioflupane SPECT and the noradrenergic receptor ligand 123I-metaiodobenzylguanidine (MIBG), which assesses the post-ganglion peripheral autonomic nervous system. Evolving concepts regarding the synucleinopathy affecting the central and peripheral autonomic nervous systems as part of a multisystem disease are reviewed to sustain such strategy. Data are presented to show how MIBG deficits are a common feature of multisystem Lewy body disease and can be used as a unique feature to distinguish PD from atypical parkinsonisms. We propose that the combination of cardiac (MIBG) and cerebral 123I-ioflupane SPECT could satisfy one of the most significant unmet needs of current PD diagnosis and management, namely the early and accurate diagnosis of patients with typical Lewy body PD. Exemplary case scenarios will be described, highlighting how dual neuroimaging strategy can maximize diagnostic accuracy for patient care, clinical trials, pre-symptomatic PD screening, and special cases provided by specific genetic mutations associated with PD.
Collapse
Affiliation(s)
| | - Jesse C Wiley
- 2Department of Comparative Medicine, University of Washington, 1959 NE Pacific Ave Seattle, Seattle, WA USA
| | - Michele Tagliati
- Department of Neurology, Cedar-Sinai Medical Center, 127 S San Vicente Blvd, AHSP 6600, Los Angeles, CA 90272 USA
| |
Collapse
|
11
|
Borghammer P, Knudsen K, Fedorova TD, Brooks DJ. Imaging Parkinson's disease below the neck. NPJ Parkinsons Dis 2017; 3:15. [PMID: 28649615 PMCID: PMC5460119 DOI: 10.1038/s41531-017-0017-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 12/21/2016] [Accepted: 03/21/2017] [Indexed: 01/18/2023] Open
Abstract
Parkinson's disease is a systemic disorder with widespread and early α-synuclein pathology in the autonomic and enteric nervous systems, which is present throughout the gastrointestinal canal prior to diagnosis. Gastrointestinal and genitourinary autonomic symptoms often predate clinical diagnosis by several years. It has been hypothesized that progressive α-synuclein aggregation is initiated in hyperbranched, non-myelinated neuron terminals, and may subsequently spread via retrograde axonal transport. This would explain why autonomic nerves are so prone to formation of α-synuclein pathology. However, the hypothesis remains unproven and in vivo imaging methods of peripheral organs may be essential to study this important research field. The loss of sympathetic and parasympathetic nerve terminal function in Parkinson's disease has been demonstrated using radiotracers such as 123I-meta-iodobenzylguanidin, 18F-dopamine, and 11C-donepezil. Other radiotracer and radiological imaging methods have shown highly prevalent dysfunction of pharyngeal and esophageal motility, gastric emptying, colonic transit time, and anorectal function. Here, we summarize the methodology and main findings of radio-isotope and radiological modalities for imaging peripheral pathology in Parkinson's disease.
Collapse
Affiliation(s)
- Per Borghammer
- Department of Nuclear Medicine & PET Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Karoline Knudsen
- Department of Nuclear Medicine & PET Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Tatyana D. Fedorova
- Department of Nuclear Medicine & PET Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - David J. Brooks
- Department of Nuclear Medicine & PET Centre, Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Division of Neuroscience, Department of Medicine, Imperial College London, London, UK
- Division of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
| |
Collapse
|
12
|
Assessment of diabetic neuropathy with emission tomography and magnetic resonance spectroscopy. Nucl Med Commun 2017; 38:275-284. [DOI: 10.1097/mnm.0000000000000653] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Howden EJ, Lawley JS, Esler M, Levine BD. Potential role of endurance training in altering renal sympathetic nerve activity in CKD? Auton Neurosci 2016; 204:74-80. [PMID: 27908698 DOI: 10.1016/j.autneu.2016.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 11/16/2016] [Accepted: 11/23/2016] [Indexed: 12/20/2022]
Abstract
Chronic kidney disease (CKD), is characterized by a progressive loss of renal function and increase in cardiovascular risk. In this review paper, we discuss the pathophysiology of increased sympathetic nerve activity in CKD patients and raise the possibility of endurance exercise being an effective countermeasure to address this problem. We specifically focus on the potential role of endurance training in altering renal sympathetic nerve activity as increased renal sympathetic nerve activity negatively impacts kidney function as well indirectly effects multiple other systems and organs. Recent technological advances in device based therapy have highlighted the detrimental effect of elevated renal sympathetic nerve activity in CKD patients, with kidney function and blood pressure being improved post renal artery nerve denervation in selected patients. These developments provide optimism for the development of alternative and/or complementary strategies to lower renal sympathetic nerve activity. However, appropriately designed studies are required to confirm preliminary observations, as the widespread use of the renal denervation approach to lower sympathetic activity presently has limited feasibility. Endurance training may be one alternative strategy to reduce renal sympathetic nerve activity. Here we review the role of endurance training as a potential alternative or adjunctive to current therapy in CKD patients. We also provide recommendations for future research to assist in establishing an evidence base for the use of endurance training to lower renal sympathetic activity in CKD patients.
Collapse
Affiliation(s)
- Erin J Howden
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX 75231, United States; University of Texas Southwestern Medical Center, Dallas, TX 75231, United States; Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia.
| | - Justin S Lawley
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX 75231, United States; University of Texas Southwestern Medical Center, Dallas, TX 75231, United States
| | - Murray Esler
- Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX 75231, United States; University of Texas Southwestern Medical Center, Dallas, TX 75231, United States
| |
Collapse
|
14
|
Harms HJ, Huisman MC, Rijnierse MT, Greuter H, Hsieh YL, de Haan S, Schuit RC, Knaapen P, Lubberink M, Lammertsma AA. Noninvasive Quantification of Myocardial 11C-Meta-Hydroxyephedrine Kinetics. J Nucl Med 2016; 57:1376-81. [PMID: 27230922 DOI: 10.2967/jnumed.115.167437] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 03/01/2016] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED (11)C-meta-hydroxyephedrine ((11)C-HED) kinetics in the myocardium can be quantified using a single-tissue-compartment model together with a metabolite-corrected arterial blood sampler input function (BSIF). The need for arterial blood sampling, however, limits clinical applicability. The purpose of this study was to investigate the feasibility of replacing arterial sampling with imaging-derived input function (IDIF) and venous blood samples. METHODS Twenty patients underwent 60-min dynamic (11)C-HED PET/CT scans with online arterial blood sampling. Thirteen of these patients also underwent venous blood sampling. Data were reconstructed using both 3-dimensional row-action maximum-likelihood algorithm (3DR) and a time-of-flight (TF) list-mode reconstruction algorithm. For each reconstruction, IDIF results were compared with BSIF results. In addition, IDIF results obtained with venous blood samples and with a transformed venous-to-arterial metabolite correction were compared with results obtained with arterial metabolite corrections. RESULTS Correlations between IDIF- and BSIF-derived K1 and VT were high (r(2) > =0.89 for 3DR and TF). Slopes of the linear fits were significantly different from 1 for K1, for both 3DR (slope = 0.94) and TF (slope = 1.06). For VT, the slope of the linear fit was different from 1 for TF (slope = 0.93) but not for 3DR (slope = 0.98). Use of venous blood data introduced a large bias in VT (r(2) = 0.96, slope = 0.84) and a small bias in K1 (r(2) = 0.99, slope = 0.98). Use of a second-order polynomial venous-to-arterial transformation was robust and greatly reduced bias in VT (r(2) = 0.97, slope = 0.99) with no effect on K1 CONCLUSION: IDIF yielded precise results for both 3DR and TF. Venous blood samples can be used for absolute quantification of (11)C-HED studies, provided a venous-to-arterial transformation is applied. A venous-to-arterial transformation enables noninvasive, absolute quantification of (11)C-HED studies.
Collapse
Affiliation(s)
- Hendrik J Harms
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Marc C Huisman
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Mischa T Rijnierse
- Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Henri Greuter
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | | | - Stefan de Haan
- Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Robert C Schuit
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Paul Knaapen
- Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Mark Lubberink
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands Nuclear Medicine and PET, Uppsala University, Akademiska sjukhuset, Uppsala, Sweden
| | - Adriaan A Lammertsma
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| |
Collapse
|
15
|
Borghammer P, Knudsen K, Brooks DJ. Imaging Systemic Dysfunction in Parkinson’s Disease. Curr Neurol Neurosci Rep 2016; 16:51. [DOI: 10.1007/s11910-016-0655-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
16
|
Neumann KD, Qin L, Vāvere AL, Shen B, Miao Z, Chin FT, Shulkin BL, Snyder SE, DiMagno SG. Efficient automated syntheses of high specific activity 6-[18F]fluorodopamine using a diaryliodonium salt precursor. J Labelled Comp Radiopharm 2016; 59:30-4. [PMID: 26695865 PMCID: PMC4715522 DOI: 10.1002/jlcr.3367] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 11/08/2022]
Abstract
6-[(18)F]Fluorodopamine (6-[(18) F]F-DA) is a positron emission tomography radiopharmaceutical used to image sympathetic cardiac innervation and neuroendocrine tumors. Imaging with 6-[(18)F]F-DA is constrained, in part, by the bioactivity and neurotoxicity of 6-[(19)F]fluorodopamine. Furthermore, routine access to this radiotracer is limited by the inherent difficulty of incorporation of [(18)F]fluoride into electron-rich aromatic substrates. We describe the simple and direct preparation of high specific activity (SA) 6-[(18)F]F-DA from no-carrier-added (n.c.a.) [(18)F]fluoride. Incorporation of n.c.a. [(18)F]fluoride into a diaryliodonium salt precursor was achieved in 50-75% radiochemical yields (decay corrected to end of bombardment). Synthesis of 6-[(18)F]F-DA on the IBA Synthera® and GE TRACERlab FX-FN automated platforms gave 6-[(18)F]F-DA in >99% chemical and radiochemical purities after HPLC purification. The final non-corrected yields of 6-[(18)F]F-DA were 25 ± 4% (n = 4, 65 min) and 31 ± 6% (n = 3, 75 min) using the Synthera and TRACERlab modules, respectively. Efficient access to high SA 6-[(18)F]F-DA from a diaryliodonium salt precursor and n.c.a. [(18)F]fluoride is provided by a relatively subtle change in reaction conditions - replacement of a polar aprotic solvent (acetonitrile) with a relatively nonpolar solvent (toluene) during the critical radiofluorination reaction. Implementation of this process on common radiochemistry platforms should make 6-[(18)F]F-DA readily available to the wider imaging community.
Collapse
Affiliation(s)
- Kiel D. Neumann
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Linlin Qin
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Amy L. Vāvere
- Division of Nuclear Medicine, Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee
| | - Bin Shen
- Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Zheng Miao
- Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Frederick T. Chin
- Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Barry L. Shulkin
- Division of Nuclear Medicine, Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee
| | - Scott E. Snyder
- Division of Nuclear Medicine, Department of Radiological Sciences, St. Jude Children’s Research Hospital, Memphis, Tennessee
| | - Stephen G. DiMagno
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska
| |
Collapse
|
17
|
Role of the autonomic nervous system in activation of human brown adipose tissue: A review of the literature. DIABETES & METABOLISM 2015; 41:437-45. [DOI: 10.1016/j.diabet.2015.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/21/2015] [Accepted: 08/28/2015] [Indexed: 11/17/2022]
|
18
|
|
19
|
Harms HJ, Lubberink M, de Haan S, Knaapen P, Huisman MC, Schuit RC, Windhorst AD, Allaart CP, Lammertsma AA. Use of a Single 11C-Meta-Hydroxyephedrine Scan for Assessing Flow–Innervation Mismatches in Patients with Ischemic Cardiomyopathy. J Nucl Med 2015; 56:1706-11. [DOI: 10.2967/jnumed.115.154377] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 07/16/2015] [Indexed: 11/16/2022] Open
|
20
|
Harms HJ, de Haan S, Knaapen P, Allaart CP, Rijnierse MT, Schuit RC, Windhorst AD, Lammertsma AA, Huisman MC, Lubberink M. Quantification of [(11)C]-meta-hydroxyephedrine uptake in human myocardium. EJNMMI Res 2014; 4:52. [PMID: 26116116 PMCID: PMC4452641 DOI: 10.1186/s13550-014-0052-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 09/08/2014] [Indexed: 12/02/2022] Open
Abstract
Background The aims of this study were to determine the optimal tracer kinetic model for [11C]-meta-hydroxyephedrine ([11C]HED) and to evaluate the performance of several simplified methods. Methods Thirty patients underwent dynamic 60-min [11C]HED scans with online arterial blood sampling. Single-tissue and both reversible and irreversible two-tissue models were fitted to the data using the metabolite-corrected arterial input function. For each model, reliable fits were defined as those yielding outcome parameters with a coefficient of variation (CoV) <25%. The optimal model was determined using Akaike and Schwarz criteria and the F-test, together with the number of reliable fits. Simulations were performed to study accuracy and precision of each model. Finally, quantitative results obtained using a population-averaged metabolite correction were evaluated, and simplified retention index (RI) and standardized uptake value (SUV) results were compared with quantitative volume of distribution (VT) data. Results The reversible two-tissue model was preferred in 75.8% of all segments, based on the Akaike information criterion. However, VT derived using the single-tissue model correlated highly with that of the two-tissue model (r2 = 0.94, intraclass correlation coefficient (ICC) = 0.96) and showed higher precision (CoV of 24.6% and 89.2% for single- and two-tissue models, respectively, at 20% noise). In addition, the single-tissue model yielded reliable fits in 94.6% of all segments as compared with 77.1% for the reversible two-tissue model. A population-averaged metabolite correction could not be used in approximately 20% of the patients because of large biases in VT. RI and SUV can provide misleading results because of non-linear relationships with VT. Conclusions Although the reversible two-tissue model provided the best fits, the single-tissue model was more robust and results obtained were similar. Therefore, the single-tissue model was preferred. RI showed a non-linear correlation with VT, and therefore, care has to be taken when using RI as a quantitative measure. Electronic supplementary material The online version of this article (doi:10.1186/s13550-014-0052-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Hendrik J Harms
- Department of Radiology and Nuclear Medicine, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, the Netherlands,
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Heathers JAJ. Everything Hertz: methodological issues in short-term frequency-domain HRV. Front Physiol 2014; 5:177. [PMID: 24847279 PMCID: PMC4019878 DOI: 10.3389/fphys.2014.00177] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 04/17/2014] [Indexed: 11/22/2022] Open
Abstract
Frequency analysis of the electrocardiographic RR interval is a common method of quantifying autonomic outflow by measuring the beat-to-beat modulation of the heart (heart rate variability; HRV). This review identifies a series of problems with the methods of doing so—the interpretation of low-frequency spectral power, the multiple use of equivalent normalized low frequency (LFnu), high frequency (HFnu) and ratio (LF/HF) terms, and the lack of control over extraneous variables, and reviews research in the calendar year 2012 to determine their prevalence and severity. Results support the mathematical equivalency of ratio units across studies, a reliance on those variables to explain autonomic outflow, and insufficient control of critical experimental variables. Research measurement of HRV has a substantial need for general methodological improvement.
Collapse
Affiliation(s)
- James A J Heathers
- Psychophysiology Group, Department of Psychology, University of Sydney Sydney, NSW, Australia
| |
Collapse
|
22
|
Peripheral autonomic neuropathy: diagnostic contribution of skin biopsy. J Neuropathol Exp Neurol 2013; 71:1000-8. [PMID: 23037327 DOI: 10.1097/nen.0b013e3182729fdc] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Skin biopsy has gained widespread use for the diagnosis of somatic small-fiber neuropathy, but it also provides information on sympathetic fiber morphology. We aimed to ascertain the diagnostic accuracy of skin biopsy in disclosing sympathetic nerve abnormalities in patients with autonomic neuropathy. Peripheral nerve fiber autonomic involvement was confirmed by routine autonomic laboratory test abnormalities. Punch skin biopsies were taken from the thigh and lower leg of 28 patients with various types of autonomic neuropathy for quantitative evaluation of skin autonomic innervation. Results were compared with scores obtained from 32 age-matched healthy controls and 25 patients with somatic neuropathy. The autonomic cutoff score was calculated using the receiver operating characteristic curve analysis. Skin biopsy disclosed a significant autonomic innervation decrease in autonomic neuropathy patients versus controls and somatic neuropathy patients. Autonomic innervation density was abnormal in 96% of patients in the lower leg and in 79% of patients in the thigh. The abnormal findings disclosed by routine autonomic tests ranged from 48% to 82%. These data indicate the high sensitivity and specificity of skin biopsy in detecting sympathetic abnormalities; this method should be useful for the diagnosis of autonomic neuropathy, together with currently available routine autonomic testing.
Collapse
|
23
|
Al-Momani E, Zlatopolskiy BD, Machulla HJ, Reske SN, Solbach C. Radiosynthesis of carbon-11 labeled 6-methyldopamine ([¹¹C]MeDA). Appl Radiat Isot 2012; 70:1475-9. [PMID: 22728836 DOI: 10.1016/j.apradiso.2012.04.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Revised: 04/17/2012] [Accepted: 04/19/2012] [Indexed: 11/15/2022]
Abstract
A rapid and efficient n.c.a. radiosynthesis of 6-[(11)C]methyldopamine ([(11)C]MeDA) using the Stille cross-coupling reaction as a key step was developed. The labeling conditions for the formation of the intermediate compound (protected [(11)C]MeDA, [(11)C]7) were determined with respect to reaction temperature and time. The radiochemical yield 89 ± 1.4% (decay-corrected) of the protected intermediate [(11)C]7 was obtained at a reaction temperature of 60°C and a reaction time of 5 min using Pd(2)(dba)(3)/P(o-tolyl)(3) and CsF/CuBr as a co-catalyst system. The overall yield after deprotection with 45% HBr at 140°C for 10 min was 64 ± 3.9% (decay-corrected) within a total preparation time of 40 min, including hydrolysis, HPLC purification and formulation.
Collapse
Affiliation(s)
- E Al-Momani
- Clinic for Nuclear Medicine, University Ulm, Germany
| | | | | | | | | |
Collapse
|
24
|
Eskola O, Grönroos TJ, Naum A, Marjamäki P, Forsback S, Bergman J, Länkimäki S, Kiss J, Savunen T, Knuuti J, Haaparanta M, Solin O. Novel electrophilic synthesis of 6-[18F]fluorodopamine and comprehensive biological evaluation. Eur J Nucl Med Mol Imaging 2012; 39:800-10. [DOI: 10.1007/s00259-011-2032-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 12/08/2011] [Indexed: 10/14/2022]
|
25
|
Goldstein DS. Patients as a scientific resource: comments on receiving the Ahrens award. Clin Transl Sci 2011; 4:231-2. [PMID: 21884507 DOI: 10.1111/j.1752-8062.2011.00311.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
26
|
Microneurographic evaluation of sympathetic activity in small fiber neuropathy. Clin Neurophysiol 2011; 122:1854-9. [DOI: 10.1016/j.clinph.2011.02.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 02/09/2011] [Accepted: 02/18/2011] [Indexed: 02/01/2023]
|
27
|
Cardiac positron emission tomography. J Am Coll Cardiol 2009; 54:1-15. [PMID: 19555834 DOI: 10.1016/j.jacc.2009.02.065] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Revised: 01/27/2009] [Accepted: 02/23/2009] [Indexed: 11/23/2022]
Abstract
Positron emission tomography (PET) is a powerful, quantitative imaging modality that has been used for decades to noninvasively investigate cardiovascular biology and physiology. Due to limited availability, methodologic complexity, and high costs, it has long been seen as a research tool and as a reference method for validation of other diagnostic approaches. This perception, fortunately, has changed significantly within recent years. Increasing diversity of therapeutic options for coronary artery disease, and increasing specificity of novel therapies for certain biologic pathways, has resulted in a clinical need for more accurate and specific diagnostic techniques. At the same time, the number of PET centers continues to grow, stimulated by PET's success in oncology. Methodologic advances as well as improved radiotracer availability have further contributed to more widespread use. Evidence for diagnostic and prognostic usefulness of myocardial perfusion and viability assessment by PET is increasing. Some studies suggest overall cost-effectiveness of the technique despite higher costs of a single study, because unnecessary follow-up procedures can be avoided. The advent of hybrid PET-computed tomography (CT), which enables integration of PET-derived biologic information with multislice CT-derived morphologic information, and the key role of PET in the development and translation of novel molecular-targeted imaging compounds, have further contributed to more widespread acceptance. Today, PET promises to play a leading diagnostic role on the pathway toward a future of high-powered, comprehensive, personalized, cardiovascular medicine. This review summarizes the state-of-the-art in current imaging methodology and clinical application, and outlines novel developments and future directions.
Collapse
|
28
|
Henneman MM, Bengel FM, van der Wall EE, Knuuti J, Bax JJ. Cardiac neuronal imaging: application in the evaluation of cardiac disease. J Nucl Cardiol 2008; 15:442-55. [PMID: 18513651 DOI: 10.1016/j.nuclcard.2008.02.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Maureen M Henneman
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | | | | | | | | |
Collapse
|
29
|
|
30
|
Lautamäki R, Tipre D, Bengel FM. Cardiac sympathetic neuronal imaging using PET. Eur J Nucl Med Mol Imaging 2007; 34 Suppl 1:S74-85. [PMID: 17479262 DOI: 10.1007/s00259-007-0442-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
INTRODUCTION Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET AS AN IMAGING TOOL PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. REVIEW This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed.
Collapse
Affiliation(s)
- Riikka Lautamäki
- Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA
| | | | | |
Collapse
|
31
|
Raffel DM, Jung YW, Gildersleeve DL, Sherman PS, Moskwa JJ, Tluczek LJ, Chen W. Radiolabeled phenethylguanidines: novel imaging agents for cardiac sympathetic neurons and adrenergic tumors. J Med Chem 2007; 50:2078-88. [PMID: 17419605 PMCID: PMC2625310 DOI: 10.1021/jm061398y] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The norepinephrine transporter (NET) substrates [123I]-m-iodobenzylguanidine (MIBG) and [11C]-m-hydroxyephedrine (HED) are used as markers of cardiac sympathetic neurons and adrenergic tumors (pheochromocytoma, neuroblastoma). However, their rapid NET transport rates limit their ability to provide accurate measurements of cardiac nerve density. [11C]Phenethylguanidine ([11C]1a) and 12 analogues ([11C]1b-m) were synthesized and evaluated as radiotracers with improved kinetics for quantifying cardiac nerve density. In isolated rat hearts, neuronal uptake rates of [11C]1a-m ranged from 0.24 to 1.96 mL min-1 (g wet wt)-1, and six compounds had extremely long neuronal retention times (clearance T1/2 > 20 h) due to efficient vesicular storage. Positron emission tomography (PET) studies in nonhuman primates with [11C]1e, N-[11C]guanyl-m-octopamine, which has a slow NET transport rate, showed improved myocardial kinetics compared to HED. Compound [11C]1c, [11C]-p-hydroxyphenethylguanidine, which has a rapid NET transport rate, avidly accumulated into rat pheochromocytoma xenograft tumors in mice. These encouraging findings demonstrate that radiolabeled phenethylguanidines deserve further investigation as radiotracers of cardiac sympathetic innervation and adrenergic tumors.
Collapse
Affiliation(s)
- David M Raffel
- Division of Nuclear Medicine, Department of Radiology, 3480 Kresge III Building, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA.
| | | | | | | | | | | | | |
Collapse
|
32
|
Namavari M, Satyamurthy N, Barrio JR. Synthesis of 6-[18F]fluorodopamine, 6-[18F]fluoro-m-tyramine and 4-[18F]fluoro-m-tyramine+. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580360903] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
33
|
Mamede M, Carrasquillo JA, Chen CC, Del Corral P, Whatley M, Ilias I, Ayala A, Pacak K. Discordant localization of 2-[18F]-fluoro-2-deoxy-D-glucose in 6-[18F]-fluorodopamine- and [123I]-metaiodobenzylguanidine-negative metastatic pheochromocytoma sites. Nucl Med Commun 2006; 27:31-6. [PMID: 16340721 DOI: 10.1097/01.mnm.0000189780.54658.e8] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Although the majority of pheochromocytomas (PHEO) are benign, a subset is malignant. Computed tomography (CT) and magnetic resonance imaging (MRI) localize PHEO with high sensitivity but, because of limited specificity, [(131)I]- or [(123)I]-metaiodobenzylguanidine ([(131)I]- or [(123)I]-MIBG) is often used as a complementary agent. 6-[18F]-fluorodopamine ([18F]-DA) has been developed as a radiopharmaceutical for the targeting of noradrenergic pathways, and has been shown to result in a better detection rate of PHEO sites than MIBG; however, [18F]-DA has shown a lack of accumulation in some patients with metastatic PHEO. METHODS Five patients with widespread metastatic PHEO who had CT and MRI evidence of metastatic disease (one man and four women; age range, 25-64 years), and who underwent imaging with [(123)I]-MIBG, [18F]-DA and 2-[18F]-fluoro-2-deoxy-D-glucose ([18F]-FDG), were evaluated retrospectively. Tomographic imaging was performed and positron emission tomography (PET) images were inspected visually and quantitatively. RESULTS All five patients had [(123)I]-MIBG scans that grossly underestimated the extent of disease when compared with conventional CT and MRI. All lesions seen on [(123)I]-MIBG scans were detected on [18F]-DA scans, which also detected additional lesions. Nonetheless, [18F]-DA also failed to detect numerous lesions seen on CT and MRI. In all of these cases, [18F]-FDG PET showed lesions that were not detected on either [(123)I]-MIBG or [18F]-DA scans. CONCLUSIONS When [(123)I]-MIBG or [18F]-DA fails to localize lesions seen on conventional imaging studies, [18F]-FDG may be recommended as an ancillary test for the diagnosis and localization of metastatic PHEO. This is particularly important in patients with aggressive PHEO.
Collapse
Affiliation(s)
- Marcelo Mamede
- Nuclear Medicine Department, Clinical Center, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1109, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Moak JP, Eldadah B, Holmes C, Pechnik S, Goldstein DS. Partial cardiac sympathetic denervation after bilateral thoracic sympathectomy in humans. Heart Rhythm 2005; 2:602-9. [PMID: 15922266 DOI: 10.1016/j.hrthm.2005.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2005] [Accepted: 03/01/2005] [Indexed: 11/26/2022]
Abstract
BACKGROUND Upper thoracic sympathectomy is used to treat several disorders. Sympathetic nerve fibers emanating from thoracic ganglia innervate the heart. Whether unilateral or bilateral upper thoracic sympathectomy affects cardiac sympathetic innervation in humans in vivo has been unclear. OBJECTIVES The purpose of this study was to assess whether thoracic sympathectomy decreases cardiac sympathetic innervation, as indicated by positron emission tomographic scanning after intravenous injection of the sympathoneural imaging agent 6-[18F]fluorodopamine. METHODS Nine patients with previous upper thoracic sympathectomies (four right-sided, one left-sided, four bilateral) underwent thoracic 6-[18F]fluorodopamine scanning between 1 and 2 hours after injection of the imaging agent. In each case, a low rate of entry of norepinephrine into the arm venous drainage (norepinephrine spillover) verified upper limb sympathectomy. Data were compared with those from the interventricular septum of patients with cardiac sympathetic denervation associated with pure autonomic failure and from normal volunteers. RESULTS All four patients with bilateral sympathectomy had low septal myocardial 6-[18F]fluorodopamine-derived radioactivity (2,673 +/- 92 nCi-kg/cc-mCi at an average of 89 minutes after injection) compared with normal volunteers (3,634 +/- 311 nCi-kg/cc-mCi at 83 minutes, N = 22, P = .007) and higher radioactivity than in patients with pure autonomic failure (1,320 +/- 300 nCi-kg/cc-mCi at 83 minutes, N = 7, P = .003). Patients with unilateral sympathectomy had normal 6-[18F]fluorodopamine-derived radioactivity (3,971 +/- 337 nCi-kg/cc-mCi at 87 minutes). CONCLUSIONS Bilateral upper thoracic sympathectomy partly decreases cardiac sympathetic innervation density.
Collapse
Affiliation(s)
- Jeffrey P Moak
- Children's National Medical Center, Washington, DC, USA. moakj@ ninds.nih.gov
| | | | | | | | | |
Collapse
|
35
|
|
36
|
Abstract
The autonomic nervous system plays a key role for regulation of cardiac performance, and the importance of alterations of innervation in the pathophysiology of various heart diseases has been increasingly emphasized. Nuclear imaging techniques have been established that allow for global and regional investigation of the myocardial nervous system. The guanethidine analog iodine 123 metaiodobenzylguanidine (MIBG) has been introduced for scintigraphic mapping of presynaptic sympathetic innervation and is available today for imaging on a broad clinical basis. Not much later than MIBG, positron emission tomography (PET) has also been established for characterizing the cardiac autonomic nervous system. Although PET is methodologically demanding and less widely available, it provides substantial advantages. High spatial and temporal resolution along with routinely available attenuation correction allows for detailed definition of tracer kinetics and makes noninvasive absolute quantification a reality. Furthermore, a series of different radiolabeled catecholamines, catecholamine analogs, and receptor ligands are available. Those are often more physiologic than MIBG and well understood with regard to their tracer physiologic properties. PET imaging of sympathetic neuronal function has been successfully applied to gain mechanistic insights into myocardial biology and pathology. Available tracers allow dissection of processes of presynaptic and postsynaptic innervation contributing to cardiovascular disease. This review summarizes characteristics of currently available PET tracers for cardiac neuroimaging along with the major findings derived from their application in health and disease.
Collapse
Affiliation(s)
- Frank M Bengel
- Nuklearmedizinische Klinik der Technischen Universität Müchen, 81675 Munich, Germany.
| | | |
Collapse
|
37
|
Goldstein DS, Li ST, Holmes C, Bankiewicz K. Sympathetic innervation in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine primate model of Parkinson's disease. J Pharmacol Exp Ther 2003; 306:855-60. [PMID: 12805479 DOI: 10.1124/jpet.103.051714] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cardiac sympathetic denervation occurs commonly in Parkinson's disease. This study explored whether analogous denervation occurs in primates with Parkinsonism from systemic administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). 6-[18F]Fluorodopamine positron emission tomographic scanning and plasma levels of catecholamines and their deaminated metabolites were used to assess sympathetic and adrenomedullary function in rhesus monkeys, in the untreated state (n = 3), 2 weeks after a series of four MPTP injections, before establishment of Parkinsonism (acute phase, n = 1); a month later, after four more MPTP doses, associated with severe Parkinsonism (subacute phase, n = 1); or more than 2 years from the last dose (remote phase, n = 3), with persistent severe Parkinsonism. A positive control received i.v. 6-hydroxydopamine 1 week before 6-[18F]fluorodopamine scanning. Acute MPTP treatment increased cardiac 6-[18F]fluorodopamine-derived radioactivity, whereas 6-hydroxydopamine markedly decreased cardiac radioactivity, despite similarly low plasma levels of catecholamines and metabolites after either treatment. Subacutely, plasma catecholamines remained decreased, but now with myocardial 6-[18F]fluorodopamine-derived radioactivity also decreased. Remotely, MPTP-treated monkeys had lower plasma catecholamines and higher myocardial 6-[18F]fluorodopamine-derived radioactivity than did untreated animals. The results indicate that in nonhuman primates, systemic MPTP administration produces multiphasic effects on peripheral catecholamine systems, with nearly complete recovery by 2 years. MPTP- and 6-hydroxydopamine-induced changes differ markedly, probably from ganglionic or preganglionic neurotoxicity with the former and more severe cardiac sympathetic neurotoxicity with the latter. Because of multiphasic sympathetic and adrenomedullary effects, without cardioselective sympathetic denervation at any time, the primate MPTP model does not mimic the changes in peripheral catecholamine systems that characterize the human disease.
Collapse
Affiliation(s)
- David S Goldstein
- Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1620, USA.
| | | | | | | |
Collapse
|
38
|
Grassi G. Sympathetic deactivation as a goal of nonpharmacologic and pharmacologic antihypertensive treatment: rationale and options. Curr Hypertens Rep 2003; 5:277-80. [PMID: 12844461 DOI: 10.1007/s11906-003-0033-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Guido Grassi
- Clinica Medica, Università Milano-Bicocca, Via Donizetti 106, 20052 Monza (Mi), Italy.
| |
Collapse
|
39
|
Ding YS, Fowler JS. Highlights of PET studies on chiral radiotracers and drugs at Brookhaven. Drug Dev Res 2003. [DOI: 10.1002/ddr.10221] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
40
|
Esler M, Lambert G, Brunner-La Rocca HP, Vaddadi G, Kaye D. Sympathetic nerve activity and neurotransmitter release in humans: translation from pathophysiology into clinical practice. ACTA PHYSIOLOGICA SCANDINAVICA 2003; 177:275-84. [PMID: 12608997 DOI: 10.1046/j.1365-201x.2003.01089.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AIM There has been a revolution in cardiovascular neuroscience in recent years with, in some cases, translation into clinical practice of the knowledge of pathophysiology gained through application of sympathetic nerve recording and catecholamine isotope dilution methodology. OBESITY-RELATED HYPERTENSION: An earlier hypothesis, based on findings in most models, was that weight gain in obesity is due in part to sympathetic nervous underactivity reducing thermogenesis. Microneurography and regional noradrenaline spillover measurements in human obesity have disproven this hypothesis, weakening the case for the use of beta3-adrenergic agonists to stimulate thermogenesis. Sympathetic nerve firing rates in post-ganglionic fibres directed to the skeletal muscle vasculature are increased, as is renal sympathetic tone, with a doubling of the spillover rate of noradrenaline from the kidneys. Given these findings, antiadrenergic antihypertensive drugs may be the preferred agents for obesity-related hypertension, but this has not been adequately tested. ESSENTIAL HYPERTENSION Whether stress causes high blood pressure, previously hotly debated, has been under recent review by an Australian Government body, the Specialist Medical Review Council. Despite medicolegal implications, the ruling was that stress is one proven cause of hypertension. The judgment was reached after consideration of the epidemiological evidence, but in particular the described neural pathophysiology of essential hypertension: (a) persistent sympathetic nervous stimulation is commonly present, (b) suprabulbar projections of noradrenergic brainstem neurones are activated and (c) adrenaline is released as a cotransmitter in sympathetic nerves. These were taken to be biological markers of stress. CARDIAC FAILURE At one time, the failing heart was thought to be sympathetically denervated. Longterm administration of inotropic adrenergic agonists, to provide the cardiac catecholamine stimulation thought to be lacking, increased mortality. Noradrenaline isotope dilution methodology subsequently demonstrated that the sympathetic outflow to the heart was preferentially activated, cardiac noradrenaline spillover being increased as much as 50-fold. The level of stimulation of the cardiac sympathetic nerves was the most powerful predictor of death. These observations provide the theoretical foundation for the very successful introduction of beta-adrenergic blockers for treatment of heart failure.
Collapse
Affiliation(s)
- M Esler
- Baker Heart Research Institute, Prahran, Melbourne, Australia
| | | | | | | | | |
Collapse
|
41
|
Pacak K, Eisenhofer G, Carrasquillo JA, Chen CC, Whatley M, Goldstein DS. Diagnostic localization of pheochromocytoma: the coming of age of positron emission tomography. Ann N Y Acad Sci 2002; 970:170-6. [PMID: 12381552 DOI: 10.1111/j.1749-6632.2002.tb04423.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pheochromocytoma is a rare but clinically important tumor of catecholamine-secreting chromaffin cells. This tumor constitutes a surgically curable cause of hypertension. Therefore, correct localization of pheochromocytoma is essential for effective management of this tumor. Several conventional and nuclear imaging modalities are currently available to localize pheochromocytoma. Computed tomography (CT) and magnetic resonance imaging (MRI) have good sensitivity but poor specificity for detecting pheochromocytoma, and nuclear imaging approaches such as (131)I-metaiodobenzylguanidine scintigraphy or [(111)In]-DTPA-D-Phe-pentetreotide (Octreoscan) have limited sensitivity. However, specificity of (131)I-metaiodobenzylguanidine scintigraphy is very good and this means of imaging provides a method for confirming that a tumor is a pheochromocytoma and rules out metastatic disease. Recently, we introduced a new imaging method, 6-[(18)F]fluorodopamine positron emission tomography, that can be used successfully for the detection of solitary and metastatic pheochromocytomas. Our preliminary data suggest that this method is superior to other nuclear imaging methods including metaiodobenzylguanidine and octreotide scintigraphy. In this report we provide an update regarding nuclear imaging of primary and metastatic pheochromocytoma, particularly using 6-[(18)F]fluorodopamine positron emission tomographic scanning.
Collapse
Affiliation(s)
- Karel Pacak
- Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development/NIH, Building 10, Room 9D42, 10 Center Drive MSC 1583, Bethesda, MD 20892, USA.
| | | | | | | | | | | |
Collapse
|
42
|
Parikh SM, Diedrich A, Biaggioni I, Robertson D. The nature of the autonomic dysfunction in multiple system atrophy. J Neurol Sci 2002; 200:1-10. [PMID: 12127669 DOI: 10.1016/s0022-510x(02)00126-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The concept that multiple system atrophy (MSA, Shy-Drager syndrome) is a disorder of the autonomic nervous system is several decades old. While there has been renewed interest in the movement disorder associated with MSA, two recent consensus statements confirm the centrality of the autonomic disorder to the diagnosis. Here, we reexamine the autonomic pathophysiology in MSA. Whereas MSA is often thought of as "autonomic failure", new evidence indicates substantial persistence of functioning sympathetic and parasympathetic nerves even in clinically advanced disease. These findings help explain some of the previously poorly understood features of MSA. Recognition that MSA entails persistent, constitutive autonomic tone requires a significant revision of our concepts of its diagnosis and therapy. We will review recent evidence bearing on autonomic tone in MSA and discuss their therapeutic implications, particularly in terms of the possible development of a bionic baroreflex for better control of blood pressure.
Collapse
Affiliation(s)
- Samir M Parikh
- Autonomic Dysfunction Center, Department of Medicine, Vanderbilt University, AA 3228 MCN, Nashville, TN 37232-2195, USA
| | | | | | | |
Collapse
|
43
|
Raffel DM, Wieland DM. Assessment of cardiac sympathetic nerve integrity with positron emission tomography. Nucl Med Biol 2001; 28:541-59. [PMID: 11516699 DOI: 10.1016/s0969-8051(01)00210-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation.
Collapse
Affiliation(s)
- D M Raffel
- Division of Nuclear Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109-0552, USA.
| | | |
Collapse
|
44
|
Dutka DP, Camici PG. The contribution of positron emission tomography to the study of ischemic heart failure. Prog Cardiovasc Dis 2001; 43:399-418. [PMID: 11251127 DOI: 10.1053/pcad.2001.20673] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cardiac imaging with positron emission tomography offers unrivaled sensitivity and specificity to probe cardiovascular physiology in health and disease. The use of positron emission tomography to noninvasively measure regional myocardial blood flow and assess myocardial viability in patients with ventricular dysfunction and coronary artery disease has contributed greatly to our understanding of the pathophysiology of ischemic heart failure. The advances and the need for further studies to establish both the natural history of such ventricular dysfunction and the role of coronary revascularization are discussed.
Collapse
Affiliation(s)
- D P Dutka
- MRC Clinical Sciences Centre, Imperial College School of Medicine, London, England
| | | |
Collapse
|
45
|
Langer O, Dollé F, Valette H, Halldin C, Vaufrey F, Fuseau C, Coulon C, Ottaviani M, Någren K, Bottlaender M, Maziére B, Crouzel C. Synthesis of high-specific-radioactivity 4- and 6-[18F]fluorometaraminol-PET tracers for the adrenergic nervous system of the heart. Bioorg Med Chem 2001; 9:677-94. [PMID: 11310603 DOI: 10.1016/s0968-0896(00)00286-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fluorine-18- (t(1/2) 109.8 min) and carbon-11 (t(1/2) 20.4 min)-labeled norepinephrine analogues have been found previously to be useful positron-emission-tomography (PET) radioligands to map adrenergic nerve terminals of the heart. Metaraminol ((1R,2S)-2-amino-1-(3-hydroxyphenyl)-1-propanol) is a metabolically stable structural analogue of norepinephrine and possesses high affinity towards the norepinephrine transporter and the vesicular monoamine transporter. This paper presents the radiosynthesis of new positron-emission-tomography halogeno analogues of metaraminol labeled with high specific radioactivity. Firstly, fluorine-18-labeled 4-fluorometaraminol (4-[18F]FMR or (1R,2S)-2-amino-1-(4-[18F]fluoro-3-hydroxyphenyl)-1-propanol) and its three other stereoisomers were prepared based on the following key steps: (a) condensation of the corresponding no-carrier-added labeled fluorobenzaldehyde with nitroethane, and (b) HPLC (C18 and chiral) resolution of the diastereomeric product mixture into the four individual enantiomers. Secondly, the corresponding 6-fluoro analogues, fluorine-18-labeled 6-fluorometaraminol (6-[18F]FMR or (1R,2S)-2-amino-1-(2-[18F]fluoro-5-hydroxyphenyl)-1-propanol) and its three other enantiomers, were prepared in an analogous way. Typically, 0.48-0.55 GBq of 4-[18F]FMR and 0.14-0.15 GBq of 6-[18F]FMR could be obtained after 120-160 min total synthesis time, with a specific radioactivity of 56-106 GBq/micromol. Furthermore, the synthesis of racemic 4-fluorometaraminol and 6-fluorometaraminol as reference compounds was performed. as well as independent chiral syntheses of the optically active (1R,2S) enantiomers. For the chiral syntheses, the key step was an electrophilic fluorination with acetyl hypofluorite of (1R,2S)-configurated organometallic derivatives of metaraminol. Tissue distribution studies in rats suggested that both 4-[18F]FMR and 6-[18F]FMR display similar affinity towards the presynaptic adrenergic nerve terminal in the heart. From a practical point of view, 4-[18F]FMR appeared to be the more attractive candidate for future PET investigations, due to higher radiochemical yields.
Collapse
Affiliation(s)
- O Langer
- Service Hospitalier Frédéric Joliot, Département de Recherche Médicale, CEA, Orsay, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Armario P, Hernández del Rey R, Almendros Ribas M. Papel del sistema nervioso simpático en la etiopatogenia de la hipertensión arterial. HIPERTENSION Y RIESGO VASCULAR 2001. [DOI: 10.1016/s1889-1837(01)71175-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
47
|
Li ST, Tack CJ, Fananapazir L, Goldstein DS. Myocardial perfusion and sympathetic innervation in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol 2000; 35:1867-73. [PMID: 10841237 DOI: 10.1016/s0735-1097(00)00626-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES This study assessed left ventricular myocardial perfusion and sympathetic innervation and function in hypertrophied and nonhypertrophied myocardial regions of patients with hypertrophic cardiomyopathy (HCM). BACKGROUND Patients with HCM often have clinical findings consistent with increased cardiac sympathetic outflow. Little is known about the status of sympathetic innervation specifically in hypertrophic regions. METHODS We conducted positron emission tomographic (PET) scanning using the perfusion imaging agent 13N-ammonia (13NH3) and the sympathoneuronal imaging agent 6-[18F]-fluorodopamine (18F-FDA) in 8 patients with HCM and 15 normal volunteers. Positron emission tomographic data corrected for attenuation and the partial volume effect were analyzed using the region-of-interest technique. RESULTS Myocardial 13NH3-derived radioactivity was similar in hypertrophied and nonhypertrophied regions of patients with HCM and in normal volunteers. At all time points, the 18F:13N ratio was lower in hypertrophied than in nonhypertrophied regions of HCM patients and in the septum of normal volunteers (p = 0.001). Trends in 18F-FDA-derived radioactivity over time were normal in both hypertrophied and nonhypertrophied myocardium. CONCLUSIONS The results are consistent with decreased neuronal uptake of catecholamines in hypertrophied but not in nonhypertrophied myocardium of patients with HCM. Other aspects of cardiac sympathoneural function seem normal. Decreased neuronal uptake could reflect local relative hypoinnervation, decreased numbers of neuronal uptake sites, or metabolic limitations on cell membrane transport. By enhancing norepinephrine delivery to adrenoceptors for a given amount of sympathetic nerve traffic, decreased neuronal uptake can explain major clinical features of HCM.
Collapse
Affiliation(s)
- S T Li
- Clinical Neurocardiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | | | | | |
Collapse
|
48
|
Langer O, Valette H, Dollé F, Halldin C, Loc'h C, Fuseau C, Coulon C, Ottaviani M, Bottlaender M, Mazière B, Crouzel C. High specific radioactivity (1R,2S)-4-[(18)F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart. Nucl Med Biol 2000; 27:233-8. [PMID: 10832079 DOI: 10.1016/s0969-8051(00)00082-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The radiolabeled catecholamine analogue (1R, 2S)-6-[(18)F]fluorometaraminol (6-[(18)F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[(18)F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[(18)F]fluorometaraminol (4-[(18)F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/micromol). In the present study, we demonstrate in rats that 4-[(18)F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[(18)F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[(18)F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[(18)F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[(18)F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[(18)F]FMR is a promising alternative to 6-[(18)F]FMR for myocardial neuronal mapping with PET in humans.
Collapse
Affiliation(s)
- O Langer
- Service Hospitalier Frédéric Joliot, Département de Recherche Médicale, CEA, Orsay, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Pike VW, Law MP, Osman S, Davenport RJ, Rimoldi O, Giardinà D, Camici PG. Selection, design and evaluation of new radioligands for PET studies of cardiac adrenoceptors. PHARMACEUTICA ACTA HELVETIAE 2000; 74:191-200. [PMID: 10812957 DOI: 10.1016/s0031-6865(99)00032-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Changes in the numbers of human cardiac adrenoceptors (ARs) are associated with various diseases, such as myocardial ischemia, congestive heart failure, cardiomyopathy and hypertension. There is a clear need for capability to assess human cardiac ARs directly in vivo. Positron emission tomography (PET) is an imaging technique that provides this possibility, if effective radioligands can be developed for the targeted ARs. Here, the status of myocardial AR radioligand development for PET is described. Currently, there exist effective radioligands for imaging beta-ARs in human myocardium. One of these, [11C](S)-CGP 12177, is applied extensively to clinical research with PET, sometimes with other tracers of other aspects of the noradrenalin system. Alternative radioligands are in development for beta-ARs, including beta 1-selective radioligands. A promising radioligand for imaging myocardial alpha 1-ARs, [11C]GB67, is now being evaluated in human PET experiments.
Collapse
Affiliation(s)
- V W Pike
- MRC Cyclotron Unit, Imperial College School of Medicine, Hammersmith Hospital, London, UK.
| | | | | | | | | | | | | |
Collapse
|
50
|
|