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Neumann J, Hofmann B, Dhein S, Gergs U. Role of Dopamine in the Heart in Health and Disease. Int J Mol Sci 2023; 24:ijms24055042. [PMID: 36902474 PMCID: PMC10003060 DOI: 10.3390/ijms24055042] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 02/25/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Dopamine has effects on the mammalian heart. These effects can include an increase in the force of contraction, and an elevation of the beating rate and the constriction of coronary arteries. Depending on the species studied, positive inotropic effects were strong, very modest, or absent, or even negative inotropic effects occurred. We can discern five dopamine receptors. In addition, the signal transduction by dopamine receptors and the regulation of the expression of cardiac dopamine receptors will be of interest to us, because this might be a tempting area of drug development. Dopamine acts in a species-dependent fashion on these cardiac dopamine receptors, but also on cardiac adrenergic receptors. We will discuss the utility of drugs that are currently available as tools to understand cardiac dopamine receptors. The molecule dopamine itself is present in the mammalian heart. Therefore, cardiac dopamine might act as an autocrine or paracrine compound in the mammalian heart. Dopamine itself might cause cardiac diseases. Moreover, the cardiac function of dopamine and the expression of dopamine receptors in the heart can be altered in diseases such as sepsis. Various drugs for cardiac and non-cardiac diseases are currently in the clinic that are, at least in part, agonists or antagonists at dopamine receptors. We define the research needs in order to understand dopamine receptors in the heart better. All in all, an update on the role of dopamine receptors in the human heart appears to be clinically relevant, and is thus presented here.
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Affiliation(s)
- Joachim Neumann
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
- Correspondence: ; Tel.: +49-345-557-1686; Fax: +49-345-557-1835
| | - Britt Hofmann
- Herzchirurgie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
| | - Stefan Dhein
- Medizinische Fakultät, Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, 04107 Leipzig, Germany
| | - Ulrich Gergs
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Martin-Luther-Universität Halle-Wittenberg, 06097 Halle, Germany
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Spiros A, Geerts H. Toward Predicting Impact of Common Genetic Variants on Schizophrenia Clinical Responses With Antipsychotics: A Quantitative System Pharmacology Study. Front Neurosci 2021; 15:738903. [PMID: 34658776 PMCID: PMC8511786 DOI: 10.3389/fnins.2021.738903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
CNS disorders are lagging behind other indications in implementing genotype-dependent treatment algorithms for personalized medicine. This report uses a biophysically realistic computer model of an associative and dorsal motor cortico-striatal-thalamo-cortical loop and a working memory cortical model to investigate the pharmacodynamic effects of COMTVal158Met rs4680, 5-HTTLPR rs 25531 s/L and D2DRTaq1A1 genotypes on the clinical response of 7 antipsychotics. The effect of the genotypes on dopamine and serotonin dynamics and the level of target exposure for the drugs was calibrated from PET displacement studies. The simulations suggest strong gene-gene pharmacodynamic interactions unique to each antipsychotic. For PANSS Total, the D2DRTaq1 allele has the biggest impact, followed by the 5-HTTLPR rs25531. The A2A2 genotype improved efficacy for all drugs, with a more complex outcome for the 5-HTTLPR rs25531 genotype. Maximal range in PANSS Total for all 27 individual combinations is 3 (aripiprazole) to 5 points (clozapine). The 5-HTTLPR L/L with aripiprazole and risperidone and the D2DRTaq1A2A2 allele with haloperidol, clozapine and quetiapine reduce the motor side-effects with opposite effects for the s/s genotype. The COMT genotype has a limited effect on antipsychotic effect and EPS. For cognition, the COMT MM 5-HTTLPR L/L genotype combination has the best performance for all antipsychotics, except clozapine. Maximal difference is 25% of the total dynamic range in a 2-back working memory task. Aripiprazole is the medication that is best suited for the largest number of genotype combinations (10) followed by Clozapine and risperidone (6), haloperidol and olanzapine (3) and quetiapine and paliperidone for one genotype. In principle, the platform could identify the best antipsychotic treatment balancing efficacy and side-effects for a specific individual genotype. Once the predictions of this platform are validated in a clinical setting the platform has potential to support rational personalized treatment guidance in clinical practice.
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Affiliation(s)
- Athan Spiros
- In Silico Biosciences, Berwyn, PA, United States
| | - Hugo Geerts
- In Silico Biosciences, Berwyn, PA, United States.,Certara QSP, Canterbury, United Kingdom
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3
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Bertoglio D, Verhaeghe J, Miranda A, Wyffels L, Stroobants S, Dominguez C, Munoz-Sanjuan I, Skinbjerg M, Liu L, Staelens S. Kinetic Modelling and Test-Retest Reproducibility for the Dopamine D 1R Radioligand [ 11C]SCH23390 in Healthy and Diseased Mice. Mol Imaging Biol 2020; 23:208-219. [PMID: 33179158 PMCID: PMC7910372 DOI: 10.1007/s11307-020-01561-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 01/25/2023]
Abstract
Purpose Our aim in this study was to compare different non-invasive pharmacokinetic models and assess test–retest reproducibility of the radioligand [11C]SCH23390 for the quantification of dopamine D1-like receptor (D1R) in both wild-type (WT) mice and heterozygous (HET) Q175DN mice as Huntington’s disease (HD) model. Procedures Adult WT (n = 9) and HET (n = 14) mice underwent a 90-min [11C]SCH23390 positron emission tomography (PET) scan followed by computed tomography (CT) to evaluate the pharmacokinetic modelling in healthy and diseased conditions. Additionally, 5 WT mice and 7 HET animals received a second [11C]SCH23390 PET scan for test–retest reproducibility. Parallel assessment of the simplified reference tissue model (SRTM), the multilinear reference tissue model (MRTM) and the Logan reference tissue model (Logan Ref) using the striatum as a receptor-rich region and the cerebellum as a receptor-free (reference) region was performed to define the most suitable method for regional- and voxel-based quantification of the binding potential (BPND). Finally, standardised uptake value ratio (SUVR-1) was assessed as a potential simplified measurement. Results For all models, we measured a significant decline in dopamine D1R density (e.g. SRTM = − 38.5 ± 5.0 %, p < 0.0001) in HET mice compared to WT littermates. Shortening the 90-min scan duration resulted in large underestimation of striatal BPND in both WT mice (SRTM 60 min: − 17.7 ± 2.8 %, p = 0.0078) and diseased HET (SRTM 60 min: − 13.1 ± 4.1 %, p = 0.0001). Striatal BPND measurements were very reproducible with an average test–retest variability below 5 % when using both MRTM and SRTM. Parametric BPND maps generated with SRTM were highly reliable, showing nearly perfect agreement to the regional analysis (r2 = 0.99, p < 0.0001). Finally, SRTM provided the most accurate estimate for relative tracer delivery R1 with both regional- and voxel-based analyses. SUVR-1 at different time intervals were not sufficiently reliable when compared to BPND (r2 < 0.66). Conclusions Ninety-minute acquisition and the use of SRTM for pharmacokinetic modelling is recommended. [11C]SCH23390 PET imaging demonstrates optimal characteristics for the study of dopamine D1R density in models of psychiatric and neurological disorders as exemplified in the Q175DN mouse model of HD. Supplementary Information The online version contains supplementary material available at 10.1007/s11307-020-01561-1.
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Affiliation(s)
- Daniele Bertoglio
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Alan Miranda
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium
| | - Leonie Wyffels
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | - Sigrid Stroobants
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.,Department of Nuclear Medicine, Antwerp University Hospital, Edegem, Belgium
| | | | | | | | - Longbin Liu
- CHDI Management/CHDI Foundation, Los Angeles, CA, USA
| | - Steven Staelens
- Molecular Imaging Center Antwerp (MICA), University of Antwerp, Wilrijk, Belgium.
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Burns JA, Kroll DS, Feldman DE, Kure Liu C, Manza P, Wiers CE, Volkow ND, Wang GJ. Molecular Imaging of Opioid and Dopamine Systems: Insights Into the Pharmacogenetics of Opioid Use Disorders. Front Psychiatry 2019; 10:626. [PMID: 31620026 PMCID: PMC6759955 DOI: 10.3389/fpsyt.2019.00626] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 08/05/2019] [Indexed: 12/21/2022] Open
Abstract
Opioid use in the United States has steadily risen since the 1990s, along with staggering increases in addiction and overdose fatalities. With this surge in prescription and illicit opioid abuse, it is paramount to understand the genetic risk factors and neuropsychological effects of opioid use disorder (OUD). Polymorphisms disrupting the opioid and dopamine systems have been associated with increased risk for developing substance use disorders. Molecular imaging studies have revealed how these polymorphisms impact the brain and contribute to cognitive and behavioral differences across individuals. Here, we review the current molecular imaging literature to assess how genetic variations in the opioid and dopamine systems affect function in the brain's reward, cognition, and stress pathways, potentially resulting in vulnerabilities to OUD. Continued research of the functional consequences of genetic variants and corresponding alterations in neural mechanisms will inform prevention and treatment of OUD.
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Affiliation(s)
- Jamie A Burns
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Danielle S Kroll
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Dana E Feldman
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | | | - Peter Manza
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Corinde E Wiers
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - Nora D Volkow
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States.,National Institute on Drug Abuse, Bethesda, MD, United States
| | - Gene-Jack Wang
- National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
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5
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Nutt D, Robbins T, Hayes A. THuNDRous news for human dopamine researchers: A selective dopamine D1 receptor antagonist will soon be available for clinical research. J Psychopharmacol 2018; 32:1153-1154. [PMID: 30354927 DOI: 10.1177/0269881118799380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
| | | | - Ann Hayes
- 3 The Ann Hayes Consultancy, Buntingford, UK
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6
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Striatal dopamine D1-type receptor availability: no difference from control but association with cortical thickness in methamphetamine users. Mol Psychiatry 2018; 23:1320-1327. [PMID: 28894300 PMCID: PMC5847392 DOI: 10.1038/mp.2017.172] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 06/01/2017] [Accepted: 06/07/2017] [Indexed: 01/17/2023]
Abstract
Chronic methamphetamine use poses potentially devastating consequences for directly affected individuals and for society. Lower dopamine D2-type receptor availability has been observed in striata of methamphetamine users as compared with controls, but an analogous comparison of D1-type receptors has been conducted only on post-mortem material, with no differences in methamphetamine users from controls in the caudate nucleus and putamen and higher D1-receptor density in the nucleus accumbens. Released from neurons when methamphetamine is self-administered, dopamine binds to both D1- and D2-type receptors in the striatum, with downstream effects on cortical activity. Thus, both receptor subtypes may contribute to methamphetamine-induced alterations in cortical morphology and behavior. In this study, 21 methamphetamine-dependent subjects and 23 healthy controls participated in positron emission tomography and structural magnetic resonance imaging for assessment of striatal D1- and D2-type receptor availability and cortical gray-matter thickness, respectively. Although D2-type receptor availability (BPnd) was lower in the methamphetamine group, as shown previously, the groups did not differ in D1-type BPnd. In the methamphetamine group, mean cortical gray-matter thickness was negatively associated with cumulative methamphetamine use and craving for the drug. Striatal D1-type but not D2-type BPnd was negatively associated with global mean cortical gray-matter thickness in the methamphetamine group, but no association was found between gray-matter thickness and BPnd for either dopamine receptor subtype in the control group. These results suggest a role of striatal D1-type receptors in cortical adaptation to chronic methamphetamine use.
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Abstract
The dopamine (DA) system is considered to be centrally involved in the pathophysiology of several major psychiatric disorders. Using positron emission tomography (PET), aberrations in dopamine D2/D3-receptors (D2-R) levels and uptake of the DA precursor FDOPA have been shown for schizophrenia, substance abuse and depression. Radioligands for the dopamine D1-receptor (D1-R) have been available for more than three decades, however this receptor subtype has received much less attention in psychiatry research. Here, studies investigating D1-R in psychiatric patients in comparison to healthy control subjects are summarized. Although small sample sizes, medication effects and heterogeneous methods of quantification limit the conclusions that can be drawn, the data is suggestive of higher levels of cortical D1-R in drug naïve patients with psychosis, and lower D1-R in patients with affective disorders. Data sharing and reanalysis using harmonized methodology are important next steps towards clarifying the role of D1-R in these disorders.
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Affiliation(s)
- Simon Cervenka
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, SE-171 76 Stockholm, Sweden.
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8
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Dopamine D1 Binding Potential Predicts Fusiform BOLD Activity during Face-Recognition Performance. J Neurosci 2016; 35:14702-7. [PMID: 26538642 DOI: 10.1523/jneurosci.1298-15.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The importance of face memory in humans and primates is well established, but little is known about the neurotransmitter systems involved in face recognition. We tested the hypothesis that face recognition is linked to dopamine (DA) activity in fusiform gyrus (FFG). DA availability was assessed by measuring D1 binding potential (BP) during rest using PET. We further assessed blood-oxygen-level-dependent (BOLD) signal change while subjects performed a face-recognition task during fMRI scanning. There was a strong association between D1 BP and BOLD activity in FFG, whereas D1 BP in striatal and other extrastriatal regions were unrelated to neural activity in FFG. These results suggest that D1 BP locally modulates FFG function during face recognition. Observed relationships among D1 BP, BOLD activity, and face-recognition performance further suggest that D1 receptors place constraints on the responsiveness of FFG neurons. SIGNIFICANCE STATEMENT The importance of face memory in humans and primates is well established, but little is known about the neurotransmitter systems involved in face recognition. Our work shows a role for a specific neurotransmitter system in face memory.
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Striatal D1- and D2-type dopamine receptors are linked to motor response inhibition in human subjects. J Neurosci 2015; 35:5990-7. [PMID: 25878272 DOI: 10.1523/jneurosci.4850-14.2015] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Motor response inhibition is mediated by neural circuits involving dopaminergic transmission; however, the relative contributions of dopaminergic signaling via D1- and D2-type receptors are unclear. Although evidence supports dissociable contributions of D1- and D2-type receptors to response inhibition in rats and associations of D2-type receptors to response inhibition in humans, the relationship between D1-type receptors and response inhibition has not been evaluated in humans. Here, we tested whether individual differences in striatal D1- and D2-type receptors are related to response inhibition in human subjects, possibly in opposing ways. Thirty-one volunteers participated. Response inhibition was indexed by stop-signal reaction time on the stop-signal task and commission errors on the continuous performance task, and tested for association with striatal D1- and D2-type receptor availability [binding potential referred to nondisplaceable uptake (BPND)], measured using positron emission tomography with [(11)C]NNC-112 and [(18)F]fallypride, respectively. Stop-signal reaction time was negatively correlated with D1- and D2-type BPND in whole striatum, with significant relationships involving the dorsal striatum, but not the ventral striatum, and no significant correlations involving the continuous performance task. The results indicate that dopamine D1- and D2-type receptors are associated with response inhibition, and identify the dorsal striatum as an important locus of dopaminergic control in stopping. Moreover, the similar contribution of both receptor subtypes suggests the importance of a relative balance between phasic and tonic dopaminergic activity subserved by D1- and D2-type receptors, respectively, in support of response inhibition. The results also suggest that the stop-signal task and the continuous performance task use different neurochemical mechanisms subserving motor response inhibition.
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Pansuriya PB, Maguire GEM, Friedrich HB. Synthesis and structural elucidation of a novel polymorph of alcaftadine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 142:311-319. [PMID: 25706601 DOI: 10.1016/j.saa.2015.01.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 01/16/2015] [Accepted: 01/29/2015] [Indexed: 06/04/2023]
Abstract
In this study, we have synthesized and elucidated the structure of the H1 histamine antagonist, 2-(1-methylpiperidin-4-ylidene)-4,7-diazatricyclo[8.4.0.0((3,7))]tetradeca-1(14),3,5,10,12-pentaene-6-carbaldehyde in the solution and solid-state. We have also studied the thermal dilapidation of the compound. Solution structure analysis was achieved by employing NMR spectroscopy including 2D experiments NOESY, HSQC and HMBC, while solid state investigations were undertaken using SXRD, PXRD, TGA, DSC, and IR spectroscopy. For the first time the single crystal structure of alcaftadine has now been solved. Crystallographic data are as follows: monoclinic, Cc, a=11.5694(6)Å, b=14.5864(6)Å, c=10.2688(4)Å, α=90°, β=111.793(3)°, γ=90°, V=1609.07(13)Å(3), Z=4. The Hirshfeld surface analyses also have been performed using the crystal structure.
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Affiliation(s)
- Pramod B Pansuriya
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Glenn E M Maguire
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa
| | - Holger B Friedrich
- School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa.
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Prante O, Maschauer S, Banerjee A. Radioligands for the dopamine receptor subtypes. J Labelled Comp Radiopharm 2014; 56:130-48. [PMID: 24285319 DOI: 10.1002/jlcr.3000] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 10/11/2012] [Accepted: 11/06/2012] [Indexed: 12/29/2022]
Abstract
The actions of the predominant neurotransmitter in the brain, dopamine, are mediated by the postsynaptic dopamine receptors. The five dopamine receptor subtypes and their regulation have been associated with a large variety of psychiatric diseases. Therefore, positron emission tomography (PET) imaging studies using suitable and selective (18) F-labeled and (11) C-labeled dopamine receptor radioligands could provide valuable knowledge on the impact of receptor density on the pathogenesis and evolvement of neuropsychiatric and neurological diseases. This special issue subchapter provides a summary of the most important (18) F-labeled and (11) C-labeled radioligands for PET imaging of the dopamine receptor subtypes, their radiochemistry, and characteristics from in vitro and in vivo applications, considering not only the already established PET ligands but also the recently published preclinical work.
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Affiliation(s)
- Olaf Prante
- Laboratory of Molecular Imaging and Radiochemistry, Friedrich-Alexander University, Schwabachanlage 6, D-91054, Erlangen, Germany
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Karimi M, Moerlein SM, Videen TO, Su Y, Flores HP, Perlmutter JS. Striatal dopamine D1-like receptor binding is unchanged in primary focal dystonia. Mov Disord 2013; 28:2002-6. [PMID: 24151192 PMCID: PMC4086787 DOI: 10.1002/mds.25720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/19/2013] [Accepted: 09/23/2013] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Multiple studies have demonstrated decreases in striatal D2-like (D2, D3) radioligand binding in primary focal dystonias. Although most investigations have focused on D2-specific receptors (D2R), a recent study suggests that the decreased D2-like binding may be due to a D3-specific (D3R) abnormality. However, only limited data exist on the role of D1-specific receptors (D1R) and the D1R-mediated pathways within basal ganglia in dystonia. Metabolic positron emission tomography (PET) data in primary generalized dystonia suggest resting state over activity in the D1R-mediated direct pathway, leading to excessive disinhibition of motor cortical areas. This work investigated whether striatal D1-like receptors are affected in primary focal dystonias. METHODS Striatal-specific (caudate and putamen) binding of the D1-like radioligand [(11)C]NNC 112 was measured using PET in 19 patients with primary focal dystonia (cranial, cervical, or arm) and 18 controls. RESULTS No statistically significant difference was detected in striatal D1-like binding between the two groups. The study had 91% power to detect a 20% difference, indicating that false-negative results were unlikely. CONCLUSIONS Because [(11)C]NNC 112 has high affinity for D1-like receptors, very low affinity for D2-like receptors, and minimal sensitivity to endogenous dopamine levels, we conclude that D1-like receptor binding is not impaired in these primary focal dystonias.
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Affiliation(s)
- Morvarid Karimi
- Department of Neurology, Washington University School of Medicine, Saint Louis, Missouri, USA
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Design, synthesis, and pharmacological evaluation of novel tetrahydroprotoberberine derivatives: Selective inhibitors of dopamine D1 receptor. Bioorg Med Chem 2012; 20:4862-71. [DOI: 10.1016/j.bmc.2012.05.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Revised: 05/23/2012] [Accepted: 05/24/2012] [Indexed: 01/11/2023]
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Abstract
The results of imaging studies have played an important role in the formulation of hypotheses regarding the etiology of psychosis and schizophrenia, as well as in our understanding of the mechanisms of action of antipsychotics. Since this volume is primarily directed to molecular aspects of psychosis and antipsychotics, only the results of molecular imaging techniques addressing these topics will be discussed here.One of the most consistent findings of molecular imaging studies in schizophrenia is an increased uptake of DOPA in the striatum, which may be interpreted as an increased synthesis of L-DOPA. Also, several studies reported an increased release of dopamine induced by amphetamine in schizophrenia patients. These findings played an important role in reformulating the dopamine hypothesis of schizophrenia. To study the roles of the neurotransmitters γ-aminobutyric acid (GABA) and glutamate in schizophrenia, SPECT as well as MR spectroscopy have been used. The results of preliminary SPECT studies are consistent with the hypothesis of NMDA receptor dysfunction in schizophrenia. Regarding the GABA deficit hypothesis of schizophrenia, imaging results are inconsistent. No changes in serotonin transporters were demonstrated in imaging studies in schizophrenia, but studies of several serotonin receptors showed conflicting results. The lack of selective radiotracers for muscarinic receptors may have hampered examination of this system in schizophrenia as well as its role in the induction of side effects of antipsychotics. Interestingly, preliminary molecular imaging studies on the cannabinoid-1 receptor and on neuroinflammatory processes in schizophrenia have recently been published. Finally, a substantial number of PET/SPECT studies have examined the occupancy of receptors by antipsychotics and an increasing number of studies is now focusing on the effects of these drugs using techniques like spectroscopy and pharmacological MRI.
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Ariza M, Díaz A, Suau R, Valpuesta M. Synthesis of New Dopamine D1 Antagonist SCH 23390 Analogues by the Stereoselective Stevens Rearrangement. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100991] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Imaging cortical dopamine D1 receptors using [11C]NNC112 and ketanserin blockade of the 5-HT 2A receptors. J Cereb Blood Flow Metab 2010; 30:985-93. [PMID: 20029452 PMCID: PMC2949183 DOI: 10.1038/jcbfm.2009.269] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
[(11)C]NNC112 (8-chloro-7-hydroxy-3-methyl-5-(7-benzofuranyl)-2,3,4,5-tetrahydro-IH-3-benzazepine), a selective positron-emission tomography (PET) ligand for the D(1) receptor (R) over the 5-HT(2A) R in vitro, has shown lower selectivity in vivo, hampering measurement of D(1) R in the cortex. [(11)C]NNC112 PET and intravenous (i.v) ketanserin challenge were used to (1) confirm the previous findings of [(11)C]NNC112 in vivo D(1) R selectivity, and (2) develop a feasible methodology for imaging cortical D(1) R without contamination by 5-HT(2A) R. Seven healthy volunteers underwent [(11)C]NNC112 PET scans at baseline and after a 5-HT(2A) R-blocking dose of ketanserin (0.15 mg/kg, i.v.). Percent BP(ND) change between the post-ketanserin and baseline scans was calculated. Irrespective of the quantification method used, ketanserin pretreatment led to significant decrease of BP(ND) in the cortical (approximately 30%) and limbic regions (approximately 20%) but not in the striatum, which contains a much lower amount of 5-HT(2A) R. Therefore, ketanserin allows D(1) R signal to be detected by [(11)C]NNC112 PET without significant 5-HT(2A) R contamination. These data confirm the presence of a significant 5-HT(2A) R contribution to cortical [(11)C]NNC112 signal, and call for caution in the interpretation of published [(11)C]NNC112 PET findings on cortical D(1) R in humans. In the absence of more selective ligands, [(11)C]NNC112 PET with ketanserin can be used for cortical D(1) R imaging in vivo.
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Gozzi A, Crestan V, Turrini G, Clemens M, Bifone A. Antagonism at serotonin 5-HT(2A) receptors modulates functional activity of frontohippocampal circuit. Psychopharmacology (Berl) 2010; 209:37-50. [PMID: 20111859 DOI: 10.1007/s00213-009-1772-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Accepted: 12/20/2009] [Indexed: 12/22/2022]
Abstract
RATIONALE Several second-generation antipsychotics are characterised by a significant antagonistic effect at serotonin 5-HT(2A) receptors (5-HT(2A)R), a feature that has been associated with lower incidence of extra-pyramidal symptoms and a putative amelioration of positive and negative symptoms experienced by schizophrenic patients. However, the neurofunctional substrate of 5-HT(2A) antagonism and its exact contribution to the complex pharmacological profile of these drugs remain to be elucidated. OBJECTIVES Here, we used pharmacological magnetic resonance imaging to map the modulatory effects of the selective 5-HT(2A)R antagonist Ml00907 on the spatiotemporal patterns of brain activity elicited by acute phencyclidine (PCP) challenge in the rat. PCP is a non-competitive NMDA receptor antagonist that induces dysregulation of corticolimbic glutamatergic neurotransmission and produces cognitive impairment and psychotic-like symptoms reminiscent of those observed in schizophrenia. RESULTS Pre-administration of M100907 produced focal and region-dependent attenuation of PCP-induced response in frontoseptohippocampal areas. As early studies highlighted a permissive role of 5-HT(2A)R on frontal dopamine release, the role of post-synaptic dopamine D(1) receptors on PCP-induced response was examined by using the potent antagonist SCH23390. Interestingly, SCH23390 did not affect PCP's response in any of the regions examined. This finding rules out a significant contribution of dopamine in the functional changes mapped and, indirectly, the inhibitory effect of M100907, in favour of a glutamatergic origin. CONCLUSIONS Our data expand recent evidence suggesting a key role of 5-HT(2A)R in modulating glutamate-mediated cognitive performance in the prefrontal cortex and highlight the whole frontoseptohippocampal circuit as a key functional substrate of 5-HT(2A)R antagonism in normal and disease states.
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Affiliation(s)
- Alessandro Gozzi
- Biology, Neurosciences CEDD, GlaxoSmithKline Medicines Research Centre, Verona, Italy
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Sasikumar T, Burnett DA, Greenlee WJ, Smith M, Fawzi A, Zhang H, Lachowicz JE. Remote functionalization of SCH 39166: Discovery of potent and selective benzazepine dopamine D1 receptor antagonists. Bioorg Med Chem Lett 2010; 20:832-5. [DOI: 10.1016/j.bmcl.2009.12.094] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/22/2009] [Accepted: 12/24/2009] [Indexed: 11/25/2022]
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Dopamine type-1 receptor binding in major depressive disorder assessed using positron emission tomography and [11C]NNC-112. Neuropsychopharmacology 2009; 34:1277-87. [PMID: 18946469 PMCID: PMC2656589 DOI: 10.1038/npp.2008.194] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The dopamine type-1 receptor has been implicated in major depressive disorder (MDD) by clinical and preclinical evidence from neuroimaging, post mortem, and behavioral studies. To date, however, selective in vivo assessment of D(1) receptors has been limited to the striatum in MDD samples manifesting anger attacks. We employed the PET radioligand, [(11)C]NNC-112, to selectively assess D(1) receptor binding in extrastriatal and striatal regions in a more generalized sample of MDD subjects. The [(11)C]NNC-112 nondisplaceable binding potential (BP(ND)) was assessed using PET in 18 unmedicated, currently depressed subjects with MDD and 19 healthy controls, and compared between groups using MRI-based region-of-interest analysis. The mean D(1) receptor BP(ND) was reduced (14%) in the left middle caudate of the MDD group relative to control group (p<0.05). Among the MDD subjects D(1) receptor BP(ND) in this region correlated negatively with illness duration (r=-0.53; p=0.02), and the left-to-right BP(ND) ratio correlated inversely with anhedonia ratings (r=-0.65, p=0.0040). The D(1) receptor BP(ND) was strongly lateralized in striatal regions (p<0.002 for main effects of hemisphere in accumbens area, putamen, and caudate). In post hoc analyses, a group-by-hemisphere-by-gender interaction was detected in the dorsal putamen, which was accounted for by a loss of the normal asymmetry in depressed women (F=7.33, p=0.01). These data extended a previous finding of decreased striatal D(1) receptor binding in an MDD sample manifesting anger attacks to a sample selected more generally according to MDD criteria. Our data also more specifically localized this abnormality in MDD to the left middle caudate, which is the target of afferent neural projections from the orbitofrontal and anterior cingulate cortices where neuropathological changes have been reported in MDD. Finally, D(1) receptor binding was asymmetrical across hemispheres in healthy humans, compatible with evidence that dopaminergic function in the striatum is lateralized during reward processing, voluntary movement, and self-stimulation behavior.
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Enzensperger C, Görnemann T, Pertz HH, Lehmann J. Dopamine/serotonin receptor ligands. Part 17: A cross-target SAR approach: Affinities of azecine-styled ligands for 5-HT2A versus D1 and D2 receptors. Bioorg Med Chem Lett 2008; 18:3809-13. [DOI: 10.1016/j.bmcl.2008.04.081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 04/28/2008] [Accepted: 04/29/2008] [Indexed: 11/16/2022]
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Klimas MT. Central & Peripheral Nervous System: Overview D1selective and mixed D1/D2dopaminergic compounds: Structural diversity and recent advances. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.4.12.1493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Slifstein M, Kegeles LS, Gonzales R, Frankle WG, Xu X, Laruelle M, Abi-Dargham A. [11C]NNC 112 selectivity for dopamine D1 and serotonin 5-HT(2A) receptors: a PET study in healthy human subjects. J Cereb Blood Flow Metab 2007; 27:1733-41. [PMID: 17311076 DOI: 10.1038/sj.jcbfm.9600468] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The dopamine D(1) receptor antagonist radioligand [(11)C]NNC 112 has previously been reported to have 100-fold selectivity for the D(1) receptor compared with the serotonin 5-HT(2A) receptor. In this study, we tested the selectivity by scanning seven healthy human research volunteers with [(11)C]NNC 112 before and after 2 mg of the antipsychotic drug risperidone, a dose that putatively blocks all 5-HT(2A) receptors with negligible effect on D(1) receptors. We found that specific binding in cortical regions was reduced by 20% to 30%, whereas the striatum showed no change. Based on the known relative densities of these receptors in humans, our results suggest 5- to 10-fold selectivity of [(11)C]NNC 112 for D(1) versus 5-HT(2A) as opposed to 100-fold selectivity. These results suggest caution in interpreting data from studies using this tracer to measure cortical D(1) receptors as well as the need for more selective radioligands to assess cortical D(1) receptors.
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Affiliation(s)
- Mark Slifstein
- Department of Psychiatry, Columbia University, New York, New York, USA.
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23
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Smith DF, Jakobsen S. Stereoselective neuroimaging in vivo. Eur Neuropsychopharmacol 2007; 17:507-22. [PMID: 17368004 DOI: 10.1016/j.euroneuro.2007.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 01/17/2007] [Accepted: 02/06/2007] [Indexed: 01/08/2023]
Abstract
Stereoselectivity is a basic property of many neuronal processes due to the spatial features of molecules involved in neurotransmission. Today, neuroimaging procedures are available for studying stereoselectivity in the living brain. Mirror-image radiotracers are the molecular tools that are used, together with single photon emission tomography (SPECT) and positron emission tomography (PET), for studying stereoselective neuronal mechanisms. This review presents the findings obtained in those studies of cholinergic, noradrenergic, dopaminergic, serotonergic, glutamatergic, opioid, cannabinoid, and second messenger neurotransmission.
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Affiliation(s)
- Donald F Smith
- Center for Psychiatric Research, Psychiatric Hospital of Aarhus University, 8240 Risskov, Denmark.
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Ekelund J, Slifstein M, Narendran R, Guillin O, Belani H, Guo NN, Hwang Y, Hwang DR, Abi-Dargham A, Laruelle M. In vivo DA D(1) receptor selectivity of NNC 112 and SCH 23390. Mol Imaging Biol 2007; 9:117-25. [PMID: 17473957 DOI: 10.1007/s11307-007-0077-4] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE [(11)C]NNC 112 and [(11)C]SCH 23390 are selective positron emission tomography (PET) tracers for visualizing dopamine D(1) receptors. It is known that both have some affinity for serotonin 2A receptors, but previous studies have suggested this is negligible compared to D(1) affinity. We sought to verify this property in vivo. PROCEDURES Two baboons were scanned to measure the selectivity of both tracers with a displacement paradigm. Four baboons were scanned to directly assess [(11)C] NNC 112 affinity for both receptors. RESULTS In vivo, D(1) to 5-HT(2A) selectivity is six to fourteenfold, not 100-fold as previously reported by other investigators. CONCLUSION We conclude that about 1/4 of the cortical signal of both [(11)C]NNC 112 and [(11)C]SCH 23390 is due to binding to 5-HT(2A) receptors. If confirmed in humans, this suggests caution should be exercised when drawing conclusions from studies using either tracer. These results also indicate the need for more selective tracers for the D(1) receptor.
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Affiliation(s)
- Jesper Ekelund
- Department of Psychiatry, Columbia University, New York, NY, USA
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25
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Foged C, Hansen LB, Halldin C. 14C-labelling of NNC 756, a new dopamine D1 antagonist. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580330811] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Wu WL, Burnett DA, Spring R, Greenlee WJ, Smith M, Favreau L, Fawzi A, Zhang H, Lachowicz JE. Dopamine D1/D5 receptor antagonists with improved pharmacokinetics: design, synthesis, and biological evaluation of phenol bioisosteric analogues of benzazepine D1/D5 antagonists. J Med Chem 2005; 48:680-93. [PMID: 15689153 DOI: 10.1021/jm030614p] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Benzazepines 1 and 2 (SCH 23390 and SCH 39166, respectively) are two classical benzazepine D1/D5 antagonists, with Ki values 1.4 and 1.2 nM, respectively. Compound 2 has been in human clinical trials for a variety of diseases, including schizophrenia, cocaine addition, and obesity. Both 1 and 2 displayed low plasma levels and poor oral bioavailability, due to rapid first-pass metabolism of the phenol moieties. Several heterocyclic systems containing an N-H hydrogen bond donor were synthesized and evaluated as phenol isosteres. The preference orientation of the hydrogen bond was established by comparison of analogues containing different NH vectors. Replacement of the phenol group of 2 with an indole ring generated the first potent D1/D5 antagonist 11b. Further optimization led to the synthesis of very potent benzimidazolones 19, 20 and benzothiazolone analogues 28, 29. These compounds have excellent selectivity over D2-D4 receptors, alpha2a receptor, and the 5-HT transporter. Compared to 2, these heterocyclic phenol isosteres showed much better pharmacokinetic profiles as demonstrated by rat plasma levels. In sharp contrast, similar phenolic replacements in 1 decreased the binding affinity dramatically, presumably due to a conformational change of the pendant phenyl group. However, one indazole compound 33 was identified as a potent D1/D5 ligand in this series.
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Affiliation(s)
- Wen-Lian Wu
- Schering-Plough Research Institute, 2015 Galloping Hill Road, Kenilworth, New Jersey 07033, USA.
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Nair SG, Gudelsky GA. 3,4-Methylenedioxymethamphetamine (MDMA) enhances the release of acetylcholine by 5-HT4 and D1 receptor mechanisms in the rat prefrontal cortex. Synapse 2005; 58:229-35. [PMID: 16206181 DOI: 10.1002/syn.20202] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
3,4-Methylenedioxymethamphetamine (MDMA), an amphetamine analog, has been shown recently to increase the release of acetylcholine (ACh) in the prefrontal cortex (PFC). The present study further characterizes the stimulatory effect of MDMA on cortical ACh release and examines the role of serotonin (5-HT) and dopamine (DA) receptors in this response. The extracellular concentration of ACh was increased dose-dependently and similarly by the (+) and (-) enantiomers of MDMA (5 and 20 mg/kg, i.p.). The systemic administration of the 5-HT(4) antagonist SDZ 205,557 (1 mg/kg, i.p.), but not the 5-HT(2A/2B/2C) antagonist LY-53,857 (3 mg/kg, i.p.), significantly decreased cortical ACh release induced by MDMA. The MDMA-induced increase in the extracellular concentration of ACh also was significantly blunted in rats treated with the D(1) receptor antagonist SCH 23390 (0.5 mg/kg, i.p.). The extent to which the coadministration of SDZ 205,557 and SCH 23390 suppressed the MDMA-induced release of ACh in the PFC was no greater than that produced by either antagonist alone. These results suggest that the 5-HT(4) and D(1) receptor subtypes contribute to the mechanism by which MDMA increases ACh release in the PFC.
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Affiliation(s)
- Sunila G Nair
- College of Pharmacy, University of Cincinnati, OH 45267, USA
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28
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Rosa-Neto P, Doudet DJ, Cumming P. Gradients of dopamine D1- and D2/3-binding sites in the basal ganglia of pig and monkey measured by PET. Neuroimage 2004; 22:1076-83. [PMID: 15219579 DOI: 10.1016/j.neuroimage.2004.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Revised: 03/02/2004] [Accepted: 03/03/2004] [Indexed: 11/19/2022] Open
Abstract
The distributions of dopamine D1 and D2/3 binding sites in living brain have not been compared directly using positron emission tomography (PET). To map these binding sites, we first optimized methods for the assay of dopamine receptors in brain of Göttingen miniature pigs. The binding potentials (pB) of [11C]NNC 112 for dopamine D1 receptors and [11C]raclopride for dopamine D2/3 receptors were calculated in pig striatum volumes of interest using metabolite corrected arterial inputs or using cerebellum as a non-binding reference region. Depending upon the method for quantitation, the pB for [11C]NNC 112 was 1.2-5.1 in pig striatum, whereas the pB for [11C]raclopride was 1.0-1.8. We used the reference tissue method of Logan to calculate pB maps for the two tracers. The maps were co-registered to the common stereotaxic space for the pig brain and normalized to a global mean for pB in striatum; t-maps showed that dopamine D1 binding was relatively more abundant in the ventral-anterior striatum of the pig, while dopamine D2/3 binding was greater in the dorsal striatum. Similar comparisons were made for the pBs of [11C]Sch 23390 for dopamine D1 receptors and for [11C]raclopride in the brain of six rhesus monkeys. The magnitudes of pB for both binding sites in monkey brain were close to those in the pig. Consistent with the pig results, there were distinct gradients in the distributions of the two binding sites in monkey brain: D1 binding predominated in the ventral striatum, whereas D2/3 binding was relatively greater in the dorsal-posterior striatum. Gradients of dopamine receptor concentration within the striatum may be a general phenomenon of mammalian brain.
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Affiliation(s)
- Pedro Rosa-Neto
- PET Centre, Aarhus University Hospitals, and Centre of Functionally Integrative Neuroscience (CFIN), Aarhus University, Aarhus, Denmark.
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Laruelle M, Kegeles LS, Abi-Dargham A. Glutamate, dopamine, and schizophrenia: from pathophysiology to treatment. Ann N Y Acad Sci 2004; 1003:138-58. [PMID: 14684442 DOI: 10.1196/annals.1300.063] [Citation(s) in RCA: 340] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The fundamental pathological process(es) associated with schizophrenia remain(s) uncertain, but multiple lines of evidence suggest that this condition is associated with (1) excessive stimulation of striatal dopamine (DA) D2 receptors, (2) deficient stimulation of prefrontal DA D1 receptors and, (3) alterations in prefrontal connectivity involving glutamate (GLU) transmission at N-methyl-d-aspartate (NMDA) receptors. This chapter first briefly discusses the current knowledge status for these abnormalities, with emphasis on results derived from clinical molecular imaging studies. The evidence for hyperstimulation of striatal D2 receptors rests on strong pharmacological evidence and has recently received support from brain imaging studies. The hypothesis of deficient prefrontal cortex (PFC) D1 receptor stimulation is almost entirely derived from preclinical studies. Preliminary imaging data compatible with this hypothesis have recently emerged. The NMDA hypofunction hypothesis originates mainly from indirect pharmacological data. The interactions between DA and GLU systems relevant to schizophrenia are then reviewed. Animal and imaging data supporting the general model that the putative DA imbalance in schizophrenia (striatal excess and cortical deficiency) might be secondary to NMDA hypofunction in the PFC and its connections are presented. Equally important are the potential consequences of this DA imbalance for NMDA function in the striatum and the cortex, which are subsequently discussed. In conclusion, it is proposed that schizophrenia is associated with strongly interconnected abnormalities of GLU and DA transmission: NMDA hypofunction in the PFC and its connections might generate a pattern of dysregulation of DA systems that, in turn, further weakens NMDA-mediated connectivity and plasticity.
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Affiliation(s)
- Marc Laruelle
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
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Abi-Dargham A, Moore H. Prefrontal DA transmission at D1 receptors and the pathology of schizophrenia. Neuroscientist 2003; 9:404-16. [PMID: 14580124 DOI: 10.1177/1073858403252674] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The current view on the dopamine (DA) hypothesis of schizophrenia postulates a cortical/subcortical imbalance: subcortical mesolimbic DA projections might be hyperactive, resulting in hyperstimulation of D2 receptors and positive symptoms, whereas mesocortical DA projections to the prefrontal cortex might be hypoactive, resulting in hypostimulation of D1 receptors, negative symptoms, and cognitive impairment. Although the subcortical abnormalities are relatively well established now, the evidence for cortical hypodopaminergia is just emerging. This article will review current evidence for prefrontal hypodopaminergia in schizophrenia, with special emphasis on positron emission tomography (PET) studies measuring cortical D1 receptors in schizophrenia. The presentation of the clinical data will be introduced by a brief overview of the function of prefrontal DA systems, both at the cellular and cognitive level. The impact of antipsychotic drugs on prefrontal DA function will also be reviewed. We will conclude with the formulation of several models of altered prefrontal DA transmission at D1 receptors in schizophrenia.
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Affiliation(s)
- Anissa Abi-Dargham
- Department of Psychiatry, Columbia University College of Physicians and Surgeons and New York State Psychiatric Institute, New York, NY 10032, USA.
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31
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32
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Suvire F, Cabedo N, Chagraoui A, Zamora M, Cortes D, Enriz R. Molecular recognition and binding mechanism of N-alkyl-benzyltetrahydroisoquinolines to the D1 dopamine receptor. A computational approach. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/j.theochem.2003.08.070] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Guo N, Hwang DR, Lo ES, Huang YY, Laruelle M, Abi-Dargham A. Dopamine depletion and in vivo binding of PET D1 receptor radioligands: implications for imaging studies in schizophrenia. Neuropsychopharmacology 2003; 28:1703-11. [PMID: 12813475 DOI: 10.1038/sj.npp.1300224] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent positron emission tomography (PET) studies have assessed the level of dopamine (DA) D1 receptors in the prefrontal cortex (PFC) in patients with schizophrenia and have generated contradictory findings. In the PFC of patients with schizophrenia, the binding potential (BP) of [11C]NNC 112 has been reported as increased, while the BP of [11C]SCH 23390 was reported as decreased or unchanged. In this study, the effect of acute and subchronic DA depletion on the in vivo binding of [11C]NNC 112 and [3H]SCH 23390 was evaluated in rats. Acute DA depletion did not affect [11C]NNC 112 in vivo binding, but paradoxically decreased [3H]SCH 23390 in vivo binding. Subchronic DA depletion was associated with increased [11C]NNC 112 in vivo binding and decreased [3H]SCH 23390 in vivo binding. Together, these data demonstrate that the in vivo binding of these radiotracers is differentially affected by changes in endogenous DA tone, and suggest that alterations in the binding of these tracers in the PFC of patients with schizophrenia might reflect changes in D1 receptors secondary to sustained deficit in prefrontal DA function.
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Affiliation(s)
- Ningning Guo
- Department of Psychiatry, Columbia University and New York State Psychiatric Institute, New York, NY 10032, USA.
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Eder DN, Zdravkovic M, Wildschiødtz G. Selective alterations of the first NREM sleep cycle in humans by a dopamine D1 receptor antagonist (NNC-687). J Psychiatr Res 2003; 37:305-12. [PMID: 12765853 DOI: 10.1016/s0022-3956(03)00007-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This paper details the first study of the effects of dopamine D1 receptor antagonism on the regulation of human sleep EEG (electroencephalogram). The investigational drug NNC-687 (NNC 01-0687/CEE 03-310) was administered to 20 healthy young men in doses of 5, 10, and 15 mg in a double blinded, placebo controlled, crossover design. In rats, dopamine D1 receptor antagonism can produce large increases in the amounts of both rapid eye-movement (REM) and non-rapid eye-movement (NREM) sleep. In this study, drug effects were most prominent in the first NREM period. D1 antagonism markedly reduced the peak-amplitude of delta EEG waves but increased their instantaneous frequency as well as enhancing the total number, incidence, and burst-duration of sleep spindles. The length of the first NREM period was increased up to 47% over baseline. Despite these large increases in NREM sleep time, the amount of delta EEG power accumulated over the first NREM period was conserved at baseline levels. We note that the sleep-EEG profile of D1 antagonism is very similar to that of GABAA (gamma-aminobutyric acid) receptor modulators and suggest that D1 antagonism may alter the properties of the neuronal networks which generate delta and spindle, and K-complex EEG waveforms through the upstream modulation of GABAA receptor activity.
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Affiliation(s)
- Derek N Eder
- Göteborg University, Institute of Clinical Neuroscience, Section of Clinical Neurophysiology, Blå Stråket 7, vån 3, SU/Sahlgrenska University Hospital, SE 413 45 Göteborg, Sweden.
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Trimble KM, Bell R, King DJ. Effects of the selective dopamine D(1) antagonists NNC 01-0112 and SCH 39166 on latent inhibition in the rat. Physiol Behav 2002; 77:115-23. [PMID: 12213509 DOI: 10.1016/s0031-9384(02)00814-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dopamine D(1) receptor blockade does not appear to be a prerequisite for antipsychotic activity since many clinically effective antipsychotics have little or no affinity for this receptor subtype. Clozapine, however, which has minimal liability for extrapyramidal symptoms, possesses affinities of similar order for D(1) and D(2) receptors. In earlier animal models used to predict antipsychotic effect, selective D(1) antagonists have shown effects similar to standard antipsychotics with preferential D(2) or mixed D(1)/D(2) antagonism. We investigated the effects of haloperidol (0.1 mg/kg) and two selective D(1) antagonists, NNC 01-0112 (0.05, 0.1 and 0.2 mg/kg) and SCH 39166 (0.02, 0.2 and 2.0 mg/kg), on latent inhibition (LI) in rats. LI is a behavioural paradigm in which repeated nonreinforced preexposure to a stimulus retards subsequent associations to that stimulus. Disrupted LI has been suggested as a model for the attentional deficits in schizophrenia. Using preexposure to a flashing light stimulus, which subsequently served as a conditioned stimulus for suppression of water licking, we demonstrated a clear LI effect with haloperidol but with neither of the two D(1) antagonists. Since selective D(1) antagonists are not clinically effective, these results add further credibility for the relevance of LI as an animal model of psychosis.
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Affiliation(s)
- Karen M Trimble
- Department of Therapeutics and Pharmacology, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK
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36
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Abstract
Studies in nonhuman primates documented that appropriate stimulation of dopamine (DA) D1 receptors in the dorsolateral prefrontal cortex (DLPFC) is critical for working memory processing. The defective ability of patients with schizophrenia at working memory tasks is a core feature of this illness. It has been postulated that this impairment relates to a deficiency in mesocortical DA function. In this study, D1 receptor availability was measured with positron emission tomography and the selective D1 receptor antagonist [11C]NNC 112 in 16 patients with schizophrenia (seven drug-naive and nine drug-free patients) and 16 matched healthy controls. [11C]NNC 112 binding potential (BP) was significantly elevated in the DLPFC of patients with schizophrenia (1.63 +/- 0.39 ml/gm) compared with control subjects (1.27 +/- 0.44 ml/gm; p = 0.02). In patients with schizophrenia, increased DLPFC [11C]NNC 112 BP was a strong predictor of poor performance at the n-back task, a test of working memory. These findings confirm that alteration of DLPFC D1 receptor transmission is involved in working memory deficits presented by patients with schizophrenia. Increased D1 receptor availability observed in patients with schizophrenia might represent a compensatory (but ineffective) upregulation secondary to sustained deficiency in mesocortical DA function.
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Hirvonen J, Någren K, Kajander J, Hietala J. Measurement of cortical dopamine d1 receptor binding with 11C[SCH23390]: a test-retest analysis. J Cereb Blood Flow Metab 2001; 21:1146-50. [PMID: 11598491 DOI: 10.1097/00004647-200110000-00002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
[11C]SCH 23390 is a standard ligand for positron emission tomography (PET) studies on striatal dopamine D1 receptors. Its usefulness for cortical D1 receptor quantification in human PET studies has been questioned but has not been addressed previously. The authors tested the reproducibility of [11C]SCH 23390 binding potential (BP) in cortical areas in five healthy volunteers using three-dimensional PET. Measurement of D1 receptor BP was reproducible in basal ganglia, as well as in all cortical areas studied (intraclass correlation coefficients between 0.81 and 0.92). The absolute variability in cortical areas was 9.21% +/- 0.07%. The reproducibility of cortical D1 receptor BP measurement with [11C]SCH 23390 is equal to that observed with a more recent D1-ligand, [11C]NNC 112. [11C]NNC 112 produces slightly higher specific-to-nonspecific binding ratios but has markedly slower kinetics resulting in a need for a longer scan time. These aspects should be considered when designing studies on the cortical D1-like receptors.
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Affiliation(s)
- J Hirvonen
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Finland
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38
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Arakawa H, Kodama H, Yamaguchi I, Matsuoka N. A dopamine D(1/5) receptor antagonist, SCH23390, prevents stress-induced sudden death in cardiomyopathic hamsters. Pharmacol Biochem Behav 2000; 66:707-12. [PMID: 10973507 DOI: 10.1016/s0091-3057(00)00287-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stress is known to have an impact on the development of life-threatening cardiovascular dysfunction. We have previously demonstrated that repeated exposure to cold-immobilization stress had lethal effects on cardiomyopathic Syrian hamsters (BIO 14.6), and that stress-induced sudden death was prevented by daily treatment with propranolol, suggesting an important role of sympathetic nerves in the etiology of stress-induced cardiac sudden death. In an attempt to clarify further the mechanisms of the sudden death, in the present study we investigated the effects of D(1/5) receptor blockade by SCH23390 on the sudden death of cardiomyopathic hamsters. In accordance with our previous results, repeated exposure for 5 days to cold-immobilization stress induced a lethal effect in the cardiomyopathic hamsters but not in control healthy hamsters. SCH23390 (0.1-10 mg/kg, IP), administered just before the exposure for 5 consecutive days, dose-dependently and significantly prevented the lethal effects of the stress. Furthermore, it was demonstrated that the drug significantly reduced the increase in the weights of the adrenal and kidneys observed in the stressed-cardiomyopathic hamsters. On the other hand, specific D(2) antagonist haloperidol (0. 1-10 mg/kg) failed to prevent the stress-induced sudden death and minimally affected the increase in organ weights. Collectively, these results suggest that D(1/5) receptors had an important role in the etiology of stress-induced cardiac sudden death of the cardiomyopathic hamsters, and provide the first experimental evidence of the potential therapeutic values of D(1/5) antagonists against cardiac sudden death associated with stress.
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Affiliation(s)
- H Arakawa
- Basic Research Group, Tsukuba Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., Tsukuba, Ibaraki, Japan
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Abstract
Several groups have provided evidence that positron emission tomography (PET) and single-photon emission computed tomography (SPECT) neuroreceptor imaging techniques might be applied to measure acute fluctuations in dopamine (DA) synaptic concentration in the living human brain. Competition between DA and radioligands for binding to D2 receptor is the principle underlying this approach. This new application of neuroreceptor imaging provides a dynamic measurement of neurotransmission that is likely to be informative to our understanding of neuropsychiatric conditions. This article reviews and discusses the body of data supporting the feasibility and potential of this imaging paradigm. Endogenous competition studies performed in rodents, nonhuman primates, and humans are first summarized. After this overview, the validity of the model underlying the interpretation of these imaging data is critically assessed. The current reference model is defined as the occupancy model, since changes in radiotracer binding potential (BP) are assumed to be directly caused by changes in occupancy of D2 receptors by DA. Experimental data supporting this model are presented. The evidence that manipulation of DA synaptic levels induces change in the BP of several D2 radiotracers (catecholamines and benzamides) is unequivocal. The fact that these changes in BP are mediated by changes in DA synaptic concentration is well documented. The relationship between the magnitude of BP changes measured with PET or SPECT and the magnitude of changes in DA concentration measured by microdialysis supports the use of these noninvasive techniques to measure changes in neurotransmission. On the other hand, several observations remain unexplained. First, the amphetamine-induced changes in the BP of D2 receptor antagonists [123I]IBZM and [11C]raclopride last longer than amphetamine-induced changes in DA extracellular concentration. Second, nonbenzamide D2 receptor antagonists, such as spiperone and pimozide, are not affected by changes in DA release, or are affected in a direction opposite to that predicted by the occupancy model. Similar observations are reported with D1 radiotracers. These results suggest that the changes in BP following changes in DA concentration might not be fully accounted by a simple occupancy model. Specifically, the data are reviewed supporting that agonist-mediated receptor internalization might play an important role in characterizing receptor-ligand interactions. Finally, it is proposed that a better understanding of the mechanism underlying the effects observed with benzamides is essential to develop this imaging technique to other receptor systems.
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Affiliation(s)
- M Laruelle
- Department of Psychiatry and Radiology, Columbia University College of Physicians and Surgeons and New York State Psychiatric Institute, New York 10032, USA
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Abi-Dargham A, Martinez D, Mawlawi O, Simpson N, Hwang DR, Slifstein M, Anjilvel S, Pidcock J, Guo NN, Lombardo I, Mann JJ, Van Heertum R, Foged C, Halldin C, Laruelle M. Measurement of striatal and extrastriatal dopamine D1 receptor binding potential with [11C]NNC 112 in humans: validation and reproducibility. J Cereb Blood Flow Metab 2000; 20:225-43. [PMID: 10698059 DOI: 10.1097/00004647-200002000-00003] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
To evaluate the postulated role of extrastriatal D1 receptors in human cognition and psychopathology requires an accurate and reliable method for quantification of these receptors in the living human brain. [11C]NNC 112 is a promising novel radiotracer for positron emission tomography imaging of the D1 receptor. The goal of this study was to develop and evaluate methods to derive D1 receptor parameters in striatal and extrastriatal regions of the human brain with [11C]NNC 112. Six healthy volunteers were studied twice. Two methods of analysis (kinetic and graphical) were applied to 12 regions (neocortical, limbic, and subcortical regions) to derive four outcome measures: total distribution volume, distribution volume ratio, binding potential (BP), and specific-to-nonspecific equilibrium partition coefficient (k3/k4). Both kinetic and graphic analyses provided BP and k3/k4 values in good agreement with the known distribution of D1 receptors (striatum > limbic regions = neocortical regions > thalamus). The identifiability of outcome measures derived by kinetic analysis was excellent. Time-stability analysis indicated that 90 minutes of data collection generated stable outcome measures. Derivation of BP and k3/k4 by kinetic analysis was highly reliable, with intraclass correlation coefficients (ICCs) of 0.90+/-0.06 (mean +/- SD of 12 regions) and 0.84+/-0.11, respectively. The reliability of these parameters derived by graphical analysis was lower, with ICCs of 0.72+/-0.17 and 0.58+/-0.21, respectively. Noise analysis revealed a noise-dependent bias in the graphical but not the kinetic analysis. In conclusion, kinetic analysis of [11C]NNC 112 uptake provides an appropriate method with which to derive D1 receptor parameters in regions with both high (striatal) and low (extrastriatal) D1 receptor density.
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Affiliation(s)
- A Abi-Dargham
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York, USA
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Abi-Dargham A, Simpson N, Kegeles L, Parsey R, Hwang DR, Anjilvel S, Zea-Ponce Y, Lombardo I, Van Heertum R, Mann JJ, Foged C, Halldin C, Laruelle M. PET studies of binding competition between endogenous dopamine and the D1 radiotracer [11C]NNC 756. Synapse 1999; 32:93-109. [PMID: 10231129 DOI: 10.1002/(sici)1098-2396(199905)32:2<93::aid-syn3>3.0.co;2-c] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
NNC 756 ((+)-8-chloro-5-(2,3-dihydrobenzofuran-7-yl)-7-hydroxy-3-methyl-2,3,4,5- tetrahydro-1H-3-benzazepine) is a new high affinity dopamine (DA) D1 receptor antagonist. Labeled with C-11, it has been used as a PET radiotracer to visualize D1 receptors both in striatal and extrastriatal areas, such as the prefrontal cortex. The goal of this study was to evaluate several methods for derivation of D1 receptor binding potential (BP) with [11C]NNC 756 in baboons, and to use these methods to assess the vulnerability of [11C]NNC 756 binding to competition by endogenous DA. A three-compartment model provided a good fit to PET data acquired following a single bolus injection. BP values obtained with this analysis were in good agreement with values derived from in vitro studies. BP values measured following injection of the potent DA releaser amphetamine (1 mg/kg, n=2) were similar to values measured under control conditions. Kinetic parameters derived from single bolus experiments were used to design a bolus plus continuous infusion administration protocol aimed at achieving a state of sustained binding equilibrium. Injection of amphetamine during sustained equilibrium did not affect [11C]NNC 756 binding. Similar results were observed with another D1 radiotracer, [11C]SCH 23390. Doses of amphetamine used in this study are known to reduce by 20-40% the binding potential of several D2 receptors radiotracers. Therefore, the absence of displacement of [11C]NNC 756 by an endogenous DA surge may indicate important differences between D1 and D2 receptors in vivo, such as differences in proportion of high affinity states not occupied by DA at baseline. These findings may also imply that a simple binding competition model is inadequate to account for the effects of manipulation of endogenous DA levels on the in vivo binding of radiolabeled antagonists.
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Affiliation(s)
- A Abi-Dargham
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York State Psychiatric Institute, New York 10032, USA.
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Grondin R, Doan VD, Grégoire L, Bédard PJ. D1 receptor blockade improves L-dopa-induced dyskinesia but worsens parkinsonism in MPTP monkeys. Neurology 1999; 52:771-6. [PMID: 10078726 DOI: 10.1212/wnl.52.4.771] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine whether dopamine (DA) D1 or DA D2 receptors are associated predominantly with the antiparkinsonian versus the dyskinetic effect of levodopa. METHODS The authors used four L-dopa-primed, dyskinetic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-exposed monkeys to test whether acute and selective blockade of the DA D1 receptor subtype, using SCH 23390 and NNC 01-112, could reduce L-dopa-induced dyskinesias without altering the relief of symptoms. Blockade of DA receptors using sulpiride (D2) and clozapine (D1-D2-like) was studied for comparison. RESULTS With the notable exception of the lowest dose of clozapine tested, coadministration of DA D1 or D2 antidopaminergic agents with L-dopa reduced the L-dopa-induced dyskinesias but also caused a return of parkinsonian disability. Prolonged latencies from intake of a single oral dose of L-dopa to turning "on," decreased duration of the "on" state, and a complete failure to induce benefit was also observed. CONCLUSION Low-dose clozapine could be an effective adjunct to reduce L-dopa-induced dyskinesias without altering the relief of parkinsonian symptoms. Interactions with many neurotransmitter systems may explain the better pharmacologic profile of clozapine, including DA D4 (rather than D1), serotonin, acetylcholine, and noradrenaline. Neither dyskinesias nor antiparkinsonian effects can be ascribed solely to the D2 or D1 receptor. Thus, some cooperation between the two receptors appears necessary for these behavioral effects.
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Affiliation(s)
- R Grondin
- CHUL Research Centre, Department of Medicine, Faculty of Medicine, Laval University, Ste-Foy (Quebec), Canada
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Waterhouse RN, Collier TL, O'Brien JC. Synthesis of 1-(trans-[123I]Iodopropen-2-yl)-4-(4-cyanophenoxy-methyl)piperidine: A selective sigma receptor radioligand for SPECT. J Labelled Comp Radiopharm 1998. [DOI: 10.1002/(sici)1099-1344(199603)38:3<215::aid-jlcr834>3.0.co;2-f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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44
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Lee Collier T, O'Brien JC, Waterhouse RN. Synthesis of [18F]-1-(3-Fluoropropyl)-4-(4-cyanophenoxymethyl)-piperidine: A potential sigma-1 receptor radioligand for PET. J Labelled Comp Radiopharm 1998. [DOI: 10.1002/(sici)1099-1344(199609)38:9<785::aid-jlcr901>3.0.co;2-b] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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45
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Waterhouse RN, Collier TL, O'Brien JC. Synthesis of a selective sigma receptor radioligand for SPECT: [123I]-1-(2-hydroxyethyl)-4-(4-iodophenoxymethyl)piperidine. J Labelled Comp Radiopharm 1998. [DOI: 10.1002/(sici)1099-1344(199607)38:7<595::aid-jlcr882>3.0.co;2-a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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46
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Efange SM, Mash DC, Khare AB, Ouyang Q. Modified ibogaine fragments: synthesis and preliminary pharmacological characterization of 3-ethyl-5-phenyl-1,2,3,4,5, 6-hexahydroazepino[4,5-b]benzothiophenes. J Med Chem 1998; 41:4486-91. [PMID: 9804688 DOI: 10.1021/jm980156y] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Five phenyl-substituted derivatives and analogues of 1,2,3,4,5, 6-hexahydroazepino[4,5-b]indole, 5, a major fragment of ibogaine (1), were synthesized and tested for binding to monoamine transporters, the NMDA receptor-coupled cation channel, and dopamine and opioid receptors. All five derivatives, 9 and 17a-d, displayed 8-10-fold higher affinity at the DA transporter than ibogaine and noribogaine (4). At the serotonin transporter, two compounds (9 and 17a) exhibited higher potency than ibogaine, while the rest had weaker binding affinities than the lead compound. In keeping with their structural similarity to ibogaine, all five compounds displayed weak to poor affinity for dopamine D1 and D2 receptors. However, two compounds, 17a,c, demonstrated moderate binding affinities at dopamine D3 receptors. All five compounds displayed weak to poor affinities for mu and kappa opioid receptors and for the NMDA receptor-coupled cation channel. Despite the qualitative differences, derivatives and analogues of 5may serve as useful substitutes for ibogaine.
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Affiliation(s)
- S M Efange
- Departments of Radiology, Medicinal Chemistry, and Neurosurgery, Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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47
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Hauber W, Lutz S, Münkle M. The effects of globus pallidus lesions on dopamine-dependent motor behaviour in rats. Neuroscience 1998; 86:147-57. [PMID: 9692750 DOI: 10.1016/s0306-4522(98)00009-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Motor effects of bilateral lesions of the globus pallidus induced by quinolinic acid (30 and 60 nmol in 0.5 microl) were investigated in rats. Globus pallidus lesions with 60 nmol quinolinic acid produced a significant reduction of spontaneous motor activity measured by a reduced locomotor activity in an open field and by a reduced sniffing activity in an experimental chamber. In addition, D-amphetamine (1 mg/kg, i.p.)-induced hyperlocomotion and D-amphetamine (3 mg/kg, i.p.)-induced stereotyped sniffing were significantly reduced in animals with quinolinic acid lesions (60 nmol). Globus pallidus lesions with 60 nmol quinolinic acid potently reversed catalepsy induced by systemic administration of the dopamine D1 receptor antagonist SCH23390 (0.75 and 1 mg/kg, i.p.) or the dopamine D2 receptor antagonist raclopride (1.25 and 5 mg/kg, i.p.), while lesions with 30 nmol quinolinic acid exerted anti-cataleptic effects which were only partly significant. In line with current models of basal ganglia functions, these findings indicate that inactivation of the globus pallidus reduced spontaneous motor activity and motor hyperactivity after dopamine receptor stimulation. However, the present data also demonstrate that inactivation of the globus pallidus reversed motor hypoactivity induced by a blockade of dopamine D1 and D2 receptors. Therefore, a more complex functional model of the globus pallidus is required to account for the opposite effects on motor behaviour observed after lesions of this basal ganglia nucleus.
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Affiliation(s)
- W Hauber
- University of Stuttgart, Institute of Biology, Department of Animal Physiology, Germany
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Foged C, Halldin C, Swahn CG, Ginovart N, Karlsson P, Lundkvist C, Farde L. [11C]NNC 22-0215, a metabolically stable dopamine D1 radioligand for PET. Nucl Med Biol 1998; 25:503-8. [PMID: 9720669 DOI: 10.1016/s0969-8051(98)00010-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
NNC 22-0215 has been found to be a metabolically stable dopamine D1 antagonist with high affinity and selectivity for D1 receptors in vitro. We prepared [11C]NNC 22-0215 with a specific radioactivity of about 50 GBq/micromol at time of administration. In PET experiments with [11C]NNC 22-0215 there was a rapid uptake of radioactivity in the cynomolgus monkey brain (1.8% of total radioactivity injected). Radioactivity accumulated most markedly in the striatum and the neocortex. The striatum to cerebellum ratio was about 4, with specific binding that remained at a plateau level from 50 min to 100 min after injection. Binding in the striatum and neocortex was markedly displaced by SCH 23390, whereas binding in the cerebellum was not reduced. Metabolite studies showed that about 80% of the radioactivity in the monkey plasma represented unchanged radioligand 30 min after injection. The rate of metabolism in monkey plasma in vivo was also determined for a series of structurally related 11C-labelled benzazepines, previously used as dopamine D1 receptor ligands for PET. Results indicate a significantly slower rate of metabolism for [11C]NNC 22-0215 than for any of the previously labelled benzazepines. Thus [11C]NNC 22-0215 has potential for imaging of selective binding to the dopamine D1 receptors in the human brain with high count rates at time of equilibrium.
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Affiliation(s)
- C Foged
- Karolinska Institutet, Department of Clinical Neuroscience, Karolinska Hospital, Stockholm, Sweden.
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Salmi P, Ahlenius S. Dihydrexidine produces hypothermia in rats via activation of dopamine D1 receptors. Neurosci Lett 1997; 236:57-9. [PMID: 9404951 DOI: 10.1016/s0304-3940(97)00740-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The selective dopamine D1 receptor agonist dihydrexidine (2.0-8.0 mg/kg, s.c.) caused a dose-dependent decrease in core temperature in rats. The hypothermia produced by dihydrexidine (4.0 mg/kg), was completely blocked by the dopamine D1 receptor antagonists SCH 23390 (0.1 mg/kg, s.c.) or NNC 687 (4.0 mg/kg, s.c.), but not by the dopamine D2/3 receptor antagonist raclopride (0.2 mg/kg, s.c.). Neither of the dopamine antagonists by themselves produced any effects on core temperature. The present results provide important evidence for the notion that activation of dopamine D1 receptors induces hypothermia in rats.
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Affiliation(s)
- P Salmi
- Department of Psychology, Stockholm University, Sweden.
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50
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Shiue CY, Shiue GG, Zhang SX, Wilder S, Greenberg JH, Benard F, Wortman JA, Alavi AA. N-(N-benzylpiperidin-4-yl)-2-[18F]fluorobenzamide: a potential ligand for PET imaging of sigma receptors. Nucl Med Biol 1997; 24:671-6. [PMID: 9352539 DOI: 10.1016/s0969-8051(97)00097-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Four nitro- and fluorobenzamides (1-4) have been synthesized in good yields from nitro- and fluoro-substituted benzoyl chloride with 4-amino-1-benzylpiperidine. In vitro studies showed that these compounds have high affinities to sigma receptors. N-(N-Benzylpiperidin-4-yl)-2-fluorobenzamide (3), in particular, bound to sigma receptors with high affinity (Ki = 3.4 nM, guinea pig brain membranes) and high selectivity (sigma-2/sigma-1 = 120). It was, therefore, labeled with 18F and evaluated as a sigma receptor radioligand. N-(N-Benzylpiperidin-4-yl)-2-[18F]fluorobenzamide (3a) was synthesized in one step by nucleophile substitution of the 2-nitro precursor (1) with [18F]fluoride in DMSO at 140 degrees C for 20 min followed by purification with HPLC in 4-10% yield (decay corrected). The synthesis time was 90 min and the specific activity was 0.4-1.0 Ci/mumol. Tissue distribution in mice revealed that the uptakes of 3a in the brain, heart, liver, lungs, spleen, kidneys and small intestine were high, and the radioactivity in these organs remained constant from 60 to 120 min post-injection. The radioactivity in the bone did not significantly increase, suggesting in vivo defluorination may not be the major route of metabolism of 3a in mice. Blocking studies with haloperidol in rats indicated that the uptake of compound 3a in the rat brain was selective to haloperidol-sensitive sigma sites. These results suggest that compound 3a is a potent sigma receptor radioligand and may be a potential ligand for PET imaging of sigma receptors in humans.
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Affiliation(s)
- C Y Shiue
- Department of Radiology, University of Pennsylvania, Philadelphia 19104, USA
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