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Zhou YP, Normandin MD, Belov V, Macdonald-Soccorso MT, Moon SH, Sun Y, El Fakhri G, Guehl NJ, Brugarolas P. Evaluation of trans- and cis-4-[ 18F]Fluorogabapentin for Brain PET Imaging. ACS Chem Neurosci 2023; 14:4208-4215. [PMID: 37947793 DOI: 10.1021/acschemneuro.3c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023] Open
Abstract
Gabapentin, a selective ligand for the α2δ subunit of voltage-dependent calcium channels, is an anticonvulsant medication used in the treatment of neuropathic pain, epilepsy, and other neurological conditions. We recently described two radiofluorinated derivatives of gabapentin (trans-4-[18F]fluorogabapentin, [18F]tGBP4F, and cis-4-[18F]fluorogabapentin, [18F]cGBP4F) and showed that these compounds accumulate in the injured nerves in a rodent model of neuropathic pain. Given the use of gabapentin in brain diseases, here we investigate whether these radiofluorinated derivatives of gabapentin can be used for imaging α2δ receptors in the brain. Specifically, we developed automated radiosynthesis methods for [18F]tGBP4F and [18F]cGBP4F and conducted dynamic PET imaging in adult rhesus macaques with and without preadministration of pharmacological doses of gabapentin. Both radiotracers showed very high metabolic stability, negligible plasma protein binding, and slow accumulation in the brain. [18F]tGBP4F, the isomer with higher binding affinity, showed low brain uptake and could not be displaced, whereas [18F]cGBP4F showed moderate brain uptake and could be partially displaced. Kinetic modeling of brain regional time-activity curves using a metabolite-corrected arterial input function shows that a one-tissue compartment model accurately fits the data. Graphical analysis using Logan or multilinear analysis 1 produced similar results as compartmental modeling, indicating robust quantification. This study advances our understanding of how gabapentinoids work and provides an important advancement toward imaging α2δ receptors in the brain.
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Affiliation(s)
- Yu-Peng Zhou
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Marc D Normandin
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Vasily Belov
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Marina T Macdonald-Soccorso
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Yang Sun
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Nicolas J Guehl
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
| | - Pedro Brugarolas
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, United States
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2
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Zhou YP, Normandin MD, Belov V, Macdonald-Soccorso MT, Moon SH, Sun Y, Fakhri GE, Guehl NJ, Brugarolas P. Evaluation of trans- and cis-4-[ 18F]fluorogabapentin for brain PET imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555353. [PMID: 37732236 PMCID: PMC10508714 DOI: 10.1101/2023.09.01.555353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Gabapentin, a selective ligand for the α2δ subunit of voltage-dependent calcium channels, is an anticonvulsant medication used in the treatment of neuropathic pain, epilepsy and other neurological conditions. We recently described two radiofluorinated derivatives of gabapentin (trans-4-[18F]fluorogabapentin, [18F]tGBP4F, and cis-4-[18F]fluorogabapentin, [18F]cGBP4F) and showed that these compounds accumulate in the injured nerves in a rodent model of neuropathic pain. Given the use of gabapentin in brain diseases, here we investigate whether these radiofluorinated derivatives of gabapentin can be used for imaging α2δ receptors in the brain. Specifically, we developed automated radiosynthesis methods for [18F]tGBP4F and [18F]cGBP4F and conducted dynamic PET imaging in adult rhesus macaques with and without preadministration of pharmacological doses of gabapentin. Both radiotracers showed very high metabolic stability, negligible plasma protein binding and slow accumulation in the brain. [18F]tGBP4F, the isomer with higher binding affinity, showed low brain uptake and could not be displaced whereas [18F]cGBP4F showed moderate brain uptake and could be partially displaced. Kinetic modeling of brain regional time-activity curves using a metabolite-corrected arterial input function shows that a 1-tissue compartment model accurately fits the data. Graphical analysis using Logan or multilinear analysis 1 produced similar results as compartmental modeling indicating robust quantification. This study advances our understanding of how gabapentinoids work and provides an important advancement towards imaging α2δ receptors in the brain.
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Affiliation(s)
- Yu-Peng Zhou
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Marc D. Normandin
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Vasily Belov
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Marina T. Macdonald-Soccorso
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Sung-Hyun Moon
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Yang Sun
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Georges El Fakhri
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Nicolas J. Guehl
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Pedro Brugarolas
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
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3
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Kozai D, Numoto N, Nishikawa K, Kamegawa A, Kawasaki S, Hiroaki Y, Irie K, Oshima A, Hanzawa H, Shimada K, Kitano Y, Fujiyoshi Y. Recognition mechanism of a novel gabapentinoid drug, mirogabalin, for recombinant human α 2δ1, a voltage-gated calcium channel subunit. J Mol Biol 2023; 435:168049. [PMID: 36933823 DOI: 10.1016/j.jmb.2023.168049] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/22/2023] [Accepted: 03/12/2023] [Indexed: 03/17/2023]
Abstract
Mirogabalin is a novel gabapentinoid drug with a hydrophobic bicyclo substituent on the γ-aminobutyric acid moiety that targets the voltage-gated calcium channel subunit α2δ1. Here, to reveal the mirogabalin recognition mechanisms of α2δ1, we present structures of recombinant human α2δ1 with and without mirogabalin analyzed by cryo-electron microscopy. These structures show the binding of mirogabalin to the previously reported gabapentinoid binding site, which is the extracellular dCache_1 domain containing a conserved amino acid binding motif. A slight conformational change occurs around the residues positioned close to the hydrophobic group of mirogabalin. Mutagenesis binding assays identified that residues in the hydrophobic interaction region, in addition to several amino acid binding motif residues around the amino and carboxyl groups of mirogabalin, are critical for mirogabalin binding. The A215L mutation introduced to decrease the hydrophobic pocket volume predictably suppressed mirogabalin binding and promoted the binding of another ligand, L-Leu, with a smaller hydrophobic substituent than mirogabalin. Alterations of residues in the hydrophobic interaction region of α2δ1 to those of the α2δ2, α2δ3, and α2δ4 isoforms, of which α2δ3 and α2δ4 are gabapentin-insensitive, suppressed the binding of mirogabalin. These results support the importance of hydrophobic interactions in α2δ1 ligand recognition.
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Affiliation(s)
- Daisuke Kozai
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Japan Biological Informatics Consortium, 2-4-32 Aomi, Koto-ku, Tokyo 135-0063, Japan; Advanced Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8501, Japan.
| | - Nobutaka Numoto
- Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8501, Japan.
| | - Kouki Nishikawa
- CeSPIA Inc., 2-1-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan; Joint Research Course for Advanced Biomolecular Characterization, Faculty of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
| | - Akiko Kamegawa
- Advanced Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8501, Japan; CeSPIA Inc., 2-1-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
| | - Shohei Kawasaki
- Daiichi Sankyo RD Novare Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Yoko Hiroaki
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Japan Biological Informatics Consortium, 2-4-32 Aomi, Koto-ku, Tokyo 135-0063, Japan.
| | - Katsumasa Irie
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Atsunori Oshima
- Cellular and Structural Physiology Institute (CeSPI), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Institute for Glyco-core Research (iGCORE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
| | - Hiroyuki Hanzawa
- Daiichi Sankyo RD Novare Co., Ltd., 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan.
| | - Kousei Shimada
- Daiichi Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan.
| | - Yutaka Kitano
- Daiichi Sankyo Co., Ltd., 1-2-58 Hiromachi, Shinagawa-ku, Tokyo 140-8710, Japan.
| | - Yoshinori Fujiyoshi
- Advanced Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8501, Japan; CeSPIA Inc., 2-1-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan.
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Chen L, Qu Q, Ran CK, Wang W, Zhang W, He Y, Liao LL, Ye JH, Yu DG. Photocatalytic Carboxylation of C-N Bonds in Cyclic Amines with CO 2 by Consecutive Visible-Light-Induced Electron Transfer. Angew Chem Int Ed Engl 2023; 62:e202217918. [PMID: 36680762 DOI: 10.1002/anie.202217918] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Visible-light photocatalytic carboxylation with CO2 is highly important. However, it still remains challenging for reluctant substrates with low reduction potentials. Herein, we report a novel photocatalytic carboxylation of C-N bonds in cyclic amines with CO2 via consecutive photo-induced electron transfer (ConPET). It is also the first photocatalytic reductive ring-opening reaction of azetidines, pyrrolidines and piperidines. This strategy is practical to transform a variety of easily available cyclic amines to valuable β-, γ-, δ- and ϵ-amino acids in moderate-to-excellent yields. Moreover, the method also features mild and transition-metal-free conditions, high selectivity, good functional-group tolerance, facile scalability and product derivations. Mechanistic studies indicate that the ConPET might be the key to generating highly reactive photocatalysts, which enable the reductive activation of cyclic amines to generate carbon radicals and carbanions as the key intermediates.
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Affiliation(s)
- Lin Chen
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Quan Qu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Chuan-Kun Ran
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Wei Wang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Wei Zhang
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Yi He
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Li-Li Liao
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400030, P. R. China
| | - Jian-Heng Ye
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Da-Gang Yu
- Key Laboratory of Green Chemistry & Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China.,State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, P. R. China
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5
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Alsanie WF, Abdelrahman S, Alhomrani M, Gaber A, Habeeballah H, Alkhatabi HA, Felimban RI, Hauser CAE, Tayeb HH, Alamri AS, Raafat BM, Anwar S, Alswat KA, Althobaiti YS, Asiri YA. Prenatal Exposure to Gabapentin Alters the Development of Ventral Midbrain Dopaminergic Neurons. Front Pharmacol 2022; 13:923113. [PMID: 35942222 PMCID: PMC9356305 DOI: 10.3389/fphar.2022.923113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Gabapentin is widely prescribed as an off-label drug for the treatment of various diseases, including drug and alcohol addiction. Approximately 83–95% of the usage of gabapentin is off-label, accounting for more than 90% of its sales in the market, which indicates an alarming situation of drug abuse. Such misuse of gabapentin has serious negative consequences. The safety of the use of gabapentin in pregnant women has always been a serious issue, as gabapentin can cross placental barriers. The impact of gabapentin on brain development in the fetus is not sufficiently investigated, which poses difficulties in clinical decisions regarding prescriptions.Methods: The consequences effect of prenatal gabapentin exposure on the development of ventral midbrain dopaminergic neurons were investigated using three-dimensional neuronal cell cultures. Time-mated Swiss mice were used to isolate embryos. The ventral third of the midbrain was removed and used to enrich the dopaminergic population in 3D cell cultures that were subsequently exposed to gabapentin. The effects of gabapentin on the viability, ATP release, morphogenesis and genes expression of ventral midbrain dopaminergic neurons were investigated.Results: Gabapentin treatment at the therapeutic level interfered with the neurogenesis and morphogenesis of vmDA neurons in the fetal brain by causing changes in morphology and alterations in the expression of key developmental genes, such as Nurr1, Chl1, En1, Bdnf, Drd2, and Pitx3. The TH + total neurite length and dominant neurite length were significantly altered. We also found that gabapentin could halt the metabolic state of these neuronal cells by blocking the generation of ATP.Conclusion: Our findings clearly indicate that gabapentin hampers the morphogenesis and development of dopaminergic neurons. This implies that the use of gabapentin could lead to serious complications in child-bearing women. Therefore, caution must be exercised in clinical decisions regarding the prescription of gabapentin in pregnant women.
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Affiliation(s)
- Walaa F. Alsanie
- Department of Clinical Laboratories Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
- Centre of Biomedical Sciences Research (CBSR), Deanship of Scientific Research, Taif University, Taif, Saudi Arabia
- *Correspondence: Walaa F. Alsanie,
| | - Sherin Abdelrahman
- Laboratory for Nanomedicine, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology, (KAUST), Jeddah, Saudi Arabia
| | - Majid Alhomrani
- Department of Clinical Laboratories Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
- Centre of Biomedical Sciences Research (CBSR), Deanship of Scientific Research, Taif University, Taif, Saudi Arabia
| | - Ahmed Gaber
- Centre of Biomedical Sciences Research (CBSR), Deanship of Scientific Research, Taif University, Taif, Saudi Arabia
- Department of Biology, College of Science, Taif University, Taif, Saudi Arabia
| | - Hamza Habeeballah
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences in Rabigh, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Heba A. Alkhatabi
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah, Saudi Arabia
- King Fahd Medical Research Centre, Hematology Research Unit, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Raed I. Felimban
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Innovation in Personalized Medicine (CIPM), 3D Bioprinting Unit, King Abdulaziz University (KAUST), Jeddah, Saudi Arabia
| | - Charlotte A. E. Hauser
- Laboratory for Nanomedicine, Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Computational Bioscience Research Center (CBRC), King Abdullah University of Science and Technology, (KAUST), Jeddah, Saudi Arabia
| | - Hossam H. Tayeb
- Department of Medical Laboratory Sciences, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Center of Innovation in Personalized Medicine (CIPM), Nanomedicine Unit, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Abdulhakeem S. Alamri
- Department of Clinical Laboratories Sciences, The Faculty of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
- Centre of Biomedical Sciences Research (CBSR), Deanship of Scientific Research, Taif University, Taif, Saudi Arabia
| | - Bassem M. Raafat
- Department of Radiological Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia
| | - Sirajudheen Anwar
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Hail, Hail, Saudi Arabia
| | - Khaled A. Alswat
- Department of Internal Medicine, School of Medicine, Taif University, Taif, Saudi Arabia
| | - Yusuf S. Althobaiti
- Department of Pharmacology and Toxicology, College of Pharmacy, Taif University, Taif, Saudi Arabia
- Addiction and Neuroscience Research Unit, Taif University, Taif, Saudi Arabia
| | - Yousif A. Asiri
- Department of Clinical Pharmacy, College of Pharmacy, Taif University, Taif, Saudi Arabia
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6
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Kunzendorf A, Saifuddin M, Poelarends GJ. Enantiocomplementary Michael Additions of Acetaldehyde to Aliphatic Nitroalkenes Catalyzed by Proline-Based Carboligases. Chembiochem 2022; 23:e202100644. [PMID: 35049100 PMCID: PMC9306545 DOI: 10.1002/cbic.202100644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/19/2022] [Indexed: 11/17/2022]
Abstract
The blockbuster drug Pregabalin is widely prescribed for the treatment of painful diabetic neuropathy. Given the continuous epidemic growth of diabetes, the development of sustainable synthesis routes for Pregabalin and structurally related pharmaceutically active γ‐aminobutyric acid (GABA) derivatives is of high interest. Enantioenriched γ‐nitroaldehydes are versatile synthons for the production of GABA derivatives, which can be prepared through a Michael‐type addition of acetaldehyde to α,β‐unsaturated nitroalkenes. Here we report that tailored variants of the promiscuous enzyme 4‐oxalocrotonate tautomerase (4‐OT) can accept diverse aliphatic α,β‐unsaturated nitroalkenes as substrates for acetaldehyde addition. Highly enantioenriched aliphatic (R)‐ and (S)‐γ‐nitroaldehydes were obtained in good yields using two enantiocomplementary 4‐OT variants. Our results underscore the synthetic potential of 4‐OT for the preparation of structurally diverse synthons for bioactive analogues of Pregabalin.
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Affiliation(s)
- Andreas Kunzendorf
- University of Groningen: Rijksuniversiteit Groningen, Chemical and Pharmaceutical Biology, NETHERLANDS
| | - Mohammad Saifuddin
- University of Groningen: Rijksuniversiteit Groningen, Chemical and Pharmaceutical Biology, NETHERLANDS
| | - Gerrit J Poelarends
- University of Groningen, Chemical and Pharmaceutical Biology, Antonius Deusinglaan 1, 9713 AV, Groningen, NETHERLANDS
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7
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Ahmad KA, Shoaib RM, Ahsan MZ, Deng MY, Ma L, Apryani E, Li XY, Wang YX. Microglial IL-10 and β-endorphin expression mediates gabapentinoids antineuropathic pain. Brain Behav Immun 2021; 95:344-361. [PMID: 33862171 DOI: 10.1016/j.bbi.2021.04.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 04/11/2021] [Accepted: 04/12/2021] [Indexed: 12/24/2022] Open
Abstract
Gabapentinoids are recommended first-line treatments for neuropathic pain. They are neuronal voltage-dependent calcium channel α2δ-1 subunit ligands and have been suggested to attenuate neuropathic pain via interaction with neuronal α2δ-1 subunit. However, the current study revealed their microglial mechanisms underlying antineuropathic pain. Intrathecal injection of gabapentin, pregabalin and mirogabalin rapidly inhibited mechanical allodynia and thermal hyperalgesia, with projected ED50 values of 30.3, 6.2 and 1.5 µg (or 176.9, 38.9 and 7.2 nmol) and Emax values of 66%, 61% and 65% MPE respectively for mechanical allodynia. Intrathecal gabapentinoids stimulated spinal mRNA and protein expression of IL-10 and β-endorphin (but not dynorphin A) in neuropathic rats with the time point parallel to their inhibition of allodynia, which was observed in microglia but not astrocytes or neurons in spinal dorsal horns by using double immunofluorescence staining. Intrathecal gabapentin alleviated pain hypersensitivity in male/female neuropathic but not male sham rats, whereas it increased expression of spinal IL-10 and β-endorphin in male/female neuropathic and male sham rats. Treatment with gabapentin, pregabalin and mirogabalin specifically upregulated IL-10 and β-endorphin mRNA and protein expression in primary spinal microglial but not astrocytic or neuronal cells, with EC50 values of 41.3, 11.5 and 2.5 µM and 34.7, 13.3 and 2.8 µM respectively. Pretreatment with intrathecal microglial metabolic inhibitor minocycline, IL-10 antibody, β-endorphin antiserum or μ-opioid receptor antagonist CTAP (but not κ- or δ-opioid receptor antagonists) suppressed spinal gabapentinoids-inhibited mechanical allodynia. Immunofluorescence staining exhibited specific α2δ-1 expression in neurons but not microglia or astrocytes in the spinal dorsal horns or cultured primary spinal cells. Thus the results illustrate that gabapentinoids alleviate neuropathic pain through stimulating expression of spinal microglial IL-10 and consequent β-endorphin.
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Affiliation(s)
- Khalil Ali Ahmad
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Rana Muhammad Shoaib
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Muhammad Zaeem Ahsan
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Meng-Yan Deng
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Le Ma
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Evhy Apryani
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Xin-Yan Li
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China
| | - Yong-Xiang Wang
- King's Lab, Shanghai Jiao Tong University School of Pharmacy, 800 Dongchuan Road, Shanghai 200240, China.
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8
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Gou X, Yu X, Bai D, Tan B, Cao P, Qian M, Zheng X, Chen L, Shi Z, Li Y, Ye F, Liang Y, Ni J. Pharmacology and Mechanism of Action of HSK16149, a Selective Ligand of α2 δ Subunit of Voltage-Gated Calcium Channel with Analgesic Activity in Animal Models of Chronic Pain. J Pharmacol Exp Ther 2020; 376:330-337. [PMID: 33293377 DOI: 10.1124/jpet.120.000315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023] Open
Abstract
Chronic pain is a public health problem because current treatments are unsatisfactory with small therapeutic index. Although pregabalin is effective for treating chronic pain, the clinical use is limited because of its side effects. Therefore, improving its therapeutic index is essential. In this study, HSK16149 was found to be a novel ligand of voltage-gated calcium channel (VGCC) α 2 δ subunit. HSK16149 inhibited [3H]gabapentin binding to the α 2 δ subunit and was 23 times more potent than pregabalin. In two rat models of neuropathic pain, the minimum effective dose (MED) of HSK16149 was 10 mg/kg, and the efficacy was similar to that of 30 mg/kg pregabalin. Moreover, the efficacy of HSK16149 could persist up to 24 hours postadministration at 30 mg/kg, whereas the efficacy of pregabalin lasted only for 12 hours at 30 mg/kg in streptozotocin-induced diabetic neuropathy model, indicating that HSK16149 might be a longer-acting drug candidate. HSK16149 could also inhibit mechanical allodynia in intermittent cold stress model and decrease phase II pain behaviors in formalin-induced nociception model. In addition, the locomotor activity test showed that the MED of HSK16149 was similar to that of pregabalin, whereas in the Rotarod test, the MEDs of HSK16149 and pregabalin were 100 and 30 mg/kg, respectively. These findings indicated that HSK16149 might have a better safety profile on the central nervous system. In summary, HSK16149 is a potent ligand of VGCC α 2 δ subunit with a better therapeutic index than pregabalin. Hence, it could be an effective and safe drug candidate for treating chronic pain. SIGNIFICANCE STATEMENT: As a novel potent ligand of voltage-gated calcium channel α 2 δ subunit, HSK16149 has the potential to be an effective and safe drug candidate for the treatment of chronic pain.
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Affiliation(s)
- Xiaoli Gou
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Xiaojuan Yu
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Dongdong Bai
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Bowei Tan
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Pingfeng Cao
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Meilin Qian
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | | | - Lei Chen
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Zongjun Shi
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Yao Li
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Fei Ye
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Yong Liang
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
| | - Jia Ni
- Haisco Pharmaceutical Group Co., Ltd., Chengdu, China
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9
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Chen HH, Li YD, Cheng PW, Fang YC, Lai CC, Tseng CJ, Pan JY, Yeh TC. Gabapentin Reduces Blood Pressure and Heart Rate through the Nucleus Tractus Solitarii. ACTA CARDIOLOGICA SINICA 2019; 35:627-633. [PMID: 31879515 DOI: 10.6515/acs.201911_35(6).20190429b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Background Oral and intravenous gabapentin can markedly attenuate blood pressure (BP) in hypertensive rats. The nucleus tractus solitarii (NTS) is the primary integrative center for cardiovascular control and other autonomic functions in the central nervous system. However, the signaling mechanisms involved in gabapentin-mediated cardiovascular effects in the NTS remain unclear. We investigated whether the nitric oxide synthase (NOS) signaling pathway was involved in gabapentin-mediated BP regulation in the NTS of spontaneously hypertensive (SHR) rats. Methods SHR rats were anesthetized with urethane at age 10-12 weeks. Arterial pressure and heart rate (HR) were monitored through a femoral artery catheter. For stereotaxic intra-NTS microinjection, the dorsal surface of the medulla was exposed by limited craniotomy. We observed that unilateral microinjection of gabapentin into the NTS whether to change dose-related BP and HR. Then, unilateral microinjection of gabapentin into the NTS before and after N(ω)-nitro-L-arginine methyl ester (L-NAME) treatment whether to change blood pressure and heart rate. Results Unilateral microinjection of gabapentin into the NTS produced prominent dose-related depressor and bradycardic effects in SHR rats. The cardiovascular effects of gabapentin were attenuated by the prior administration of the NOS inhibitor, L-NAME. Conclusions Gabapentin modulated central BP and HR control in the NTS of SHR rats in this study through NOS signaling.
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Affiliation(s)
- Hsin-Hung Chen
- Department of Medical Education and Research.,Yuh-Ing Junior College of Health Care & Management
| | - Yih-Do Li
- Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital
| | - Pei-Wen Cheng
- Department of Medical Education and Research.,Yuh-Ing Junior College of Health Care & Management
| | - Yi-Chien Fang
- Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital
| | | | | | - Jun-Yen Pan
- Division of Cardiovascular Surgery, Department of Surgery.,Department of Nursing, Shu-Zen Junior College of Medicine and Management, Kaohsiung
| | - Tung-Chen Yeh
- Department of Internal Medicine, Division of Cardiology, Kaohsiung Veterans General Hospital.,Department of Nursing, Chung Hwa University of Medical Technology, Tainan, Taiwan
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10
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Martínez San Segundo P, Terni B, Burgueño J, Monroy X, Dordal A, Merlos M, Llobet A. Outside-in regulation of the readily releasable pool of synaptic vesicles by α2δ-1. FASEB J 2019; 34:1362-1377. [PMID: 31914622 DOI: 10.1096/fj.201901551r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/09/2019] [Accepted: 10/23/2019] [Indexed: 12/17/2022]
Abstract
The readily releasable pool (RRP) of synaptic vesicles is a key determinant of phasic neurotransmission. Although the size of the RRP is tightly regulated by intracellular factors, there is little evidence for its modification by extracellular signals. By studying the homogeneous population of synapses present in autaptic microcultures, we show that pregabalin, a prototypical gabapentinoid, decreases the effective RRP size. Simultaneous imaging of presynaptic calcium influx and recording of postsynaptic responses shows that the effect is not related to a reduction of calcium entry. The main cause is the impairment of the functional coupling among N-type calcium channels and the RRP, resembling an increase of intracellular mobile calcium buffers. The ectodomain of neurexin-1α shows a similar action to pregabalin, acting as an endogenous ligand of α2δ-1 that reduces the RRP size without affecting presynaptic calcium influx. The regulatory actions described for pregabalin and the ectodomain of neurexin-1α are mutually exclusive. The overexpression of α2δ-1 enhances the effect of pregabalin and the ectodomain of neurexin-1α on neurotransmission by decreasing their effective concentration. In contrast, knockdown of α2δ-1 causes a profound inhibition of synaptic transmission. These observations prompt to consider α2δ-1 as an outside-in signaling platform that binds exogenous and endogenous cues for regulating the coupling of voltage-gated calcium channels to synaptic vesicles.
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Affiliation(s)
- Pablo Martínez San Segundo
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.,Department of Pathology and Experimental Therapeutics, School of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Beatrice Terni
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.,Department of Pathology and Experimental Therapeutics, School of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
| | - Javier Burgueño
- Department of Pharmacology, Drug Discovery and Preclinical Development, ESTEVE, Barcelona, Spain
| | - Xavier Monroy
- Department of Pharmacology, Drug Discovery and Preclinical Development, ESTEVE, Barcelona, Spain
| | - Albert Dordal
- Department of Pharmacology, Drug Discovery and Preclinical Development, ESTEVE, Barcelona, Spain
| | - Manuel Merlos
- Department of Pharmacology, Drug Discovery and Preclinical Development, ESTEVE, Barcelona, Spain
| | - Artur Llobet
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.,Department of Pathology and Experimental Therapeutics, School of Medicine, Institute of Neurosciences, University of Barcelona, Barcelona, Spain
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11
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Analgesic Potentials of Preoperative Oral Pregabalin, Intravenous Magnesium Sulfate, and their Combination in Acute Postthoracotomy Pain. Clin J Pain 2019; 35:247-251. [DOI: 10.1097/ajp.0000000000000673] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Shimada K, Ohata Y, Kobayashi J, Onishi Y, Kawamura A, Domon Y, Arakawa N, Inoue T, Kitano Y, Matsuda F, Abe Y, Deguchi T. Alkylsulfanyl analogs as potent α 2 δ ligands. Bioorg Med Chem Lett 2018; 28:2000-2002. [DOI: 10.1016/j.bmcl.2018.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/02/2018] [Accepted: 05/03/2018] [Indexed: 10/17/2022]
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13
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Fluyau D, Revadigar N, Manobianco BE. Challenges of the pharmacological management of benzodiazepine withdrawal, dependence, and discontinuation. Ther Adv Psychopharmacol 2018; 8:147-168. [PMID: 29713452 PMCID: PMC5896864 DOI: 10.1177/2045125317753340] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 11/23/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Benzodiazepines (BZDs) are among the most prescribed sedative hypnotics and among the most misused and abused medications by patients, in parallel with opioids. It is estimated that more than 100 million Benzodiazepine (BZD) prescriptions were written in the United States in 2009. While medically useful, BZDs are potentially dangerous. The co-occurring abuse of opioids and BZD, as well as increases in BZD abuse, tolerance, dependence, and short- and long-term side effects, have prompted a worldwide discussion about the challenging aspects of medically managing the discontinuation of BZDs. Abrupt cessation can cause death. This paper addresses the challenges of medications suggested for the management of BZD discontinuation, their efficacy, the risks of abuse and associated medical complications. The focus of this review is on the challenges of several medications suggested for the management of BZD discontinuation, their efficacy, the risks of abuse, and associated medical complications. METHODS An electronic search was performed of Medline, Worldwide Science, Directory of Open Access Journals, Embase, Cochrane Library, Google Scholar, PubMed Central, and PubMed from 1990 to 2017. The review includes double-blind, placebo-controlled studies for the most part, open-label pilot studies, and animal studies, in addition to observational research. We expand the search to review articles, naturalistic studies, and to a lesser extent, letters to the editor/case reports. We exclude abstract and poster presentations, books, and book chapters. RESULTS The efficacy of these medications is not robust. While some of these medicines are relatively safe to use, some of them have a narrow therapeutic index, with severe, life-threatening side effects. Randomized studies have been limited. There is a paucity of comparative research. The review has several limitations. The quality of the documents varies according to whether they are randomized studies, nonrandomized studies, naturalistic studies, pilot studies, letters to the editors, or case reports. CONCLUSIONS The use of medications for the discontinuation of BZDs seems appropriate. It is a challenge that requires further investigation through randomized clinical trials to maximize efficacy and to minimize additional risks and side effects.
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Affiliation(s)
- Dimy Fluyau
- Emory University School of Medicine, 1648 Pierce Dr NE, Atlanta, GA 30307, USA
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14
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Kato AS, Witkin JM. Protein complexes as psychiatric and neurological drug targets. Biochem Pharmacol 2018; 151:263-281. [PMID: 29330067 DOI: 10.1016/j.bcp.2018.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/05/2018] [Indexed: 12/25/2022]
Abstract
The need for improved medications for psychiatric and neurological disorders is clear. Difficulties in finding such drugs demands that all strategic means be utilized for their invention. The discovery of forebrain specific AMPA receptor antagonists, which selectively block the specific combinations of principal and auxiliary subunits present in forebrain regions but spare targets in the cerebellum, was recently disclosed. This discovery raised the possibility that other auxiliary protein systems could be utilized to help identify new medicines. Discussion of the TARP-dependent AMPA receptor antagonists has been presented elsewhere. Here we review the diversity of protein complexes of neurotransmitter receptors in the nervous system to highlight the broad range of protein/protein drug targets. We briefly outline the structural basis of protein complexes as drug targets for G-protein-coupled receptors, voltage-gated ion channels, and ligand-gated ion channels. This review highlights heterodimers, subunit-specific receptor constructions, multiple signaling pathways, and auxiliary proteins with an emphasis on the later. We conclude that the use of auxiliary proteins in chemical compound screening could enhance the detection of specific, targeted drug searches and lead to novel and improved medicines for psychiatric and neurological disorders.
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Affiliation(s)
- Akihiko S Kato
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA.
| | - Jeffrey M Witkin
- Neuroscience Discovery, Lilly Research Labs, Eli Lilly and Company, Indianapolis, IN, USA
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15
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Maher MP, Matta JA, Gu S, Seierstad M, Bredt DS. Getting a Handle on Neuropharmacology by Targeting Receptor-Associated Proteins. Neuron 2017; 96:989-1001. [PMID: 29216460 DOI: 10.1016/j.neuron.2017.10.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 12/13/2022]
Abstract
Targeted therapy for neuropsychiatric disorders requires selective modulation of dysfunctional neuronal pathways. Receptors relevant to CNS disorders typically have associated proteins discretely expressed in specific neuronal pathways; these accessory proteins provide a new dimension for drug discovery. Recent studies show that targeting a TARP auxiliary subunit of AMPA receptors selectively modulates neuronal excitability in specific forebrain pathways relevant to epilepsy. Other medicinally important ion channels, gated by glutamate, γ-aminobutyric acid (GABA), and acetylcholine, also have associated proteins, which may be druggable. This emerging pharmacology of receptor-associated proteins provides a new approach for improving drug efficacy while mitigating side effects.
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Affiliation(s)
- Michael P Maher
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Jose A Matta
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Shenyan Gu
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - Mark Seierstad
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA
| | - David S Bredt
- Neuroscience Discovery, Janssen Pharmaceutical Companies of Johnson & Johnson, 3210 Merryfield Row, San Diego, CA 92121, USA.
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16
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Ahmad N, Subhan F, Islam NU, Shahid M, Rahman FU, Sewell RD. Gabapentin and its salicylaldehyde derivative alleviate allodynia and hypoalgesia in a cisplatin-induced neuropathic pain model. Eur J Pharmacol 2017; 814:302-312. [DOI: 10.1016/j.ejphar.2017.08.040] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/03/2017] [Accepted: 08/24/2017] [Indexed: 12/15/2022]
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17
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Smith RV, Havens JR, Walsh SL. Gabapentin misuse, abuse and diversion: a systematic review. Addiction 2016; 111:1160-74. [PMID: 27265421 PMCID: PMC5573873 DOI: 10.1111/add.13324] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/24/2015] [Accepted: 01/20/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Since its market release, gabapentin has been presumed to have no abuse potential and subsequently has been prescribed widely off-label, despite increasing reports of gabapentin misuse. This review estimates and describes the prevalence and effects of, motivations behind and risk factors for gabapentin misuse, abuse and diversion. METHODS Databases were searched for peer-reviewed papers demonstrating gabapentin misuse, characterized by taking a larger dosage than prescribed or taking gabapentin without a prescription, and diversion. All types of studies were considered; grey literature was excluded. Thirty-three papers met inclusion criteria, consisting of 23 case studies and 11 epidemiological reports. Published reports came from the United States, the United Kingdom, Germany, Finland, India, South Africa and France, and two analyzed websites not specific to a particular country. RESULTS Prevalence of gabapentin misuse in the general population was reported to be 1%, 40-65% among individuals with prescriptions and between 15 and 22% within populations of people who abuse opioids. An array of subjective experiences reminiscent of opioids, benzodiazepines and psychedelics were reported over a range of doses, including those within clinical recommendations. Gabapentin was misused primarily for recreational purposes, self-medication or intentional self-harm and was misused alone or in combination with other substances, especially opioids, benzodiazepines and/or alcohol. Individuals with histories of drug abuse were most often involved in its misuse. CONCLUSIONS Epidemiological and case report evidence suggests that the anti-epileptic and analgesic medication gabapentin is being misused internationally, with substance abuse populations at special risk for misuse/abuse.
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Affiliation(s)
- Rachel V. Smith
- Center on Drug and Alcohol Research, Department of Behavioral
Science, University of Kentucky College of Medicine, Lexington, KY,Department of Epidemiology, University of Kentucky College of Public
Health, Lexington, KY,Department of Biostatistics, University of Kentucky College of
Public Health, Lexington, KY
| | - Jennifer R. Havens
- Center on Drug and Alcohol Research, Department of Behavioral
Science, University of Kentucky College of Medicine, Lexington, KY,Department of Epidemiology, University of Kentucky College of Public
Health, Lexington, KY
| | - Sharon L. Walsh
- Center on Drug and Alcohol Research, Department of Behavioral
Science, University of Kentucky College of Medicine, Lexington, KY,Department of Pharmacology, University of Kentucky College of
Medicine, Lexington, KY,Department of Pharmaceutical Sciences, University of Kentucky
College of Pharmacy, Lexington, KY,Corresponding Author: Sharon L. Walsh, PhD, Center on
Drug and Alcohol Research, Department of Behavioral Science, University of
Kentucky College of Medicine, 845 Angliana Avenue, Lexington, KY 40508, Phone:
859-257-6485,
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18
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Offord J, Isom LL. Drugging the undruggable: gabapentin, pregabalin and the calcium channel α2δ subunit. Crit Rev Biochem Mol Biol 2016; 51:246-56. [DOI: 10.3109/10409238.2016.1173010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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19
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Hiranita T. (-)-Trans-Δ 9-Tetrahydrocannabinol-Like Discriminative-Stimulus Effects of Gabapentin in Cannabis Users. ACTA ACUST UNITED AC 2016; 4. [PMID: 27376100 DOI: 10.4172/2329-6488.1000e129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Takato Hiranita
- Division of Neurotoxicology, National Center for Toxicological Research (NCTR), U.S. Food and Drug Administration (FDA), USA
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20
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Ostadhadi S, Kordjazy N, Haj-Mirzaian A, Ameli S, Akhlaghipour G, Dehpour A. Involvement of NO/cGMP pathway in the antidepressant-like effect of gabapentin in mouse forced swimming test. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:393-402. [PMID: 26753696 DOI: 10.1007/s00210-015-1203-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 12/21/2015] [Indexed: 12/24/2022]
Abstract
Based on clinical studies regarding the beneficial effect of gabapentin in depression, we aimed to evaluate the antidepressant-like properties of gabapentin in mice and also the participation of nitric oxide (NO)/cyclic guanosine monophosphate pathway in this effect. The following drugs were used in this study: gabapentin; N(G)-nitro-L-arginine methyl ester (L-NAME), a non-specific NO synthase (NOS) inhibitor; 7-nitroindazole, a specific neuronal NOS inhibitor; aminoguanidine, a specific inducible NOS inhibitor; L-arginine, a NO precursor; and sildenafil, a phosphodiestrase inhibitor. Finally, we studied the behavioral effects through the forced swimming test (FST) and the changes of the hippocampus NO level through nitrite assay. The immobility time was significantly reduced after gabapentin administration. Co-administration of non-effective doses of gabapentin and L-NAME or 7-nitroindazole (7-NI) resulted in antidepressant-like effect in FST, while aminoguanidine did not affect the immobility time of gabapentin-treated mice. Furthermore, the antidepressant-like property of gabapentin was prevented by L-arginine or sildenafil. Also, the hippocampal nitrite level was significantly lower in gabapentin-treated mice relative to saline-injected mice, and co-administration of 7-NI with sub-effective gabapentin caused a significant decrease in hippocampal nitrite levels. Our results indicate that the antidepressant-like effect of gabapentin in the mice FST model is mediated at least in part through nitric oxide/cyclic guanosine monophosphate (cGMP) pathway.
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Affiliation(s)
- Sattar Ostadhadi
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Nastaran Kordjazy
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Arya Haj-Mirzaian
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sanaz Ameli
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Golnoosh Akhlaghipour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - AhmadReza Dehpour
- Experimental Medicine Research Center, Tehran University of Medical Sciences, Tehran, Iran.
- Brain and Spinal Cord Injury Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran.
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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21
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Zvejniece L, Vavers E, Svalbe B, Veinberg G, Rizhanova K, Liepins V, Kalvinsh I, Dambrova M. R-phenibut binds to the α2-δ subunit of voltage-dependent calcium channels and exerts gabapentin-like anti-nociceptive effects. Pharmacol Biochem Behav 2015; 137:23-9. [PMID: 26234470 DOI: 10.1016/j.pbb.2015.07.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 07/26/2015] [Accepted: 07/29/2015] [Indexed: 02/02/2023]
Abstract
Phenibut is clinically used anxiolytic, mood elevator and nootropic drug. R-phenibut is responsible for the pharmacological activity of racemic phenibut, and this activity correlates with its binding affinity for GABAB receptors. In contrast, S-phenibut does not bind to GABAB receptors. In this study, we assessed the binding affinities of R-phenibut, S-phenibut, baclofen and gabapentin (GBP) for the α2-δ subunit of the voltage-dependent calcium channel (VDCC) using a subunit-selective ligand, radiolabelled GBP. Binding experiments using rat brain membrane preparations revealed that the equilibrium dissociation constants (Kis) for R-phenibut, S-phenibut, baclofen and GBP were 23, 39, 156 and 0.05μM, respectively. In the pentylenetetrazole (PTZ)-induced seizure test, we found that at doses up to 100mg/kg, R-phenibut did not affect PTZ-induced seizures. The anti-nociceptive effects of R-phenibut were assessed using the formalin-induced paw-licking test and the chronic constriction injury (CCI) of the sciatic nerve model. Pre-treatment with R-phenibut dose-dependently decreased the nociceptive response during both phases of the test. The anti-nociceptive effects of R-phenibut in the formalin-induced paw-licking test were not blocked by the GABAB receptor-selective antagonist CGP35348. In addition, treatment with R- and S-phenibut alleviated the mechanical and thermal allodynia induced by CCI of the sciatic nerve. Our data suggest that the binding affinity of R-phenibut for the α2-δ subunit of the VDCC is 4 times higher than its affinity for the GABAB receptor. The anti-nociceptive effects of R-phenibut observed in the tests of formalin-induced paw licking and CCI of the sciatic nerve were associated with its effect on the α2-δ subunit of the VDCC rather than with its effects on GABAB receptors. In conclusion, our results provide experimental evidence for GBP-like, anti-nociceptive properties of R-phenibut, which might be used clinically to treat neuropathic pain disorders.
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Affiliation(s)
- Liga Zvejniece
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia.
| | - Edijs Vavers
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia; Riga Stradins University, Dzirciema 16, Riga, LV-1007, Latvia
| | - Baiba Svalbe
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Grigory Veinberg
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | | | | | - Ivars Kalvinsh
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Maija Dambrova
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia; Riga Stradins University, Dzirciema 16, Riga, LV-1007, Latvia
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22
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Abstract
The α2δ auxiliary subunits of voltage-gated Ca2+ channels (VGCCs) are important modulators of VGCC function. Gabapentin interacts with α2δ1 and α2δ2 subunits and is reported to reduce Ca2+ channel current amplitude (ICa). This study aimed to determine the effects of gabapentin on VGCCs in retinal ganglion cells (RGCs). Whole cell patch clamp was used to record ICa in isolated RGCs, and calcium imaging was used to measure Ca2+ transients from RGCs in situ. Immunohistochemistry was used to detect the presence of α2δ1-containing VGCCs in isolated RGCs in the absence and presence of gabapentin pretreatment. Acute administration of gabapentin reduced ICa and Ca2+ transients compared to control conditions. In isolated RGCs, pretreatment with gabapentin (4-18 h) reduced ICa, and cell surface α2δ1 staining was reduced compared to nonpretreated cells. Acute administration of gabapentin to isolated RGCs that had been pretreated further reduced ICa. These results show that gabapentin has both short-term and long-term mechanisms to reduce ICa in isolated RGCs. Some Ca2+ channel blockers have been shown to protect RGCs in retinal trauma suggesting that modulation of VGCCs by gabapentin may prevent the deleterious effects of elevated Ca2+ levels in RGCs in trauma and disease.
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23
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Arranz-Tagarro JA, de los Ríos C, García AG, Padín JF. Recent patents on calcium channel blockers: emphasis on CNS diseases. Expert Opin Ther Pat 2014; 24:959-77. [DOI: 10.1517/13543776.2014.940892] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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24
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Fukasawa H, Muratake H, Ito A, Suzuki H, Amano Y, Nagae M, Sugiyama K, Shudo K. Silicon-containing GABA derivatives, silagaba compounds, as orally effective agents for treating neuropathic pain without central-nervous-system-related side effects. ACS Chem Neurosci 2014; 5:525-32. [PMID: 24738473 PMCID: PMC4102965 DOI: 10.1021/cn500053d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Neuropathic pain is a chronic condition resulting from neuronal damage. Pregabalin, the (S)-isomer of 3-isobutyl-γ-aminobutyric acid (GABA), is widely used to treat neuropathic pain, despite the occurrence of central nervous system (CNS)-related side effects such as dizziness and somnolence. Here we describe the pharmacology of novel GABA derivatives containing silicon-carbon bonds, silagaba compounds. Silagaba131, 132, and 161 showed pregabalin-like analgesic activities in animal models of neuropathic pain, but in contrast to pregabalin they did not impair neuromuscular coordination in rotarod tests. Pharmacokinetic studies showed that brain exposure to silagaba compounds was lower than that to pregabalin. Surprisingly, despite their potent analgesic action in vivo, silagaba compounds showed only weak binding to α2-δ protein. These compounds may be useful to study mechanisms of neuropathic pain. Our results also indicate that silagaba132 and 161 are candidates for orally effective treatment of neuropathic pain without CNS-related side effects.
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Affiliation(s)
- Hiroshi Fukasawa
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
| | - Hideaki Muratake
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
| | - Ai Ito
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
| | - Hideyuki Suzuki
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
| | - Yohei Amano
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
| | - Marina Nagae
- Department
of Clinical Pharmacokinetics, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Kiyoshi Sugiyama
- Department
of Clinical Pharmacokinetics, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Koichi Shudo
- Research Foundation
ITSUU Laboratory, 2-28-10 Tamagawa, Setagaya-ku, Tokyo 158-0094, Japan
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25
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Pregabalin rectifies aberrant brain chemistry, connectivity, and functional response in chronic pain patients. Anesthesiology 2014; 119:1453-64. [PMID: 24343290 DOI: 10.1097/aln.0000000000000017] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Chronic pain remains a significant challenge for modern health care as its pathologic mechanisms are largely unknown and preclinical animal models suffer from limitations in assessing this complex subjective experience. However, human brain neuroimaging techniques enable the assessment of functional and neurochemical alterations in patients experiencing chronic pain and how these factors may dynamically change with pharmacologic treatment. METHODS To identify the clinical action of pregabalin, a proven analgesic, the authors performed three complementary brain neuroimaging procedures: (proton magnetic resonance spectroscopy, functional magnetic resonance imaging, and functional connectivity magnetic resonance imaging) in 17 chronic pain patients diagnosed with fibromyalgia. RESULTS The authors found that pregabalin but not placebo reduces combined glutamate + glutamine levels within the posterior insula (pregabalin P = 0.016; placebo P = 0.71). Interestingly, reductions in clinical pain were associated with reductions in brain connectivity of this structure to brain regions within the default mode network during pregabalin (r = 0.82; P = 0.001) but not placebo (r = -0.13; P = 0.63). Response of default mode network regions to experimental pain was also reduced with pregabalin (P = 0.018) but not placebo (P = 0.182). Perhaps most importantly, baseline values for all three neuroimaging markers predicted subsequent analgesic response to pregabalin but not placebo. CONCLUSIONS The results of this study suggest that pregabalin works in part by reducing insular glutamatergic activity, leading to a reduction of the increased functional connectivity seen between brain regions in chronic pain states. The study also supports a role for human brain imaging in the development, assessment, and personalized use of central-acting analgesics.
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Yildirim K, Şışecıoğlu M, Karatay S, Erdal A, Levent A, Uğur M, Şenel K. The effectiveness of gabapentin in patients with chronic radiculopathy. ACTA ACUST UNITED AC 2013. [DOI: 10.1163/156856903767650718] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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27
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Schuwald AM, Nöldner M, Wilmes T, Klugbauer N, Leuner K, Müller WE. Lavender oil-potent anxiolytic properties via modulating voltage dependent calcium channels. PLoS One 2013; 8:e59998. [PMID: 23637742 PMCID: PMC3639265 DOI: 10.1371/journal.pone.0059998] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 02/21/2013] [Indexed: 01/28/2023] Open
Abstract
Recent clinical data support the clinical use of oral lavender oil in patients suffering from subsyndromal anxiety. We identified the molecular mechanism of action that will alter the perception of lavender oil as a nonspecific ingredient of aromatherapy to a potent anxiolytic inhibiting voltage dependent calcium channels (VOCCs) as highly selective drug target. In contrast to previous publications where exorbitant high concentrations were used, the effects of lavender oil in behavioral, biochemical, and electrophysiological experiments were investigated in physiological concentrations in the nanomolar range, which correlate to a single dosage of 80 mg/d in humans that was used in clinical trials. We show for the first time that lavender oil bears some similarities with the established anxiolytic pregabalin. Lavender oil inhibits VOCCs in synaptosomes, primary hippocampal neurons and stably overexpressing cell lines in the same range such as pregabalin. Interestingly, Silexan does not primarily bind to P/Q type calcium channels such as pregabalin and does not interact with the binding site of pregabalin, the α2δ subunit of VOCCs. Lavender oil reduces non-selectively the calcium influx through several different types of VOCCs such as the N-type, P/Q-type and T-type VOCCs. In the hippocampus, one brain region important for anxiety disorders, we show that inhibition by lavender oil is mainly mediated via N-type and P/Q-type VOCCs. Taken together, we provide a pharmacological and molecular rationale for the clinical use of the oral application of lavender oil in patients suffering from anxiety.
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Affiliation(s)
- Anita M. Schuwald
- Department of Pharmacology, Biocenter, Goethe University, Frankfurt, Germany
| | | | - Thomas Wilmes
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs Universität, Freiburg, Germany
| | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs Universität, Freiburg, Germany
| | - Kristina Leuner
- Department of Molecular and Clinical Pharmacy, Friedrich-Alexander University, Erlangen, Germany
- * E-mail:
| | - Walter E. Müller
- Department of Pharmacology, Biocenter, Goethe University, Frankfurt, Germany
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28
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Banote RK, Koutarapu S, Chennubhotla KS, Chatti K, Kulkarni P. Oral gabapentin suppresses pentylenetetrazole-induced seizure-like behavior and cephalic field potential in adult zebrafish. Epilepsy Behav 2013; 27:212-9. [PMID: 23466252 DOI: 10.1016/j.yebeh.2013.01.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/28/2012] [Accepted: 01/29/2013] [Indexed: 12/20/2022]
Abstract
We report the effect of orally administered gabapentin (GBP) on pentylenetetrazole (PTZ)-induced seizure-like activity in adult zebrafish. Zebrafish were pretreated with vehicle or GBP using a novel method of precise oral administration, followed by an intraperitoneal administration of PTZ. Behavioral assessment was carried out using locomotion-based video-tracking analysis and seizure score assignment using visual observation. Cephalic field potential recordings of the zebrafish brain were conducted using an electrical data acquisition system. Orally administered GBP significantly suppressed the seizure-like locomotor activity and strong slow-wave (~3Hz) activity in the cephalic field potential caused by PTZ. This work is the first report of the activity of an orally delivered anticonvulsant in adult zebrafish. Our study provides behavioral and physiological evidence in support of an adult zebrafish model for studying seizures including excitotoxic brain injury and a novel in vivo framework for the evaluation of pharmacological modulators of epilepsy.
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Affiliation(s)
- Rakesh Kumar Banote
- Dr Reddy's Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500046, India
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29
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Abstract
P/Q-type calcium channels are high-voltage-gated calcium channels contributing to vesicle release at synaptic terminals. A number of neurological diseases have been attributed to malfunctioning of P/Q channels, including ataxia, migraine and Alzheimer's disease. To date, only two specific P/Q-type blockers are known: both are peptides deriving from the spider venom of Agelenopsis aperta, ω-agatoxins. Other peptidic calcium channel blockers with activity at P/Q channels are available, albeit with less selectivity. A number of low molecular weight compounds modulate P/Q-type currents with different characteristics, and some exhibit a peculiar bidirectional pattern of modulation. Interestingly, there are a number of therapeutics in clinical use, which also show P/Q channel activity. Because selectivity as well as the exact mode of action is different between all P/Q-type channel modulators, the interpretation of clinical and experimental data is complicated and needs a comprehensive understanding of their target profile. The situation is further complicated by the fact that information on potency varies vastly in the literature, which may be the result of different experimental systems, conditions or the splice variants of the P/Q channel. This review attempts to provide a comprehensive overview of the compounds available that affect the P/Q-type channel and should help with the interpretation of results of in vitro experiments and animal models. It also aims to explain some clinical observations by implementing current knowledge about P/Q channel modulation of therapeutically used non-selective drugs. Chances and challenges of the development of P/Q channel-selective molecules are discussed.
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Affiliation(s)
- V Nimmrich
- Neuroscience Research, GPRD, Abbott, Ludwigshafen, Germany
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31
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O' Mahony SM, Coelho AM, Fitzgerald P, Lee K, Winchester W, Dinan TG, Cryan JF. The effects of gabapentin in two animal models of co-morbid anxiety and visceral hypersensitivity. Eur J Pharmacol 2011; 667:169-74. [PMID: 21645509 DOI: 10.1016/j.ejphar.2011.05.055] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 05/18/2011] [Accepted: 05/22/2011] [Indexed: 11/18/2022]
Abstract
Visceral hypersensitivity and an increased response to stress are two of the main symptoms of irritable bowel syndrome. Thus efforts to develop animal models of irritable bowel syndrome have centred on both of these parameters. The anticonvulsant gabapentin, which is widely used as an analgesic agent, also reduces anxiety. No data exists to our knowledge of the effects of gabapentin in animal models of co-morbid exaggerated stress response and visceral pain. Our aim was to assess the effect of gabapentin on stress and visceral hypersensitivity in two different animal models of irritable bowel syndrome. The animal models employed were the genetically susceptible Wistar Kyoto rat and the neonatally stressed maternal separation model. These animals were subjected to the open field paradigm to assess stress-induced defecation rates and colorectal distension to assess the level of visceral sensitivity. Gabapentin (30 mg/kg) prevented the stress-induced increase in faecal pellet output in the maternally separated rat, but not the Wistar Kyoto animals. On the other hand gabapentin (30 mg/kg) reduced the number of pain behaviours in response to colorectal distension in both models. These results show that whilst both models have similar responses to gabapentin in terms of visceral pain they differ in terms of their physiological response to stress. This indicates that the origin of anxiety and perhaps then visceral hypersensitivity differs in these models. Overall, these data suggest that gabapentin may be a useful treatment in disorders of co-morbid pain and an overactive stress system such as irritable bowel syndrome.
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Affiliation(s)
- Siobhain M O' Mahony
- Laboratory of Neurogastroenterology, Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
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32
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Tsukumo Y, Matsumoto Y, Miura H, Yano H, Manabe H. Gabapentin and pregabalin inhibit the itch-associated response induced by the repeated application of oxazolone in mice. J Pharmacol Sci 2010; 115:27-35. [PMID: 21157120 DOI: 10.1254/jphs.10173fp] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We investigated the effects of gabapentin and pregabalin on the itch-associated response in a mouse model of chronic dermatitis induced by the repeated application of 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone). Challenging the mice with oxazolone-induced chronic dermatitis with the oxazolone evoked severe and transient scratching behavior until 1 h after the application of oxazolone. Thereafter, a more mild and continuous scratching behavior was also observed for at least 8 h. Both severe and continuous scratching behaviors were suppressed by systemic injection of gabapentin and pregabalin. This effect of these compounds was correlated with its affinity for the α₂δ subunit of voltage-gated Ca²(+) channels. Intrathecal injection, but not peripheral treatment, with gabapentin inhibited the scratching behavior in this model. Gabapentin failed to suppress the scratching behavior induced by the intradermal injection of compound 48/80 in normal mice. The expression of the α₂δ-1 subunit in dorsal root ganglion (DRG) from mice following repeated application of oxazolone was significantly higher than that from normal mice. These results suggest that gabapentin and pregabalin show an anti-pruritic activity through α₂δ-subunit binding, and the up-regulation of the α₂δ-1 subunit in DRG may therefore play an important role in its anti-pruritic activity.
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33
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Gerlach AC, Krajewski JL. Antiepileptic Drug Discovery and Development: What Have We Learned and Where Are We Going? Pharmaceuticals (Basel) 2010; 3:2884-2899. [PMID: 27713381 PMCID: PMC4034102 DOI: 10.3390/ph3092884] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 08/25/2010] [Accepted: 09/01/2010] [Indexed: 11/16/2022] Open
Abstract
Current marketed antiepileptic drugs (AEDs) consist of a variety of structural classes with different mechanisms of action. These agents typically have non-overlapping efficacy and side-effect profiles presenting multiple treatment options for the patient population. However, approximately 30% of seizure sufferers fail to respond to current therapies often because poorly tolerated side-effects limit adequate dosing. The scope of this review is to summarize selected advances in 2nd and 3rd generation AEDs as well as compounds in development with novel mechanisms of action.
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34
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Ochi Y, Harada T, Kikuchi C, Arakawa A. [Pharmacology profile and clinical findings of pregabalin (Lyrica capsule)]. Nihon Yakurigaku Zasshi 2010; 136:165-174. [PMID: 20838020 DOI: 10.1254/fpj.136.165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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35
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Abstract
No single analgesic drug provides the perfect therapeutic/adverse effect profile for every pain condition. In addition to convenience and possibly improved compliance, a combination of analgesic drugs offers the potential, requiring verification, of providing greater pain relief and/or reduced adverse effects than the constituent drugs when used individually. We review here analgesic combinations containing oxycodone. We found surprisingly little preclinical information about the analgesic or adverse effect profiles of the combinations (with acetaminophen, paracetamol, nonsteroidal anti-inflammatory drugs, morphine, gabapentin or pregabalin). Clinical experience and studies suggest that the combinations are safe and effective and may offer certain advantages. As with all combinations, the profile of adverse effects must also be determined in order to provide the clinician with the overall benefit/risk assessment.
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Affiliation(s)
- R B Raffa
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania, USA.
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36
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Agarwal P, Griffith A, Costantino HR, Vaish N. Gabapentin enacarbil - clinical efficacy in restless legs syndrome. Neuropsychiatr Dis Treat 2010; 6:151-8. [PMID: 20505847 PMCID: PMC2874339 DOI: 10.2147/ndt.s5712] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Restless legs syndrome (RLS) is a sleep-related movement disorder commonly involving an unpleasant urge to move the limbs, typically the legs. Dopaminergic agents represent the first-line therapy for RLS; however, long-term use of such drugs results in worsening symptoms due to "augmentation" or other adverse events. Gabapentin, an analog of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), is an anticonvulsant/analgesic agent. Gabapentin is only mildly effective in relieving RLS symptoms, perhaps a result of its poor absorption from the gastrointestinal (GI) tract. Gabapentin enacarbil is a prodrug of gabapentin specifically designed to enhance absorption via the GI tract, and hence provide improved circulating levels of gabapentin on metabolism. Clinical trials to date have demonstrated favorable safety and (compared to traditional gabapentin) improved pharmacokinetics and efficacy in treating RLS symptoms. Thus, gabapentin enacarbil may prove to be a useful drug in treating RLS. An application of gabapentin enacarbil for treatment of RLS is currently pending with FDA for approval.
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37
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Cuellar-Herrera M, Peña F, Alcantara-Gonzalez D, Neri-Bazan L, Rocha L. Antiepileptic drugs combined with high-frequency electrical stimulation in the ventral hippocampus modify pilocarpine-induced status epilepticus in rats. Epilepsia 2010; 51:432-7. [DOI: 10.1111/j.1528-1167.2009.02315.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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38
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Cheng FC, Feng JJ, Chen KH, Imanishi H, Fujishima M, Takekoshi H, Naoki Y, Shimoda M. Receptor binding activities of Chlorella on cysteinyl leukotriene CysLT, glutamate AMPA, ion channels, purinergic P 2Y, tachykinin NK2 receptors and adenosine transporter. Phytother Res 2010; 24:43-8. [PMID: 19517465 DOI: 10.1002/ptr.2864] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A Chlorella powder was tested in a total of 129 in vitro receptor binding assay systems. The results showed a potent inhibition of this powder on cysteinyl leukotriene CysLT2, and glutamate AMPA in a dose-concentration manner with IC(50) mean +/- SEM values of 20 +/- 4.5 microg/mL and 44 +/- 14 microg/mL, respectively. Other moderate and weak activities reflected in competitive binding experiments were seen versus adenosine transporter; calcium channel L-type, benzothiazepine; gabapentin; kainate, NMDA-glycine; inositol trisphosphate IP(3); cysteinyl CysLT(1), LTB(4); purinergic P(2Y); tachykinin NK(2); serotonin 5-HT(2B) and prostanoid, thromboxane A(2). Together, the results suggest that the various inhibitory effects of Chlorella powder in these receptor binding assays could reflect its actions in modulating Ca(2+)-dependent signal related targets and might be relevant to the mechanisms of its biological effects. These results reveal important potential biochemical activities that might be exploited for the prevention or treatment of several pathologies. From these results, the possible therapeutic usage of the product is discussed.
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Affiliation(s)
- Fong-Chi Cheng
- MDS Pharma Services Taiwan Ltd, 158 Li-Teh Road, Peitou, Taipei, 112, Taiwan, ROC.
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39
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Eroglu C, Allen NJ, Susman MW, O'Rourke NA, Park CY, Ozkan E, Chakraborty C, Mulinyawe SB, Annis DS, Huberman AD, Green EM, Lawler J, Dolmetsch R, Garcia KC, Smith SJ, Luo ZD, Rosenthal A, Mosher DF, Barres BA. Gabapentin receptor alpha2delta-1 is a neuronal thrombospondin receptor responsible for excitatory CNS synaptogenesis. Cell 2009; 139:380-92. [PMID: 19818485 PMCID: PMC2791798 DOI: 10.1016/j.cell.2009.09.025] [Citation(s) in RCA: 648] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2008] [Revised: 02/04/2009] [Accepted: 08/26/2009] [Indexed: 11/29/2022]
Abstract
Synapses are asymmetric cellular adhesions that are critical for nervous system development and function, but the mechanisms that induce their formation are not well understood. We have previously identified thrombospondin as an astrocyte-secreted protein that promotes central nervous system (CNS) synaptogenesis. Here, we identify the neuronal thrombospondin receptor involved in CNS synapse formation as alpha2delta-1, the receptor for the anti-epileptic and analgesic drug gabapentin. We show that the VWF-A domain of alpha2delta-1 interacts with the epidermal growth factor-like repeats common to all thrombospondins. alpha2delta-1 overexpression increases synaptogenesis in vitro and in vivo and is required postsynaptically for thrombospondin- and astrocyte-induced synapse formation in vitro. Gabapentin antagonizes thrombospondin binding to alpha2delta-1 and powerfully inhibits excitatory synapse formation in vitro and in vivo. These findings identify alpha2delta-1 as a receptor involved in excitatory synapse formation and suggest that gabapentin may function therapeutically by blocking new synapse formation.
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Affiliation(s)
- Cagla Eroglu
- Duke University Medical Center, Cell Biology Department, Durham, NC 27710, USA.
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40
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Chiechio S, Zammataro M, Caraci F, Rampello L, Copani A, Sabato AF, Nicoletti F. Pregabalin in the treatment of chronic pain: an overview. Clin Drug Investig 2009; 29:203-13. [PMID: 19243212 DOI: 10.2165/00044011-200929030-00006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Chronic 'pathological' pain is sustained by mechanisms of peripheral and central sensitization, which are being increasingly investigated at the molecular and cellular levels. The molecular determinants of nociceptive sensitization are natural targets for potential analgesic drugs used in the treatment of different forms of pain. Most of these determinants are common to all forms of chronic pain, and it is therefore not surprising that drugs specifically targeted for the treatment of neuropathic pain are effective in relieving nociceptive inflammatory pain and vice versa. The molecular mechanisms of sensitization that occur in peripheral nociceptors and the dorsal horns of the spinal cord are putative targets for context-dependent drugs, i.e. drugs that are able to discriminate between 'normal' and 'pathological' pain transmission. Among these, pregabalin and gabapentin bind to the alpha(2)delta subunit of voltage-sensitive Ca2+ channels, which sustain the enhanced release of pain transmitters at the synapses between primary afferent fibres and second-order sensory neurons under conditions of chronic pain. Pregabalin in particular represents a remarkable example of a context-dependent analgesic drug that acts at a critical step of nociceptive sensitization. Preclinical and clinical data suggest that pregabalin is more than a structural and functional analogue of gabapentin and may be effective in the treatment of nociceptive inflammatory pain that is resistant to gabapentin.
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Affiliation(s)
- S Chiechio
- Department of Pharmaceutical Sciences, University of Catania, Catania, Italy
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41
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Rogawski MA, Bazil CW. New molecular targets for antiepileptic drugs: alpha(2)delta, SV2A, and K(v)7/KCNQ/M potassium channels. Curr Neurol Neurosci Rep 2008; 8:345-52. [PMID: 18590620 DOI: 10.1007/s11910-008-0053-7] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Many currently prescribed antiepileptic drugs (AEDs) act via voltage-gated sodium channels, through effects on gamma-aminobutyric acid-mediated inhibition, or via voltage-gated calcium channels. Some newer AEDs do not act via these traditional mechanisms. The molecular targets for several of these nontraditional AEDs have been defined using cellular electrophysiology and molecular approaches. Here, we describe three of these targets: alpha(2)delta, auxiliary subunits of voltage-gated calcium channels through which the gabapentinoids gabapentin and pregabalin exert their anticonvulsant and analgesic actions; SV2A, a ubiquitous synaptic vesicle glycoprotein that may prepare vesicles for fusion and serves as the target for levetiracetam and its analog brivaracetam (which is currently in late-stage clinical development); and K(v)7/KCNQ/M potassium channels that mediate the M-current, which acts a brake on repetitive firing and burst generation and serves as the target for the investigational AEDs retigabine and ICA-105665. Functionally, all of the new targets modulate neurotransmitter output at synapses, focusing attention on presynaptic terminals as critical sites of action for AEDs.
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Affiliation(s)
- Michael A Rogawski
- Department of Neurology, School of Medicine, University of California, Davis, 4860 Y Street, Suite 3700, Sacramento, CA 95817, USA.
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42
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Siok CJ, Taylor CP, Hajós M. Anxiolytic profile of pregabalin on elicited hippocampal theta oscillation. Neuropharmacology 2008; 56:379-85. [PMID: 18930748 DOI: 10.1016/j.neuropharm.2008.09.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Revised: 09/02/2008] [Accepted: 09/10/2008] [Indexed: 11/27/2022]
Abstract
Previous published work with the novel anticonvulsant, analgesic and anti-anxiety medication, pregabalin (Lyrica), has shown that it has anxiolytic-like actions in several animal behavioral models. However, pregabalin is structurally and pharmacologically different from other classes of known anxiolytic drugs, and the mechanisms that alter brain activity to produce anxiolytic-like actions are not well understood. In an effort to determine more about the cellular mechanisms of pregabalin, we studied its effects on hippocampal theta activity of urethane-anesthetized rats that was elicited by electrical stimulation of the nucleus pontis oralis (nPO) in the brainstem. We found that systemic administration of pregabalin significantly reduced the frequency of stimulation-induced hippocampal theta activity similarly to the effects of diazepam. In addition, pregabalin (but not diazepam) significantly altered the stimulus intensity/frequency relationship, and increased slow delta oscillation (<3.0Hz) in spontaneous hippocampal EEG in a dose-dependent manner. Our findings suggest that pregabalin may alter evoked theta frequency activity in the hippocampus by reducing neurotransmitter-mediated activation of either the septal nucleus or the hippocampus, and that its actions are unlikely to be mediated by direct activation of GABA neurotransmitter systems. These observations provide further insight to the action of pregabalin, and support the utilization of stimulation-induced theta model in discovery of novel anxiolytic drugs.
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Affiliation(s)
- Chester J Siok
- Department of Neuroscience, Pfizer Global Research and Development, Eastern Point Road, Groton, CT 06340, USA
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43
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Peng XQ, Li X, Li J, Ramachandran PV, Gagare PD, Pratihar D, Ashby CR, Gardner EL, Xi ZX. Effects of gabapentin on cocaine self-administration, cocaine-triggered relapse and cocaine-enhanced nucleus accumbens dopamine in rats. Drug Alcohol Depend 2008; 97:207-15. [PMID: 18065162 PMCID: PMC2574799 DOI: 10.1016/j.drugalcdep.2007.09.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Revised: 07/31/2007] [Accepted: 09/12/2007] [Indexed: 10/22/2022]
Abstract
Gabapentin is a gamma-aminobutyric acid (GABA) analogue, with GABAmimetic pharmacological properties. Gabapentin is used for the treatment of seizures, anxiety and neuropathic pain. It has been proposed that gabapentin may be useful in the treatment of cocaine dependence. However, clinical trials with gabapentin have shown conflicting results, while preclinical studies are sparse. In the present study, we investigated the effects of gabapentin on intravenous cocaine self-administration and cocaine-triggered reinstatement of drug-seeking behavior, as well as on cocaine-enhanced dopamine (DA) in the nucleus accumbens (NAc). We found that gabapentin (25-200 mg/kg, i.p., 30 min or 2 h prior to cocaine) failed to inhibit intravenous cocaine (0.5 mg/kg/infusion) self-administration under a fixed-ratio reinforcement schedule or cocaine-triggered reinstatement of cocaine-seeking behavior. In vivo microdialysis showed that the same doses of gabapentin produced a modest increase (approximately 50%, p<0.05) in extracellular NAc GABA levels, but failed to alter either basal or cocaine-enhanced NAc DA. These data suggest that gabapentin is a weak GABA-mimic drug. At the doses tested, it has no effect in the addiction-related animal behavioral models here tested. This is in striking contrast to positive findings in the same animal models shown by another GABAmimetic--gamma-vinyl GABA (see companion piece to present article).
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Affiliation(s)
- Xiao-Qing Peng
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - Xia Li
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - Jie Li
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - P. Veeraraghavan Ramachandran
- Herbert C Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States
| | - Pravin D. Gagare
- Herbert C Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States
| | - Debarshi Pratihar
- Herbert C Brown Center for Borane Research, Department of Chemistry, Purdue University, West Lafayette, IN 47907, United States
| | - Charles R. Ashby
- Department of Pharmaceutical Sciences, College of Pharmacy and Allied Health Professions, Saint John's University, Jamaica, NY 11439, United States
| | - Eliot L. Gardner
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States
| | - Zheng-Xiong Xi
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, United States, Corresponding author at: 5500 Nathan Shock Drive, Baltimore, MD 21224, United States. Tel.: +1 410 550 1749; fax: +1 410 550 5172. E-mail address: (Z.-X. Xi)
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Does gabapentin lead to early symptom improvement in obsessive-compulsive disorder? Eur Arch Psychiatry Clin Neurosci 2008; 258:319-23. [PMID: 18297416 DOI: 10.1007/s00406-007-0798-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 11/19/2007] [Indexed: 10/22/2022]
Abstract
OBJECTIVE The aim of this study was to compare efficacy of fluoxetine alone and co-administration of gabapentin and fluoxetine in patients with obsessive compulsive disorder (OCD). METHODS Forty outpatients with a DSM-IV diagnosis of OCD were randomized to open label treatment, 20 of whom were treated with fluoxetine alone and the remaining 20 with fluoxetine plus gabapentin during 8 weeks. The severity was assessed by Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and Clinical Global Impression (CGI). RESULTS Final CGI-I and Y-BOCS scores were not significantly different in both groups. However, in repeated measures ANOVA, compared to fluoxetine group, we found significantly a better improvement in the fluoxetine plus gabapentin group at week 2 by means of YBOCS and CGI-I scores. Comparisons on weeks 4, 6 and 8 revealed no statistical differences between the groups. There was no significant difference of adverse effects between two groups. CONCLUSIONS Adding gabapentin to fluoxetine in the treatment of OCD seems to shorten the time to onset of fluoxetine's anti-obsessive effect without a significant increase in adverse effects. In order to accelerate the clinical response, co-administration of fluoxetine and gabapentin may be a preferable strategy. On the other hand, further controlled studies are needed to support this finding.
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Rocha L. Subchronic treatment with antiepileptic drugs modifies pentylenetetrazol-induced seizures in mice: Its correlation with benzodiazepine receptor binding. Neuropsychiatr Dis Treat 2008; 4:619-25. [PMID: 18830436 PMCID: PMC2526378 DOI: 10.2147/ndt.s2118] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Experiments using male CD1 mice were carried out to investigate the effects of subchronic (daily administration for 8 days) pretreatments with drugs enhancing GABAergic transmission (diazepam, 10 mg/kg, ip; gabapentin, 100 mg/kg, po; or vigabatrin, 500 mg/kg, po) on pentylenetetrazol (PTZ)-induced seizures, 24 h after the last injection. Subchronic administration of diazepam reduced latencies to clonus, tonic extension and death induced by PTZ. Subchronic vigabatrin produced enhanced latency to the first clonus but faster occurrence of tonic extension and death induced by PTZ. Subchronic gabapentin did not modify PTZ-induced seizures. Autoradiography experiments revealed reduced benzodiazepine receptor binding in several brain areas after subchronic treatment with diazepam or gabapentin, whereas subchronic vigabatrin did not induce significant receptor changes. The present results indicate differential effects induced by the subchronic administration of diazepam, vigabatrin, and gabapentin on the susceptibility to PTZ-induced seizures, benzodiazepine receptor binding, or both.
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Affiliation(s)
- Luisa Rocha
- Pharmacobiology Department, Center for Research and Advanced Studies Calz, Tenorios, México.
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46
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Gil S, Parra M, Rodríguez P. An efficient synthesis of gamma-amino acids and attempts to drive its enantioselectivity. Molecules 2008; 13:716-28. [PMID: 18463573 PMCID: PMC6245315 DOI: 10.3390/molecules13040716] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 03/26/2008] [Accepted: 03/26/2008] [Indexed: 11/30/2022] Open
Abstract
Addition of carboxylic acid dianions to bromoacetonitrile lead, in good yields,to the corresponding gamma-cyanoacids, which on hydrogenation yielded gamma-amino acids. This two step methodology improves upon previously described results. Poor e.e's resultedfrom our attempts to drive the enantioselectivity of this transformation by chiral amide induction.
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Affiliation(s)
| | - Margarita Parra
- Department de Organic Chemistry, Universitat de València, Dr. Moliner 50, 46100 Burjassot, Spain. Fax +34(9)63543831; E-mails: ;
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Upton N. Meeting Highlights: 1st Meeting of the European Congress of Epileptology 6–10 September, 1994, Oporto, Portugal. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.3.12.1333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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48
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Development and application of a validated HPLC method for the analysis of dissolution samples of gabapentin drug products. J Pharm Biomed Anal 2008; 46:181-6. [DOI: 10.1016/j.jpba.2007.08.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 07/19/2007] [Accepted: 08/28/2007] [Indexed: 11/21/2022]
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49
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Mannoury la Cour C, Herbelles C, Pasteau V, de Nanteuil G, Millan MJ. Influence of positive allosteric modulators on GABA(B) receptor coupling in rat brain: a scintillation proximity assay characterisation of G protein subtypes. J Neurochem 2007; 105:308-23. [PMID: 18021295 DOI: 10.1111/j.1471-4159.2007.05131.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Little is known concerning coupling of cerebral GABA(B) receptors to G protein subtypes, and the influence of positive allosteric modulators (PAMs) has not been evaluated. These questions were addressed by an antibody-capture/scintillation proximity assay strategy. GABA concentration-dependently enhanced the magnitude of [(35)S]GTPgammaS binding to Galphao and, less markedly, Galphai(1/3) in cortex, whereas Gq and Gs/olf were unaffected. (R)-baclofen and SKF97581 likewise activated Galphao and Galphai(1/3), expressing their actions more potently than GABA. Similar findings were acquired in hippocampus and cerebellum, and the GABA(B) antagonist, CGP55845A, abolished agonist-induced activation of Galphao and Galphai(1/3) in all structures. The PAMs, GS39783, CGP7930 and CGP13501, inactive alone, enhanced efficacy and potency of agonist-induced [(35)S]GTPgammaS binding to Galphao in all regions, actions abolished by CGP55845A. In contrast, they did not modify efficacies at Galphai(1/3). Similarly, in human embryonic kidney cells expressing GABA(B(1a+2)) or GABA(B(1b+2)) receptors, allosteric modulators did not detectably enhance efficacy of GABA at Galphai(1/3), though they increased its potency. To summarise, GABA(B) receptors coupled both to Galphao and to Galphai, but not Gq and Gs/olf, in rat brain. PAMs more markedly enhanced efficacy of coupling to Go versus Gi(1/3). It will be of interest to confirm these observations employing complementary techniques and to evaluate their potential therapeutic significance.
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Akat H, Yildirim Y, Yurt Lambrecht F, Yilmaz O, Balcan M, Duman Y. Biological distribution of iodo-allyl gabapentin and iodo-gabapentin. J Radioanal Nucl Chem 2007. [DOI: 10.1007/s10967-007-7014-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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