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Wright NJD. A review of the direct targets of the cannabinoids cannabidiol, Δ9-tetrahydrocannabinol, N-arachidonoylethanolamine and 2-arachidonoylglycerol. AIMS Neurosci 2024; 11:144-165. [PMID: 38988890 PMCID: PMC11230856 DOI: 10.3934/neuroscience.2024009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 04/17/2024] [Accepted: 04/19/2024] [Indexed: 07/12/2024] Open
Abstract
Marijuana has been used by humans for thousands of years for both medicinal and recreational purposes. This included the treatment of pain, inflammation, seizures, and nausea. In the 1960s, the structure of the principal psychoactive ingredient Δ9-tetrahydrocannabinol was determined, and over the next few decades, two cannabinoid receptors were characterized along with the human endocannabinoid system and what it affects. This includes metabolism, the cardiovascular and reproductive systems, and it is involved in such conditions as inflammation, cancer, glaucoma, and liver and musculoskeletal disorders. In the central nervous system, the endocannabinoid system has been linked to appetite, learning, memory, and conditions such as depression, anxiety, schizophrenia, stroke, multiple sclerosis, neurodegeneration, addiction, and epilepsy. It was the profound effectiveness of cannabidiol, a non-psychoactive ingredient of marijuana, to relieve the symptoms of Dravet syndrome, a severe form of childhood epilepsy, that recently helped spur marijuana research. This has helped substantially to change society's attitude towards this potential source of useful drugs. However, research has also revealed that the actions of endocannabinoids, such as anandamide and 2-arachidonoylglycerol, and the phytocannabinoids, tetrahydrocannabinol and cannabidiol, were not just due to interactions with the two cannabinoid receptors but by acting directly on many other targets including various G-protein receptors and cation channels, such as the transient receptor potential channels for example. This mini-review attempts to survey the effects of these 4 important cannabinoids on these currently identified targets.
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Oz M, Lorke DE, Howarth FC. Transient receptor potential vanilloid 1 (TRPV1)-independent actions of capsaicin on cellular excitability and ion transport. Med Res Rev 2023. [PMID: 36916676 DOI: 10.1002/med.21945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 01/17/2023] [Accepted: 02/26/2023] [Indexed: 03/15/2023]
Abstract
Capsaicin is a naturally occurring alkaloid derived from chili pepper that is responsible for its hot pungent taste. Capsaicin is known to exert multiple pharmacological actions, including analgesia, anticancer, anti-inflammatory, antiobesity, and antioxidant effects. The transient receptor potential vanilloid subfamily member 1 (TRPV1) is the main receptor mediating the majority of the capsaicin effects. However, numerous studies suggest that the TRPV1 receptor is not the only target for capsaicin. An increasing number of studies indicates that capsaicin, at low to mid µM ranges, not only indirectly through TRPV1-mediated Ca2+ increases, but also directly modulates the functions of voltage-gated Na+ , K+ , and Ca2+ channels, as well as ligand-gated ion channels and other ion transporters and enzymes involved in cellular excitability. These TRPV1-independent effects are mediated by alterations of the biophysical properties of the lipid membrane and subsequent modulation of the functional properties of ion channels and by direct binding of capsaicin to the channels. The present study, for the first time, systematically categorizes this diverse range of non-TRPV1 targets and discusses cellular and molecular mechanisms mediating TRPV1-independent effects of capsaicin in excitable, as well as nonexcitable cells.
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Affiliation(s)
- Murat Oz
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat, Kuwait
| | - Dietrich E Lorke
- Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates.,Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Frank C Howarth
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
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Fajardo L, Sanchez P, Salles J, Rigaudière JP, Patrac V, Caspar-Bauguil S, Bergoglgio C, Moro C, Walrand S, Le Bacquer O. Inhibition of the endocannabinoid system reverses obese phenotype in aged mice and partly restores skeletal muscle function. Am J Physiol Endocrinol Metab 2023; 324:E176-E184. [PMID: 36629822 DOI: 10.1152/ajpendo.00258.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Sarcopenia, the age-related loss of skeletal muscle mass, is associated with lipid accumulation and anabolic resistance; phenomena also observed in obesity and worsen when obesity and aging are combined. The endocannabinoid system (ECS) is overactivated in obesity, but its role in aging obesity-related muscle dysfunction is unknown. The aims of this study were to evaluate the effect of inhibition of the ECS by rimonabant (RIM) on the metabolic alterations induced by a high-fat high-sucrose diet and on skeletal muscle mass/function in aged mice. Eighteen-month-old male mice were subjected to a control (CTL) or a high-fat high-sucrose (HFHS) diet for 24 weeks. Mice were administered with saline or RIM (10 mg/kg/day) for the last 4 weeks of the diet. Skeletal muscle function was evaluated by open-field, rotarod, and grip strength tests. Metabolic alterations in liver, adipose tissue, and skeletal muscle were investigated by quantitative RT-PCR. Body mass was higher in HFHS mice compared to CTL mice (48.0 ± 1.5 vs. 33.5 ± 0.7 g, P < 0.01), as a result of fat accumulation (34.8 ± 1.0 vs. 16.7 ± 0.8%, P < 0.01). RIM reduced body fat mass in both CTL (-16%, P < 0.05) and HFHS conditions (-40%, P < 0.01), without affecting hindlimb skeletal muscle mass. In HFHS mice, grip strength evolution was improved (-0.29 ± 0.06 vs. -0.49 ± 0.06 g/g lean mass, P < 0.05), and rotarod activity was increased by ≈60% in response to RIM (45.9 ± 6.3 vs. 28.5 ± 4.6 cm, P < 0.05). Lipolysis and β-oxidation genes were upregulated in the liver as well as genes involved in adipose tissue browning. These results demonstrate that inhibition of the ECS induces metabolic changes in liver and adipose tissue associated with a reversion of the obese phenotype and that RIM is able to improve motor coordination and muscle strength in aged mice, without affecting skeletal muscle mass.NEW & NOTEWORTHY In 24-month-old mice submitted to high-fat high-sucrose-induced obesity, inhibition of the endocannabinoid system by rimonabant reversed the obese phenotype by promoting adipose tissue browning and β-oxidation in the liver but not in skeletal muscle. These metabolism modifications are associated with improved skeletal muscle function.
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Affiliation(s)
- Lucas Fajardo
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Phelipe Sanchez
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jérôme Salles
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jean Paul Rigaudière
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Véronique Patrac
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Sylvie Caspar-Bauguil
- Team MetaDiab, Institute of Metabolic and Cardiovascular Diseases (I2MC), Inserm/Paul Sabatier University UMR1297, Toulouse, France
- Department of Clinical Biochemistry, Toulouse University Hospitals, Toulouse, France
| | - Camille Bergoglgio
- Team MetaDiab, Institute of Metabolic and Cardiovascular Diseases (I2MC), Inserm/Paul Sabatier University UMR1297, Toulouse, France
| | - Cédric Moro
- Team MetaDiab, Institute of Metabolic and Cardiovascular Diseases (I2MC), Inserm/Paul Sabatier University UMR1297, Toulouse, France
| | - Stéphane Walrand
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
- Service de Nutrition Clinique, Hôpital Gabriel Montpied, Centre Hospitalier Universitaire (CHU) Clermont-Ferrand, Clermont-Ferrand, France
| | - Olivier Le Bacquer
- Unité de Nutrition Humaine (UNH), Institut National de la Recherche Agronomique (INRAE), Université Clermont Auvergne, Clermont-Ferrand, France
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Oz M, Yang KHS, Mahgoub MO. Effects of cannabinoids on ligand-gated ion channels. Front Physiol 2022; 13:1041833. [PMID: 36338493 PMCID: PMC9627301 DOI: 10.3389/fphys.2022.1041833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/06/2022] [Indexed: 11/13/2022] Open
Abstract
Phytocannabinoids such as Δ9-tetrahydrocannabinol and cannabidiol, endocannabinoids such as N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol, and synthetic cannabinoids such as CP47,497 and JWH-018 constitute major groups of structurally diverse cannabinoids. Along with these cannabinoids, CB1 and CB2 cannabinoid receptors and enzymes involved in synthesis and degradation of endocannabinoids comprise the major components of the cannabinoid system. Although, cannabinoid receptors are known to be involved in anti-convulsant, anti-nociceptive, anti-psychotic, anti-emetic, and anti-oxidant effects of cannabinoids, in recent years, an increasing number of studies suggest that, at pharmacologically relevant concentrations, these compounds interact with several molecular targets including G-protein coupled receptors, ion channels, and enzymes in a cannabinoid-receptor independent manner. In this report, the direct actions of endo-, phyto-, and synthetic cannabinoids on the functional properties of ligand-gated ion channels and the plausible mechanisms mediating these effects were reviewed and discussed.
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Affiliation(s)
- Murat Oz
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Kuwait City, Kuwait
- *Correspondence: Murat Oz,
| | - Keun-Hang Susan Yang
- Department of Biological Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA, United States
| | - Mohamed Omer Mahgoub
- Department of Health and Medical Sciences, Khawarizmi International College, Abu Dhabi, UAE
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Isaev D, Yang KHS, Shabbir W, Howarth FC, Oz M. Capsaicin Inhibits Multiple Voltage-Gated Ion Channels in Rabbit Ventricular Cardiomyocytes in TRPV1-Independent Manner. Pharmaceuticals (Basel) 2022; 15:ph15101187. [PMID: 36297299 PMCID: PMC9611941 DOI: 10.3390/ph15101187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/19/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
Capsaicin is a naturally occurring alkaloid derived from chili pepper which is responsible for its hot, pungent taste. It exerts multiple pharmacological actions, including pain-relieving, anti-cancer, anti-inflammatory, anti-obesity, and antioxidant effects. Previous studies have shown that capsaicin significantly affects the contractility and automaticity of the heart and alters cardiovascular functions. In this study, the effects of capsaicin were investigated on voltage-gated ion currents in rabbit ventricular myocytes. Capsaicin inhibited rapidly activated (IKr) and slowly activated (IKs) K+ currents and transient outward (Ito) K+ current with IC50 values of 3.4 µM,14.7 µM, and 9.6 µM, respectively. In addition, capsaicin, at higher concentrations, suppressed voltage-gated Na+ and Ca2+ currents and inward rectifier IK1 current with IC50 values of 42.7 µM, 34.9 µM, and 38.8 µM, respectively. Capsaicin inhibitions of INa, IL-Ca, IKr, IKs, Ito, and IK1 were not reversed in the presence of capsazepine (3 µM), a TRPV1 antagonist. The inhibitory effects of capsaicin on these currents developed gradually, reaching steady-state levels within 3 to 6 min, and the recoveries were usually incomplete during washout. In concentration-inhibition curves, apparent Hill coefficients higher than unity suggested multiple interaction sites of capsaicin on these channels. Collectively, these findings indicate that capsaicin affects cardiac electrophysiology by acting on a diverse range of ion channels and suggest that caution should be exercised when capsaicin is administered to carriers of cardiac channelopathies or to individuals with arrhythmia-prone conditions, such as ischemic heart diseases.
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Affiliation(s)
- Dmytro Isaev
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, 01024 Kiev, Ukraine
| | - Keun-Hang Susan Yang
- Department of Biological Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Waheed Shabbir
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, 01024 Kiev, Ukraine
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Abu Dhabi 15551, United Arab Emirates
| | - Murat Oz
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat 13110, Kuwait
- Correspondence: ; Tel.: +965-99758003
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Ge D, Odierna GL, Phillips WD. Influence of cannabinoids upon nerve-evoked skeletal muscle contraction. Neurosci Lett 2020; 725:134900. [DOI: 10.1016/j.neulet.2020.134900] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 02/07/2023]
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Cruz SL, Sánchez-Miranda E, Castillo-Arellano JI, Cervantes-Villagrana RD, Ibarra-Sánchez A, González-Espinosa C. Anandamide inhibits FcεRI-dependent degranulation and cytokine synthesis in mast cells through CB 2 and GPR55 receptor activation. Possible involvement of CB 2-GPR55 heteromers. Int Immunopharmacol 2018; 64:298-307. [PMID: 30243065 DOI: 10.1016/j.intimp.2018.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 11/25/2022]
Abstract
Activation of high affinity receptor for IgE (FcεRI) by IgE/antigen complexes in mast cells (MCs) leads to the release of preformed pro-inflammatory mediators stored in granules by a Ca2+-dependent process known as anaphylactic degranulation. Degranulation inhibition has been proposed as a strategy to control allergies and chronic inflammation conditions. Cannabinoids are important inhibitors of inflammatory reactions but their effects on IgE/Ag-mediated MCs responses are not well described. In this study, we analyzed the effect of the endocannabinoid anandamide (AEA), the selective CB2 receptor agonist HU308, and the GPR55 receptor agonist lysophosphatidylinositol (LPI) on FcεRI-induced activation in murine bone marrow-derived mast cells (BMMCs). Our results show that AEA, HU380 and LPI inhibited FcεRI-induced degranulation in a concentration-dependent manner. This effect was mediated by CB2 and GPR55 receptor activation through a mechanism insensitive to pertussis toxin. Degranulation inhibition was prevented by CB2 and GPR55 antagonism, but not by CB1 receptor blockage. AEA also inhibited calcium-dependent cytokine mRNA synthesis induced by FcεRI crosslinking, without affecting early phosphorylation events. In addition, AEA, HU308 and LPI inhibited intracellular Ca2+ rise in response to IgE/Ag. CB2 and GPR55 receptor antagonism could not prevent the inhibition produced by AEA and HU308, but partially blocked the one caused by LPI. These results indicate that AEA inhibits IgE/Ag-induced degranulation through a mechanism that includes the participation of CB2 and GPR55 receptors acting in close crosstalk, and show that CB2-GPR55 heteromers are important negative regulators of FcεRI-induced responses in MCs.
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Affiliation(s)
- Silvia L Cruz
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico.
| | - Elizabeth Sánchez-Miranda
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico; Departamento de Sistemas Biológicos, Universidad Autónoma Metropolitana Xochimilco, Mexico City, Mexico
| | - Jorge Ivan Castillo-Arellano
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico
| | - Rodolfo Daniel Cervantes-Villagrana
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico
| | - Alfredo Ibarra-Sánchez
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico
| | - Claudia González-Espinosa
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Sede Sur, Mexico.
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Cannabinoid CB1 and CB2 receptors differentially modulate L- and T-type Ca 2+ channels in rat retinal ganglion cells. Neuropharmacology 2017; 124:143-156. [PMID: 28431968 DOI: 10.1016/j.neuropharm.2017.04.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/15/2017] [Accepted: 04/17/2017] [Indexed: 01/09/2023]
Abstract
Endocannabinoid signaling system is involved in regulating multiple neuronal functions in the central nervous system by activating G-protein coupled cannabinoid CB1 and CB2 receptors (CB1Rs and CB2Rs). Growing evidence has shown that CB1Rs and CB2Rs are extensively expressed in retinal ganglion cells (RGCs). Here, modulation of L- and T-types Ca2+ channels by activating CB1Rs and CB2Rs in RGCs was investigated. Triple immunofluorescent staining showed that L-type subunit CaV1.2 was co-localized with T-type subunits (CaV3.1, CaV3.2 and CaV3.3) in rat RGCs. In acutely isolated rat RGCs, the CB1R agonist WIN55212-2 suppressed both peak and steady-state Ca2+ currents in a dose-dependent manner, with IC50 being 9.6 μM and 8.4 μM, respectively. It was further shown that activation of CB1Rs by WIN55212-2 or ACEA, another CB1R agonist, significantly suppressed both L- and T-type Ca2+ currents, and shifted inactivation curve of T-type one toward hyperpolarization direction. While the effect on L-type Ca2+ channels was mediated by intracellular cAMP/protein kinase A (PKA), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) and calcium/calmodulin-dependent protein kinase II (CaMKII) signaling pathways, only CaMKII signaling pathway was involved in the effect on T-type Ca2+ channels. Furthermore, CB65 and HU308, two specific CB2R agonists, significantly suppressed T-type Ca2+ channels, which was mediated by intracellular cAMP/PKA and CaMKII signaling pathways, but had no effect on L-type channels. These results imply that endogenous cannabinoids may modulate the excitability and the output of RGCs by differentially suppressing the activity of L- and T-type Ca2+ channels through activation of CB1Rs and CB2Rs. This article is part of the Special Issue entitled "A New Dawn in Cannabinoid Neurobiology".
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Elinder F, Liin SI. Actions and Mechanisms of Polyunsaturated Fatty Acids on Voltage-Gated Ion Channels. Front Physiol 2017; 8:43. [PMID: 28220076 PMCID: PMC5292575 DOI: 10.3389/fphys.2017.00043] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/16/2017] [Indexed: 01/29/2023] Open
Abstract
Polyunsaturated fatty acids (PUFAs) act on most ion channels, thereby having significant physiological and pharmacological effects. In this review we summarize data from numerous PUFAs on voltage-gated ion channels containing one or several voltage-sensor domains, such as voltage-gated sodium (NaV), potassium (KV), calcium (CaV), and proton (HV) channels, as well as calcium-activated potassium (KCa), and transient receptor potential (TRP) channels. Some effects of fatty acids appear to be channel specific, whereas others seem to be more general. Common features for the fatty acids to act on the ion channels are at least two double bonds in cis geometry and a charged carboxyl group. In total we identify and label five different sites for the PUFAs. PUFA site 1: The intracellular cavity. Binding of PUFA reduces the current, sometimes as a time-dependent block, inducing an apparent inactivation. PUFA site 2: The extracellular entrance to the pore. Binding leads to a block of the channel. PUFA site 3: The intracellular gate. Binding to this site can bend the gate open and increase the current. PUFA site 4: The interface between the extracellular leaflet of the lipid bilayer and the voltage-sensor domain. Binding to this site leads to an opening of the channel via an electrostatic attraction between the negatively charged PUFA and the positively charged voltage sensor. PUFA site 5: The interface between the extracellular leaflet of the lipid bilayer and the pore domain. Binding to this site affects slow inactivation. This mapping of functional PUFA sites can form the basis for physiological and pharmacological modifications of voltage-gated ion channels.
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Affiliation(s)
- Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
| | - Sara I Liin
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
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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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Yang W, Li Q, Wang SY, Gao F, Qian WJ, Li F, Ji M, Sun XH, Miao Y, Wang Z. Cannabinoid receptor agonists modulate calcium channels in rat retinal müller cells. Neuroscience 2016; 313:213-24. [DOI: 10.1016/j.neuroscience.2015.11.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/10/2015] [Accepted: 11/17/2015] [Indexed: 10/22/2022]
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Al Kury LT, Voitychuk OI, Yang KHS, Thayyullathil FT, Doroshenko P, Ramez AM, Shuba YM, Galadari S, Howarth FC, Oz M. Effects of the endogenous cannabinoid anandamide on voltage-dependent sodium and calcium channels in rat ventricular myocytes. Br J Pharmacol 2015; 171:3485-98. [PMID: 24758718 DOI: 10.1111/bph.12734] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 02/17/2014] [Accepted: 03/14/2014] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE The endocannabinoid anandamide (N-arachidonoyl ethanolamide; AEA) exerts negative inotropic and antiarrhythmic effects in ventricular myocytes. EXPERIMENTAL APPROACH Whole-cell patch-clamp technique and radioligand-binding methods were used to analyse the effects of anandamide in rat ventricular myocytes. KEY RESULTS In the presence of 1-10 μM AEA, suppression of both Na(+) and L-type Ca(2+) channels was observed. Inhibition of Na(+) channels was voltage and Pertussis toxin (PTX) - independent. Radioligand-binding studies indicated that specific binding of [(3) H] batrachotoxin (BTX) to ventricular muscle membranes was also inhibited significantly by 10 μM metAEA, a non-metabolized AEA analogue, with a marked decrease in Bmax values but no change in Kd . Further studies on L-type Ca(2+) channels indicated that AEA potently inhibited these channels (IC50 0.1 μM) in a voltage- and PTX-independent manner. AEA inhibited maximal amplitudes without affecting the kinetics of Ba(2+) currents. MetAEA also inhibited Na(+) and L-type Ca(2+) currents. Radioligand studies indicated that specific binding of [(3) H]isradipine, was inhibited significantly by metAEA. (10 μM), changing Bmax but not Kd . CONCLUSION AND IMPLICATIONS Results indicate that AEA inhibited the function of voltage-dependent Na(+) and L-type Ca(2+) channels in rat ventricular myocytes, independent of CB1 and CB2 receptor activation.
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Affiliation(s)
- Lina T Al Kury
- Laboratory of Functional Lipidomics, Department of Pharmacology, UAE University, Al Ain, UAE
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Ali RM, Al Kury LT, Yang KHS, Qureshi A, Rajesh M, Galadari S, Shuba YM, Howarth FC, Oz M. Effects of cannabidiol on contractions and calcium signaling in rat ventricular myocytes. Cell Calcium 2015; 57:290-9. [PMID: 25711828 DOI: 10.1016/j.ceca.2015.02.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/20/2015] [Accepted: 02/02/2015] [Indexed: 02/03/2023]
Abstract
Cannabidiol (CBD), a major nonpsychotropic cannabinoid found in Cannabis plant, has been shown to influence cardiovascular functions under various physiological and pathological conditions. In the present study, the effects of CBD on contractility and electrophysiological properties of rat ventricular myocytes were investigated. Video edge detection was used to measure myocyte shortening. Intracellular Ca(2+) was measured in cells loaded with the Ca(2+) sensitive fluorescent indicator fura-2 AM. Whole-cell patch clamp was used to measure action potential and Ca(2+) currents. Radioligand binding was employed to study pharmacological characteristics of CBD binding. CBD (1μM) caused a significant decrease in the amplitudes of electrically evoked myocyte shortening and Ca(2+) transients. However, the amplitudes of caffeine-evoked Ca(2+) transients and the rate of recovery of electrically evoked Ca(2+) transients following caffeine application were not altered. CBD (1μM) significantly decreased the duration of APs. Further studies on L-type Ca(2+) channels indicated that CBD inhibits these channels with IC50 of 0.1μM in a voltage-independent manner. Radioligand studies indicated that the specific binding of [(3)H]Isradipine, was not altered significantly by CBD. The results suggest that CBD depresses myocyte contractility by suppressing L-type Ca(2+) channels at a site different than dihydropyridine binding site and inhibits excitation-contraction coupling in cardiomyocytes.
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Affiliation(s)
- Ramez M Ali
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Lina T Al Kury
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates; Department of Natural Science and Public Health, College of Sustainability Sciences and Humanities, Zayed University, Abu Dhabi, United Arab Emirates
| | - Keun-Hang Susan Yang
- Department of Biological Sciences, Schmid College of Science and Engineering, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Anwar Qureshi
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Mohanraj Rajesh
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Sehamuddin Galadari
- Department of Biochemistry, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Yaroslav M Shuba
- Bogomoletz Institute of Physiology and International Center of Molecular Physiology, National Academy of Sciences of Ukraine, Kyiv-24, Ukraine
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Murat Oz
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates.
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Golovko T, Min R, Lozovaya N, Falconer C, Yatsenko N, Tsintsadze T, Tsintsadze V, Ledent C, Harvey RJ, Belelli D, Lambert JJ, Rozov A, Burnashev N. Control of Inhibition by the Direct Action of Cannabinoids on GABAAReceptors. Cereb Cortex 2014; 25:2440-55. [DOI: 10.1093/cercor/bhu045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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15
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Al Kury LT, Yang KHS, Thayyullathil FT, Rajesh M, Ali RM, Shuba YM, Howarth FC, Galadari S, Oz M. Effects of endogenous cannabinoid anandamide on cardiac Na⁺/Ca²⁺ exchanger. Cell Calcium 2014; 55:231-7. [PMID: 24674601 DOI: 10.1016/j.ceca.2014.02.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/17/2014] [Accepted: 02/23/2014] [Indexed: 10/25/2022]
Abstract
Endocannabinoid anandamide (N-arachidonoyl ethanolamide; AEA) has been shown to cause negative inotropic and antiarrhythmic effects in ventricular myocytes. In this study, using whole-cell patch clamp technique, we have investigated the effects of AEA on cardiac Na(+)/Ca(2+) exchanger (NCX1)-mediated currents. AEA suppressed NCX1 with an IC50 value of 4.7 μM. Both inward and outward components of exchanger currents were suppressed by AEA equally. AEA inhibition was mimicked by the metabolically stable analogue, methanandamide (metAEA, 10 μM) while it was not influenced by inhibition of fatty acid amide hydrolase with 1 μM URB597 incubation. The effect of AEA, was not altered in the presence of cannabinoid receptor 1 and 2 antagonists AM251 (1 μM) and AM630 (1 μM), respectively. In addition, inhibition by AEA remained unchanged after pertussis toxin (PTX, 2 μg/ml) treatment or following the inclusion of GDP-β-S (1 mM) in pipette solution. Currents mediated by NCX1 expressed in HEK-293 cells were also inhibited by 10 μM AEA a partially reversible manner. Confocal microscopy images indicated that the intensity of YFP-NCX1 expression on cell surface was not altered by AEA. Collectively, the results indicate that AEA directly inhibits the function of NCX1 in rat ventricular myocytes and in HEK-293 cells expressing NCX1.
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Affiliation(s)
- Lina T Al Kury
- Laboratory of Functional Lipidomics, Department of Pharmacology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Keun-Hang Susan Yang
- Department of Biological Sciences, Schmid College of Science and Engineering, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Faisal T Thayyullathil
- Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Mohanraj Rajesh
- Laboratory of Functional Lipidomics, Department of Pharmacology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Ramez M Ali
- Laboratory of Functional Lipidomics, Department of Pharmacology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Yaroslav M Shuba
- Bogomoletz Institute of Physiology and International Center of Molecular Physiology, National Academy of Sciences of Ukraine, Kyiv 24, Ukraine
| | - Frank Christopher Howarth
- Department of Physiology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Sehamuddin Galadari
- Department of Biochemistry, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates
| | - Murat Oz
- Laboratory of Functional Lipidomics, Department of Pharmacology, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab Emirates.
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16
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Al Kury LT, Voitychuk OI, Ali RM, Galadari S, Yang KHS, Howarth FC, Shuba YM, Oz M. Effects of endogenous cannabinoid anandamide on excitation-contraction coupling in rat ventricular myocytes. Cell Calcium 2014; 55:104-18. [PMID: 24472666 DOI: 10.1016/j.ceca.2013.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/25/2013] [Accepted: 12/26/2013] [Indexed: 02/08/2023]
Abstract
A role for anandamide (N-arachidonoyl ethanolamide; AEA), a major endocannabinoid, in the cardiovascular system in various pathological conditions has been reported in earlier reports. In the present study, the effects of AEA on contractility, Ca2+ signaling, and action potential (AP) characteristics were investigated in rat ventricular myocytes. Video edge detection was used to measure myocyte shortening. Intracellular Ca2+ was measured in cells loaded with the fluorescent indicator fura-2 AM. AEA (1 μM) caused a significant decrease in the amplitudes of electrically evoked myocyte shortening and Ca2+ transients. However, the amplitudes of caffeine-evoked Ca2+ transients and the rate of recovery of electrically evoked Ca2+ transients following caffeine application were not altered. Biochemical studies in sarcoplasmic reticulum (SR) vesicles from rat ventricles indicated that AEA affected Ca2+ -uptake and Ca2+ -ATPase activity in a biphasic manner. [3H]-ryanodine binding and passive Ca2+ release from SR vesicles were not altered by 10 μM AEA. Whole-cell patch-clamp technique was employed to investigate the effect of AEA on the characteristics of APs. AEA (1 μM) significantly decreased the duration of AP. The effect of AEA on myocyte shortening and AP characteristics was not altered in the presence of pertussis toxin (PTX, 2 μg/ml for 4 h), AM251 and SR141716 (cannabinoid type 1 receptor antagonists; 0.3 μM) or AM630 and SR 144528 (cannabinoid type 2 receptor antagonists; 0.3 μM). The results suggest that AEA depresses ventricular myocyte contractility by decreasing the action potential duration (APD) in a manner independent of CB1 and CB2 receptors.
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MESH Headings
- Action Potentials/drug effects
- Animals
- Arachidonic Acids/pharmacology
- Caffeine/pharmacology
- Calcium/analysis
- Calcium/metabolism
- Calcium Signaling/drug effects
- Endocannabinoids/pharmacology
- Fura-2/chemistry
- Heart Ventricles/cytology
- In Vitro Techniques
- Indoles/pharmacology
- Male
- Myocardial Contraction/drug effects
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Pertussis Toxin/toxicity
- Piperidines/pharmacology
- Polyunsaturated Alkamides/pharmacology
- Pyrazoles/pharmacology
- Rats
- Rats, Wistar
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Cannabinoid, CB2/antagonists & inhibitors
- Receptor, Cannabinoid, CB2/metabolism
- Sarcoplasmic Reticulum/metabolism
- Transport Vesicles/drug effects
- Transport Vesicles/metabolism
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Affiliation(s)
- Lina T Al Kury
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Oleg I Voitychuk
- Bogomoletz Institute of Physiology and International Center of Molecular Physiology, National Academy of Sciences of Ukraine, Kyiv-24, Ukraine
| | - Ramiz M Ali
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Sehamuddin Galadari
- Department of Biochemistry, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Keun-Hang Susan Yang
- Department of Biological Sciences, Schmid College of Science and Engineering, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Frank Christopher Howarth
- Department of Physiology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates
| | - Yaroslav M Shuba
- Bogomoletz Institute of Physiology and International Center of Molecular Physiology, National Academy of Sciences of Ukraine, Kyiv-24, Ukraine
| | - Murat Oz
- Laboratory of Functional Lipidomics, Department of Pharmacology, College of Medicine and Health Sciences, UAE University, Al Ain, Abu Dhabi, United Arab Emirates.
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Thr136Ile polymorphism of human vesicular monoamine transporter-1 (SLC18A1 gene) influences its transport activity in vitro. Neural Plast 2013; 2012:945373. [PMID: 23213575 PMCID: PMC3504448 DOI: 10.1155/2012/945373] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/22/2012] [Accepted: 09/23/2012] [Indexed: 12/23/2022] Open
Abstract
The hippocampus has the extraordinary capacity to process and store information. Consequently, there is an intense interest in the mechanisms that underline learning and memory. Synaptic plasticity has been hypothesized to be the neuronal substrate for learning. Ca2+ and Ca2+-activated kinases control cellular processes of most forms of hippocampal synapse plasticity. In this paper, I aim to integrate our current understanding of Ca2+-mediated synaptic plasticity and metaplasticity in motivational and reward-related learning in the hippocampus. I will introduce two representative neuromodulators that are widely studied in reward-related learning (e.g., ghrelin and endocannabinoids) and show how they might contribute to hippocampal neuron activities and Ca2+-mediated signaling processes in synaptic plasticity. Additionally, I will discuss functional significance of these two systems and their signaling pathways for its relevance to maladaptive reward learning leading to addiction.
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18
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Voitychuk OI, Asmolkova VS, Gula NM, Sotkis GV, Galadari S, Howarth FC, Oz M, Shuba YM. Modulation of excitability, membrane currents and survival of cardiac myocytes by N-acylethanolamines. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:1167-76. [DOI: 10.1016/j.bbalip.2012.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 04/17/2012] [Accepted: 05/11/2012] [Indexed: 12/21/2022]
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Spivak CE, Kim W, Liu QR, Lupica CR, Doyle ME. Blockade of β-cell K(ATP) channels by the endocannabinoid, 2-arachidonoylglycerol. Biochem Biophys Res Commun 2012; 423:13-8. [PMID: 22609205 DOI: 10.1016/j.bbrc.2012.05.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 05/09/2012] [Indexed: 01/10/2023]
Abstract
The endocannabinoid system has been demonstrated to be active in the pancreatic β-cell. However the effects of the endocannabinoids (ECs) on insulin secretion are not well defined and may vary depending on the metabolic state of the β-cell. Specifically it is not known whether the effects of the ECs occur by activation of the cannabinoid receptors or via their direct interaction with the ion channels of the β-cell. To begin to delineate the effects of ECs on β-cell function, we examined how the EC, 2-AG influences β-cell ion channels in the absence of glucose stimulation. The mouse insulinoma cell line R7T1 was used to survey the effects of 2-AG on the high voltage activated (HVA) calcium, the delayed rectifier (K(v)), and the ATP-sensitive K (K(ATP)) channels by whole cell patch clamp recording. At 2mM glucose, 2-AG inhibited the HVA calcium (the majority of which are L-type channels), K(v), and K(ATP) channels. The channel exhibiting the most sensitivity to 2-AG blockade was the K(ATP) channel, where the IC(50) for 2-AG was 1 μM. Pharmacological agents revealed that the blockade of all these channels was independent of cannabinoid receptors. Our results provide a mechanism for the previous observations that CB1R agonists increase insulin secretion at low glucose concentrations through CB1R independent blockade of the K(ATP) channel.
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Affiliation(s)
- Charles E Spivak
- Cellular Neurobiology Branch, Electrophysiology Research Section, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA
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20
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L-type calcium channel mediates anticonvulsant effect of cannabinoids in acute and chronic murine models of seizure. Neurochem Res 2011; 37:279-87. [PMID: 21928146 DOI: 10.1007/s11064-011-0607-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/06/2011] [Accepted: 09/10/2011] [Indexed: 10/17/2022]
Abstract
The anticonvulsant activities of cannabinoid compounds have been shown in various models of seizure and epilepsy. At least, part of antiseizure effects of cannabinoid compounds is mediated through calcium (Ca(2+)) channels. The L-type Ca(2+) channels have been shown to be important in various epilepsy models. However, there is no data regarding the role of L-type Ca(2+) channels in protective action of cannabinoids on acute and chronic models of seizure. In this study, the effects of cannabinoid compounds and L-type Ca(2+) channels blockers, either alone or in combination were investigated using acute model of pentylenetetrazole (PTZ)-induced seizure in mice and chronic model electrical kindling of amygdala in rats. Pretreatment of mice with both cannabinoid CB1 receptor agonist arachidonyl-2'-chloroethylamide (ACEA) and endocannabinoid degradating enzyme inhibitor cyclohexylcarbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597) produced a protective effect against PTZ-induced seizure. Administration of various doses of the two L-type Ca(2+) channel blockers verapamil and diltiazem did not alter PTZ-induced seizure threshold. However, co-administration of verapamil and either ACEA or URB597 attenuated the protective effect of cannabinoid compounds against PTZ-induced seizure. Also, pretreatment of mice with diltiazem blocked the anticonvulsant activity of both ACEA and URB597. Moreover, (R)-(+)-[2,3-dihydro-5-methyl-3[(4-morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl) methanone mesylate (WIN55,212-2), the non-selective cannabinoid CB1 and CB2 receptor agonist showed anticonvulsant effect in amygdala-kindled rats. However, co-administration of WIN55,212-2 and verapamil attenuated the protective properties of WIN55,212-2. Our results showed that the anticonvulsant activity of cannabinoid compounds is mediated, at least in part, by L-type Ca(2+) channels in these two models of convulsion and epilepsy.
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Pertwee RG, Howlett AC, Abood ME, Alexander SPH, Di Marzo V, Elphick MR, Greasley PJ, Hansen HS, Kunos G, Mackie K, Mechoulam R, Ross RA. International Union of Basic and Clinical Pharmacology. LXXIX. Cannabinoid receptors and their ligands: beyond CB₁ and CB₂. Pharmacol Rev 2011; 62:588-631. [PMID: 21079038 DOI: 10.1124/pr.110.003004] [Citation(s) in RCA: 1171] [Impact Index Per Article: 90.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There are at least two types of cannabinoid receptors (CB(1) and CB(2)). Ligands activating these G protein-coupled receptors (GPCRs) include the phytocannabinoid Δ(9)-tetrahydrocannabinol, numerous synthetic compounds, and endogenous compounds known as endocannabinoids. Cannabinoid receptor antagonists have also been developed. Some of these ligands activate or block one type of cannabinoid receptor more potently than the other type. This review summarizes current data indicating the extent to which cannabinoid receptor ligands undergo orthosteric or allosteric interactions with non-CB(1), non-CB(2) established GPCRs, deorphanized receptors such as GPR55, ligand-gated ion channels, transient receptor potential (TRP) channels, and other ion channels or peroxisome proliferator-activated nuclear receptors. From these data, it is clear that some ligands that interact similarly with CB(1) and/or CB(2) receptors are likely to display significantly different pharmacological profiles. The review also lists some criteria that any novel "CB(3)" cannabinoid receptor or channel should fulfil and concludes that these criteria are not currently met by any non-CB(1), non-CB(2) pharmacological receptor or channel. However, it does identify certain pharmacological targets that should be investigated further as potential CB(3) receptors or channels. These include TRP vanilloid 1, which possibly functions as an ionotropic cannabinoid receptor under physiological and/or pathological conditions, and some deorphanized GPCRs. Also discussed are 1) the ability of CB(1) receptors to form heteromeric complexes with certain other GPCRs, 2) phylogenetic relationships that exist between CB(1)/CB(2) receptors and other GPCRs, 3) evidence for the existence of several as-yet-uncharacterized non-CB(1), non-CB(2) cannabinoid receptors; and 4) current cannabinoid receptor nomenclature.
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Affiliation(s)
- R G Pertwee
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, UK.
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22
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Mannucci C, Navarra M, Pieratti A, Russo GA, Caputi AP, Calapai G. Interactions between endocannabinoid and serotonergic systems in mood disorders caused by nicotine withdrawal. Nicotine Tob Res 2011; 13:239-47. [PMID: 21324836 DOI: 10.1093/ntr/ntq242] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Endocannabinoid and serotonin systems are implicated in mechanisms underlying depression-like symptoms. Involvement of serotonin in mood disorders occurring after smoking cessation has been observed. We studied the interactions between endocannabinoid and serotonergic systems in mood and behavioral disorders caused by nicotine cessation. The effects of the endocannabinoid transport inhibitor AM404 and the cannabinoid receptor 1 antagonist AM251 in a nicotine-dependent rodent model were investigated. METHODS Dependence was induced by subcutaneous injections of nicotine (2 mg/kg, 4 injections daily) for 15 consecutive days in mice. Animals treated with AM404 or AM251 were tested for locomotor activity and abstinence signs 24 hr after nicotine withdrawal and in forced swimming test (FST) at different times: immediately after last nicotine injection (t = 0) and 15 and 30 days after nicotine withdrawal. In nicotine-dependent mice treated with AM404 or AM251, expression of diencephalic serotonin receptor 1(A) (5-HT1(A)) was also measured. Effects of AM404, AM251, and WAY 100635 (5-HT(1A) receptor antagonist) in mice subjected to FST were evaluated. RESULTS A decrease in diencephalic 5-HT(1A) levels was observed in mice previously injected with nicotine. In the same animals, AM251 caused (0.5-2 mg/kg) a significant decrease of abstinence signs and AM404 (0.5-2 mg/kg) provoked a significant dose-dependent reduction in immobility time in the FST. Either AM251 or WAY 100635 antagonized anti-immobility effects of AM404. CONCLUSIONS Data indicate the existence of a link between serotonergic and endocannabinoid systems in the mechanisms underlying mood disorders caused by nicotine abstinence and suggest that these interactions are potential targets for pharmacological aid in smoking cessation.
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Affiliation(s)
- Carmen Mannucci
- Department of Clinical and Experimental Medicine and Pharmacology, Section of Pharmacology, School of Medicine, University of Messina, Via Consolare Valeria 5, Messina, Italy
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Walstab J, Rappold G, Niesler B. 5-HT(3) receptors: role in disease and target of drugs. Pharmacol Ther 2010; 128:146-69. [PMID: 20621123 DOI: 10.1016/j.pharmthera.2010.07.001] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Accepted: 06/21/2010] [Indexed: 12/19/2022]
Abstract
Serotonin type 3 (5-HT(3)) receptors are pentameric ion channels belonging to the superfamily of Cys-loop receptors. Receptor activation either leads to fast excitatory responses or modulation of neurotransmitter release depending on their neuronal localisation. 5-HT(3) receptors are known to be expressed in the central nervous system in regions involved in the vomiting reflex, processing of pain, the reward system, cognition and anxiety control. In the periphery they are present on a variety of neurons and immune cells. 5-HT(3) receptors are known to be involved in emesis, pain disorders, drug addiction, psychiatric and GI disorders. Progress in molecular genetics gives direction to personalised medical strategies for treating complex diseases such as psychiatric and functional GI disorders and unravelling individual drug responses in pharmacogenetic approaches. Here we discuss the molecular basis of 5-HT(3) receptor diversity at the DNA and protein level, of which our knowledge has greatly extended in the last decade. We also evaluate their role in health and disease and describe specific case-control studies addressing the involvement of polymorphisms of 5-HT3 subunit genes in complex disorders and responses to drugs. Furthermore, we focus on the actual state of the pharmacological knowledge concerning not only classical 5-HT(3) antagonists--the setrons--but also compounds of various substance classes targeting 5-HT(3) receptors such as anaesthetics, opioids, cannabinoids, steroids, antidepressants and antipsychotics as well as natural compounds derived from plants. This shall point to alternative treatment options modulating the 5-HT(3) receptor system and open new possibilities for drug development in the future.
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Affiliation(s)
- Jutta Walstab
- Department of Human Molecular Genetics, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
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24
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Alptekin A, Galadari S, Shuba Y, Petroianu G, Oz M. The effects of anandamide transport inhibitor AM404 on voltage-dependent calcium channels. Eur J Pharmacol 2010; 634:10-5. [PMID: 20171208 DOI: 10.1016/j.ejphar.2010.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 01/30/2010] [Accepted: 02/09/2010] [Indexed: 11/27/2022]
Abstract
The effects of anandamide transport inhibitor AM404 were investigated on depolarization-induced 45Ca2+ fluxes in transverse tubule membrane vesicles from rabbit skeletal muscle and on Ba2+ currents through L-type voltage-dependent Ca2+ channels in rat myotubes. AM404, at the concentration of 3 microM and higher, caused a significant inhibition of 45Ca2+ fluxes. Radioligand binding studies indicated that the specific binding of [3H]Isradipine to transverse tubule membranes was also inhibited significantly by AM404. In controls and in presence of 10 microM AM404, B(max) values were 51+/-6 and 27+/-5 pM/mg, and KD values were 236+/-43 and 220+/-37 pM, respectively. Inhibitory effects of AEA and arachidonic acid on 45Ca2+ flux and [3H]Isradipine binding reported in earlier studies, were also enhanced significantly in the presence of AM404. In the presence of VDM11 (1 microM), another anandamide transport inhibitor, AM404 continued to inhibit 45Ca2+ fluxes and [3H]Isradipine binding. In rat myotubes, Ca2+ currents through L-type Ca2+ channels recorded in whole-cell configuration of patch clamp technique were inhibited by AM404 in a concentration-dependent manner with an IC50 value of 3.2 microM. In conclusion, results indicate that AM404 inhibits directly the function of L-type voltage-dependent Ca2+ channels in mammalian skeletal muscles.
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Affiliation(s)
- Alp Alptekin
- Department of Anesthesiology, Yildirim Beyazit Training and Research Hospital, Ankara, 06270, Turkey
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25
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Rasmussen BA, Unterwald EM, Kim JK, Rawls SM. Methanandamide blocks amphetamine-induced behavioral sensitization in rats. Eur J Pharmacol 2009; 627:150-5. [PMID: 19879869 DOI: 10.1016/j.ejphar.2009.10.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 10/05/2009] [Accepted: 10/26/2009] [Indexed: 10/20/2022]
Abstract
Methanandamide acts at targets which modulate amphetamine-induced behaviors. Therefore, we investigated methanandamide effects on the acute hyperactivity produced by a single injection of amphetamine and behavioral sensitization induced by repeated amphetamine exposure in rats. Methanandamide (5mg/kg, i.p.) did not affect basal locomotor or stereotypical activity. Methanandamide (5mg/kg, i.p.) pretreatment did not alter the acute increase in locomotor or stereotypical activities produced by acute amphetamine (2mg/kg, i.p.). For chronic studies, rats injected with amphetamine (2mg/kg, i.p.) once daily for 3 consecutive days were then challenged with amphetamine (2mg/kg, i.p.) 5 days later. Expression of locomotor sensitization was blocked when methanandamide (5mg/kg, i.p.) was given once, just prior to amphetamine (2mg/kg, i.p.) challenge. In rats co-exposed to methanandamide (5mg/kg, i.p.) and amphetamine (2mg/kg, i.p.) on days 1-3 and then challenged with amphetamine (2mg/kg, i.p.) following 5 days of drug absence, the development of both locomotor and stereotypical sensitization was blocked. The ability of methanandamide to block amphetamine-sensitized behaviors suggests that this pharmacologically diverse lipid regulates signaling events impacted by repeated psychostimulant exposure.
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Affiliation(s)
- Bruce A Rasmussen
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, Pennsylvania 19140, USA
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26
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Lozovaya N, Min R, Tsintsadze V, Burnashev N. Dual modulation of CNS voltage-gated calcium channels by cannabinoids: Focus on CB1 receptor-independent effects. Cell Calcium 2009; 46:154-62. [PMID: 19682741 DOI: 10.1016/j.ceca.2009.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 07/18/2009] [Indexed: 01/13/2023]
Abstract
The neuromodulatory effects of cannabinoids in the central nervous system have mainly been associated with G-protein coupled cannabinoid receptor (CB1R) mediated inhibition of voltage-gated calcium channels (VGCCs). Numerous studies show, however, that cannabinoids can also modulate VGCCs independent of CB1R activation. Nevertheless, despite the fact that endocannabinoids have a nearly equal efficacy for direct and CB1R-mediated effects on VGCC, the role of the direct cannabinoid-VGCC interaction has been largely underestimated. In this review, we summarize recent studies on the modulation of different types of VGCCs by cannabinoids, highlight the evidence for and implications of the CB1R-independent modulation, and put forward the concept, that direct interaction of cannabinoids and VGCCs is as important in regulation of VGCCs function as the CB1R-mediated effects.
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Affiliation(s)
- Natalia Lozovaya
- Institut de Neurobiologie de la Méditerranée INSERM U, Marseille, France
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27
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Roberts-Crowley ML, Mitra-Ganguli T, Liu L, Rittenhouse AR. Regulation of voltage-gated Ca2+ channels by lipids. Cell Calcium 2009; 45:589-601. [PMID: 19419761 PMCID: PMC2964877 DOI: 10.1016/j.ceca.2009.03.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 03/23/2009] [Accepted: 03/24/2009] [Indexed: 11/23/2022]
Abstract
Great skepticism has surrounded the question of whether modulation of voltage-gated Ca(2+) channels (VGCCs) by the polyunsaturated free fatty acid arachidonic acid (AA) has any physiological basis. Here we synthesize findings from studies of both native and recombinant channels where micromolar concentrations of AA consistently inhibit both native and recombinant activity by stabilizing VGCCs in one or more closed states. Structural requirements for these inhibitory actions include a chain length of at least 18 carbons and multiple double bonds located near the fatty acid's carboxy terminus. Acting at a second site, AA increases the rate of VGCC activation kinetics, and in Ca(V)2.2 channels, increases current amplitude. We present evidence that phosphatidylinositol 4,5-bisphosphate (PIP(2)), a palmitoylated accessory subunit (beta(2a)) of VGCCs and AA appear to have overlapping sites of action giving rise to complex channel behavior. Their actions converge in a physiologically relevant manner during muscarinic modulation of VGCCs. We speculate that M(1) muscarinic receptors may stimulate multiple lipases to break down the PIP(2) associated with VGCCs and leave PIP(2)'s freed fatty acid tails bound to the channels to confer modulation. This unexpectedly simple scheme gives rise to unanticipated predictions and redirects thinking about lipid regulation of VGCCs.
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Affiliation(s)
- Mandy L. Roberts-Crowley
- Program in Neuroscience, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
| | - Tora Mitra-Ganguli
- Program in Neuroscience, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
| | - Liwang Liu
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
| | - Ann R. Rittenhouse
- Program in Neuroscience, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Ave North, Worcester, MA 01655 USA
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28
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Butt C, Alptekin A, Shippenberg T, Oz M. Endogenous cannabinoid anandamide inhibits nicotinic acetylcholine receptor function in mouse thalamic synaptosomes. J Neurochem 2008; 105:1235-43. [PMID: 18194436 DOI: 10.1111/j.1471-4159.2008.05225.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The effects of the endogenous cannabinoid anandamide [arachidonylethanolamide (AEA)] on the function of nicotinic acetylcholine receptor (nAChR) were investigated using the 86Rb+ efflux assay in thalamic synaptosomes. AEA reversibly inhibited 86Rb+ efflux induced by 300 microM ACh with an IC50 value of 0.9 +/- 2 microM. Pre-treatment with the cannabinoid (CB1) receptor antagonist SR141716A (1 microM), the CB2 receptor antagonist SR144528 (1 microM), or pertussis toxin (0.2 mg/mL) did not alter the inhibitory effects of AEA, suggesting that known CB receptors are not involved in AEA inhibition of nAChRs. AEA inhibition of 86Rb+ efflux was not reversed by increasing acetylcholine (ACh) concentrations. In radioligand binding studies, the specific binding of [3H]-nicotine was not altered in the presence of AEA, indicating that AEA inhibits the function of nAChR in a non-competitive manner. Neither the amidohydrolase inhibitor phenylmethylsulfonyl fluoride (0.2 mM) nor the cyclooxygenase inhibitor, indomethacin, (5 microM) affected AEA inhibition of nAChRs, suggesting that the effect of AEA is not mediated by its metabolic products. Importantly, the extent of AEA inhibition of 86Rb+ efflux was significantly attenuated by the absence of 1% fatty acid free bovine serum albumin pre-treatment, supporting previous findings that fatty acid-like compounds modulate the activity of nAChRs. Collectively, the results indicate that AEA inhibits the function of nAChRs in thalamic synaptosomes via a CB-independent mechanism and that the background activity of these receptors is affected by fatty acids and AEA.
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Affiliation(s)
- Christopher Butt
- Neuroscience Discovery, Martek Biosciences, Boulder, Colorado, USA
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29
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Jackson SN, Singhal SK, Woods AS, Morales M, Shippenberg T, Zhang L, Oz M. Volatile anesthetics and endogenous cannabinoid anandamide have additive and independent inhibitory effects on alpha(7)-nicotinic acetylcholine receptor-mediated responses in Xenopus oocytes. Eur J Pharmacol 2007; 582:42-51. [PMID: 18242598 DOI: 10.1016/j.ejphar.2007.12.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2007] [Revised: 12/12/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
Abstract
In earlier studies, the volatile anesthetics and the endogenous cannabinoid anandamide have been shown to inhibit the function of alpha(7)-nicotinic acetylcholine receptors. In the present study, interactions between the effects of volatile anesthetics and anandamide on the function of alpha(7)-nicotinic acetylcholine receptors expressed in Xenopus oocytes were investigated using the two-electrode voltage-clamp technique. Anandamide and volatile anesthetics isoflurane and halothane inhibited currents evoked with acetylcholine (100 microM) in a reversible and concentration-dependent manner. Coapplication of anandamide and volatile anesthetics caused a significantly greater inhibition of alpha(7)-nicotinic acetylcholine receptor function than anandamide or volatile anesthetics alone. Analyses of oocytes by matrix-assisted laser desorption/ionization mass spectroscopy indicated that volatile anesthetics did not alter the lipid profile of oocytes. Results of studies with chimeric alpha(7)-nicotinic acetylcholine-5-HT(3) receptors comprised of the N-terminal domain of the alpha(7)-nicotinic acetylcholine receptor and the transmembrane and carboxyl-terminal domains of 5-HT(3) receptors suggest that while isoflurane inhibition of the alpha(7)-nicotinic acetylcholine receptor is likely to involve the N-terminal region of the receptor, the site of action for anandamide involves transmembrane and carboxyl-terminal domains of the receptors. These data indicate that endocannabinoids and isoflurane have additive inhibitory effects on alpha(7)-nicotinic acetylcholine receptor function through allosteric binding sites located on the distinct regions of the receptor.
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30
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Spivak CE, Lupica CR, Oz M. The Endocannabinoid Anandamide Inhibits the Function of α4β2 Nicotinic Acetylcholine Receptors. Mol Pharmacol 2007; 72:1024-32. [PMID: 17628012 DOI: 10.1124/mol.107.036939] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The effects of the endocannabinoid anandamide (arachidonylethanolamide, AEA) on the function of alpha4beta2 nicotinic acetylcholine receptors (nAChR) stably expressed in SH-EP1 cells were investigated using the whole-cell patch-clamp technique. In the concentration range of 200 nM to 2 microM, AEA significantly reduced the maximal amplitudes and increased the desensitization of acetylcholine (ACh)-induced currents. The effects of AEA could be neither replicated by the exogenous cannabinoid Delta(9)-tetrahydrocannabinol (1 microM) nor reversed by the selective CB1 receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide (SR-141716A) (1 microM). The actions of AEA were apparent when applied extracellularly but not during intracellular dialysis. Furthermore, the effects of AEA ACh currents were not altered by the calcium chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid. The onset and washout of the AEA effects required several minutes (10-30 min), but the latter was significantly decreased in the presence of lipid-free bovine serum albumin (BSA). Moreover, BSA alone increased peak ACh current amplitudes and diminished desensitization rates in naive cells, suggesting a tonic modulation of alpha4beta2 nAChR function by an endogenous AEA-like lipid. Further analysis of AEA effects on alpha4beta2 nAChR-mediated currents, using a two-stage desensitization model, indicated that the first forward rate constant leading to desensitization, k(1), increased nearly 30-fold as a linear function of the AEA concentration. In contrast, the observation that the other three rate constants were unaltered by AEA suggested that AEA raised the energy of the activated state. These results indicate that AEA directly inhibits the function of alpha4beta2 nAChRs in a CB1 receptor-independent manner.
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Affiliation(s)
- Charles E Spivak
- National Institute on Drug Abuse, Intramural Research Program, Cellular Neurobiology Branch, Electrophysiology Unit, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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31
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Breyne J, Van de Voorde J, Vanheel B. Characterization of the vasorelaxation to methanandamide in rat gastric arteries. Can J Physiol Pharmacol 2007; 84:1121-32. [PMID: 17218976 DOI: 10.1139/y06-058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present study, the relaxant effect of the cannabinoid methanandamide was explored in rat gastric arteries. Since in some vessels cannabinoids have been shown to release calcitonin gene-related peptide (CGRP) from perivascular nerves, the influence of methanandamide was compared with that of exogenous CGRP. Methanandamide and CGRP elicited concentration-dependent, endothelium-independent relaxations. Methanandamide-induced relaxations were unaffected by the CB1 receptor antagonist AM251, the CB2 receptor antagonists AM630 and SR144528, and combined pre-exposure to AM251 and SR144528. Pre-exposure to O-1918, an antagonist of a novel nonCB1/nonCB2 cannabinoid receptor, did not influence the relaxations to methanandamide. Capsaicin or capsazepine treatment slightly inhibited methanandamide-induced relaxations. Preincubation with 30 mmol/L extracellular K+ or 3 mmol/L TEA had no significant effect on the responses elicited by methanandamide, but reduced CGRP-induced relaxations. Relaxation to 10(-5) mol/L methanandamide was significantly blunted by Bay K8644 and by preincubation with nifedipine. Furthermore, 10(-5) mol/L methanandamide significantly inhibited CaCl2-induced contractions in norepinephrine-stimulated vessels previously depleted of intra- and extracellular Ca2+. Finally, preincubation with 10(-5) mol/L methanandamide almost completely abolished high K+-induced contractions. These findings suggest that the vasorelaxant action of methanandamide in rat gastric arteries is not mediated by stimulation of known cannabinoid receptors and only partly related to stimulation of TRPV1 receptors on perivascular nerves. At high concentrations, methanandamide might induce relaxation by reducing calcium entry into the smooth muscle cells.
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MESH Headings
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology
- Animals
- Arachidonic Acids/pharmacology
- Arteries/drug effects
- Arteries/metabolism
- Calcitonin Gene-Related Peptide/pharmacology
- Calcium/metabolism
- Calcium Channel Blockers/pharmacology
- Calcium Chloride/metabolism
- Dose-Response Relationship, Drug
- Female
- In Vitro Techniques
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nifedipine/pharmacology
- Potassium/metabolism
- Rats
- Rats, Wistar
- Receptors, Cannabinoid/drug effects
- Stomach/blood supply
- TRPV Cation Channels/drug effects
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Joke Breyne
- Department of Physiology and Physiopathology, Ghent University, De Pintelaan 185, B-9000 Ghent, Belgium
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32
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Oka S, Arai S, Waku K, Tokumura A, Sugiura T. Depolarization-induced Rapid Generation of 2-Arachidonoylglycerol, an Endogenous Cannabinoid Receptor Ligand, in Rat Brain Synaptosomes. ACTA ACUST UNITED AC 2007; 141:687-97. [PMID: 17339228 DOI: 10.1093/jb/mvm070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
2-arachidonoylglycerol (2-AG) is an endogenous ligand for the cannabinoid receptors with a variety of potent biological activities. In this study, we first examined the effects of potassium-induced depolarization on the level of 2-AG in rat brain synaptosomes. We found that a significant amount of 2-AG was generated in the synaptosomes following depolarization. Notably, depolarization did not affect the levels of other molecular species of monoacylglycerols. Furthermore, the level of anandamide was very low and did not change markedly following depolarization. It thus appeared that the depolarization-induced accelerated generation is a unique feature of 2-AG. We obtained evidence that phospholipase C is involved in the generation of 2-AG in depolarized synaptosomes: U73122, a phospholipase C inhibitor, markedly reduced the depolarization-induced generation of 2-AG, and the level of diacylglycerol was rapidly elevated following depolarization. A significant amount of 2-AG was released from synaptosomes upon depolarization. Interestingly, treatment of the synaptosomes with SR141716A, a CB1 receptor antagonist, augmented the release of glutamate from depolarized synaptosomes. These results strongly suggest that the endogenous ligand for the cannabinoid receptors, i.e. 2-AG, generated through increased phospholipid metabolism upon depolarization, plays an important role in attenuating glutamate release from the synaptic terminals by acting on the CB1 receptor.
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Affiliation(s)
- Saori Oka
- Faculty of Pharmaceutical Sciences, Teikyo University, Sagamihara, Kanagawa 199-0195 Japan
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33
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Pacher P, Bátkai S, Kunos G. The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacol Rev 2006; 58:389-462. [PMID: 16968947 PMCID: PMC2241751 DOI: 10.1124/pr.58.3.2] [Citation(s) in RCA: 1458] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The recent identification of cannabinoid receptors and their endogenous lipid ligands has triggered an exponential growth of studies exploring the endocannabinoid system and its regulatory functions in health and disease. Such studies have been greatly facilitated by the introduction of selective cannabinoid receptor antagonists and inhibitors of endocannabinoid metabolism and transport, as well as mice deficient in cannabinoid receptors or the endocannabinoid-degrading enzyme fatty acid amidohydrolase. In the past decade, the endocannabinoid system has been implicated in a growing number of physiological functions, both in the central and peripheral nervous systems and in peripheral organs. More importantly, modulating the activity of the endocannabinoid system turned out to hold therapeutic promise in a wide range of disparate diseases and pathological conditions, ranging from mood and anxiety disorders, movement disorders such as Parkinson's and Huntington's disease, neuropathic pain, multiple sclerosis and spinal cord injury, to cancer, atherosclerosis, myocardial infarction, stroke, hypertension, glaucoma, obesity/metabolic syndrome, and osteoporosis, to name just a few. An impediment to the development of cannabinoid medications has been the socially unacceptable psychoactive properties of plant-derived or synthetic agonists, mediated by CB(1) receptors. However, this problem does not arise when the therapeutic aim is achieved by treatment with a CB(1) receptor antagonist, such as in obesity, and may also be absent when the action of endocannabinoids is enhanced indirectly through blocking their metabolism or transport. The use of selective CB(2) receptor agonists, which lack psychoactive properties, could represent another promising avenue for certain conditions. The abuse potential of plant-derived cannabinoids may also be limited through the use of preparations with controlled composition and the careful selection of dose and route of administration. The growing number of preclinical studies and clinical trials with compounds that modulate the endocannabinoid system will probably result in novel therapeutic approaches in a number of diseases for which current treatments do not fully address the patients' need. Here, we provide a comprehensive overview on the current state of knowledge of the endocannabinoid system as a target of pharmacotherapy.
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Affiliation(s)
- Pál Pacher
- Laboratory of Physiological Studies, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Room 2S-24, Bethesda, MD 20892-9413, USA
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34
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Oz M. Receptor-independent actions of cannabinoids on cell membranes: Focus on endocannabinoids. Pharmacol Ther 2006; 111:114-44. [PMID: 16584786 DOI: 10.1016/j.pharmthera.2005.09.009] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 09/30/2005] [Indexed: 01/08/2023]
Abstract
Cannabinoids are a structurally diverse group of mostly lipophilic molecules that bind to cannabinoid receptors. In fact, endogenous cannabinoids (endocannabinoids) are a class of signaling lipids consisting of amides and esters of long-chain polyunsaturated fatty acids. They are synthesized from lipid precursors in plasma membranes via Ca(2+) or G-protein-dependent processes and exhibit cannabinoid-like actions by binding to cannabinoid receptors. However, endocannabinoids can produce effects that are not mediated by these receptors. In pharmacologically relevant concentrations, endocannabinoids modulate the functional properties of voltage-gated ion channels including Ca(2+) channels, Na(+) channels, various types of K(+) channels, and ligand-gated ion channels such as serotonin type 3, nicotinic acetylcholine, and glycine receptors. In addition, modulatory effects of endocannabinoids on other ion-transporting membrane proteins such as transient potential receptor-class channels, gap junctions and transporters for neurotransmitters have also been demonstrated. Furthermore, functional properties of G-protein-coupled receptors for different types of neurotransmitters and neuropeptides are altered by direct actions of endocannabinoids. Although the mechanisms of these effects are currently not clear, it is likely that these direct actions of endocannabinoids are due to their lipophilic structures. These findings indicate that additional molecular targets for endocannabinoids exist and that these targets may represent novel sites for cannabinoids to alter either the excitability of the neurons or the response of the neuronal systems. This review focuses on the results of recent studies indicating that beyond their receptor-mediated effects, endocannabinoids alter the functions of ion channels and other integral membrane proteins directly.
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Affiliation(s)
- Murat Oz
- National Institute on Drug Abuse, NIH/DHHS, Intramural Research Program, Cellular Neurobiology Branch, 5500 Nathan Shock Drive, Baltimore MD, 21224, USA.
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35
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Oz M, Alptekin A, Tchugunova Y, Dinc M. Effects of saturated long-chain N-acylethanolamines on voltage-dependent Ca2+ fluxes in rabbit T-tubule membranes. Arch Biochem Biophys 2005; 434:344-51. [PMID: 15639235 DOI: 10.1016/j.abb.2004.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2004] [Revised: 11/04/2004] [Indexed: 11/29/2022]
Abstract
The effects of saturated long-chain (C: 16-22) N-acylethanolamines and a series of saturated fatty acids with the same length of carbon chains were investigated on depolarization-induced (45)Ca(2+) fluxes mediated by voltage-dependent Ca(2+) channels in transverse tubule membrane vesicles from rabbit skeletal muscle. Vesicles were loaded with (45)Ca(2+) and membrane potentials were generated by establishing potassium gradients across the vesicle using the ionophore valinomycin. Arachidonoylethanolamide and docosaenoylethanolamide but not palmitoylethanolamide and stearoylethanolamide (all 10 microM) caused a significant inhibition of depolarization-induced (45)Ca(2+) fluxes and specific binding of [(3)H]Isradipine to transverse tubule membranes. On the other hand, saturated fatty acids including palmitic, stearic, arachidic, and docosanoic acids (all 10 microM) were ineffective in functional and radioligand binding experiments. Additional experiments using endocannabinoid metabolites suggested that whereas ethanolamine and arachidic acids were ineffective, arachidonoylethanolamide inhibited Ca(2+) effluxes and specific binding of [(3)H]Isradipine. Further studies indicated that only those fatty acids containing ethanolamine as a head group and having a chain length of more than 18 carbons were effective in inhibiting depolarization-induced Ca(2+) effluxes and specific binding of [(3)H]Isradipine. In conclusion, results indicate that depending on the chain length and the head group of fatty acid, N-acylethanolamines have differential effects on the function of voltage-dependent Ca(2+) channels and on the specific binding of [(3)H]Isradipine in skeletal muscle membranes.
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Affiliation(s)
- Murat Oz
- National Institute on Drug Abuse, Cellular Neurobiology Section, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
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36
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Oz M, Jackson SN, Woods AS, Morales M, Zhang L. Additive effects of endogenous cannabinoid anandamide and ethanol on alpha7-nicotinic acetylcholine receptor-mediated responses in Xenopus Oocytes. J Pharmacol Exp Ther 2005; 313:1272-80. [PMID: 15687372 DOI: 10.1124/jpet.104.081315] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The interaction between the effects of the endogenous cannabinoid receptor agonist anandamide and ethanol on the function of homomeric alpha(7)-nicotinic acetylcholine (nACh) receptors expressed in Xenopus oocytes were investigated using the two-electrode voltage-clamp technique. Anandamide and ethanol reversibly inhibited currents evoked with 100 microM acetylcholine in a concentration-dependent manner. Coapplication of anandamide and ethanol caused a significantly greater inhibition of alpha(7)-nACh receptor function than anandamide or ethanol alone. The IC(50) value of 238 +/- 34 nM for anandamide inhibition decreased significantly to 104 +/- 23 nM in the presence of 30 mM ethanol. The inhibition of alpha(7)-mediated currents by coapplication of anandamide and ethanol was not altered by phenylmethylsulfonyl fluoride, an inhibitor of anandamide hydrolyzing enzyme, or N-(4-hydroxyphenyl)-arachidonylamide, an anandamide transport inhibitor. Analysis of oocytes by matrix-assisted laser desorption/ionization technique indicated that ethanol treatment did not alter the lipid profile of oocytes, and there is negligible, if any, anandamide present in these cells. Results of studies with chimeric alpha(7)-nACh-5-HT(3) receptors comprised of the amino-terminal domain of the alpha(7)-nACh receptor and the transmembrane and carboxyl-terminal domains of 5-HT(3) receptors suggest that although ethanol inhibition of the alpha(7)-nACh receptor is likely to involve the N-terminal region of the receptor, the site of action for anandamide is located in the transmembrane and carboxyl-terminal domains of the receptors. These data indicate that endocannabinoids and ethanol potentiate each other's inhibitory effects on alpha(7)-nACh receptor function through distinct regions of the receptor.
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Affiliation(s)
- Murat Oz
- National Institute on Drug Abuse/Intramural Research Program, Cellular Neurobiology Branch, Baltimore, MD 21224, USA.
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