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Lee BH, Sideris A, Ladha KS, Johnson RL, Wu CL. Cannabis and Cannabinoids in the Perioperative Period. Anesth Analg 2024; 138:16-30. [PMID: 35551150 DOI: 10.1213/ane.0000000000006070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Cannabis use is increasingly common, and with a growing number of jurisdictions implementing legalization frameworks, it is likely that providers will encounter more patients who use cannabis. Therefore, it is important for providers to understand the implications of cannabis use and practical considerations for the perioperative period. Cannabis affects multiple organ systems and may influence intraoperative anesthesia, as well as postoperative pain management. The effects of cannabis and key anesthetic considerations are reviewed here.
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Affiliation(s)
- Bradley H Lee
- From the Department of Anesthesiology, Critical Care & Pain Management, Hospital for Special Surgery, New York, New York
- Department of Anesthesiology, Weill Cornell Medicine, New York, New York
| | - Alexandra Sideris
- From the Department of Anesthesiology, Critical Care & Pain Management, Hospital for Special Surgery, New York, New York
- Department of Anesthesiology, Weill Cornell Medicine, New York, New York
| | - Karim S Ladha
- Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada
| | - Rebecca L Johnson
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Christopher L Wu
- From the Department of Anesthesiology, Critical Care & Pain Management, Hospital for Special Surgery, New York, New York
- Department of Anesthesiology, Weill Cornell Medicine, New York, New York
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Castro-da-Silva MLRD, Farias-de-França AP, Ravazoli I, Oliveira KC, Orsi VDC, Yoshida EH, Tavares RVDS, Oshima-Franco Y. Multi targets of cannabidiol (CBD) on skeletal mammalian and avian neuromuscular preparations. Nat Prod Res 2023:1-10. [PMID: 38054804 DOI: 10.1080/14786419.2023.2290675] [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: 05/18/2023] [Accepted: 11/28/2023] [Indexed: 12/07/2023]
Abstract
Cannabidiol (CBD) has been used in diseases that affect the central nervous system. Its effects on the peripheral synapses are of great interest, since endocannabinoid receptors are expressed in muscles. CBD (0.3 mM) was analysed using mammalian and avian neuromuscular preparations, through myographic techniques in complementary protocols. Mammalian cells were examined by light microscopy while exogenous acetylcholine (40 µM) and potassium chloride (100 mM) were added into avian preparations, before and at the end of experiments. Pharmacological tools such as atropine (2 µM), polyethylene glycol (PEG 400, 20 µM), Ca2+ (1.8 mM), F55-6 (20 µg/mL), and nifedipine (1.3 mM) were assessed with CBD. In mice, CBD causes a facilitatory effect and paralysis, whereas in avian, paralysis. Concluding, CBD is responsible for activated or inhibited channels, for ACh release via muscarinic receptor modulation, and by the inhibition of nicotinic receptors leading to neuromuscular blockade, with no damage to striated muscle cells.
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Affiliation(s)
| | | | | | | | - Valéria de Campos Orsi
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Sorocaba, Brazil
| | - Edson Hideaki Yoshida
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Sorocaba, Brazil
| | | | - Yoko Oshima-Franco
- Post-Graduate Program in Pharmaceutical Sciences, University of Sorocaba (UNISO), Sorocaba, Brazil
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Machamer JB, Vazquez-Cintron EJ, Stenslik MJ, Pagarigan KT, Bradford AB, Ondeck CA, McNutt PM. Neuromuscular recovery from botulism involves multiple forms of compensatory plasticity. Front Cell Neurosci 2023; 17:1226194. [PMID: 37650071 PMCID: PMC10463753 DOI: 10.3389/fncel.2023.1226194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 07/28/2023] [Indexed: 09/01/2023] Open
Abstract
Introduction Botulinum neurotoxin (BoNT) causes neuroparalytic disease and death by blocking neuromuscular transmission. There are no specific therapies for clinical botulism and the only treatment option is supportive care until neuromuscular function spontaneously recovers, which can take weeks or months after exposure. The highly specialized neuromuscular junction (NMJ) between phrenic motor neurons and diaphragm muscle fibers is the main clinical target of BoNT. Due to the difficulty in eliciting respiratory paralysis without a high mortality rate, few studies have characterized the neurophysiological mechanisms involved in diaphragm recovery from intoxication. Here, we develop a mouse model of botulism that involves partial paralysis of respiratory muscles with low mortality rates, allowing for longitudinal analysis of recovery. Methods and results Mice challenged by systemic administration of 0.7 LD50 BoNT/A developed physiological signs of botulism, such as respiratory depression and reduced voluntary running activity, that persisted for an average of 8-12 d. Studies in isolated hemidiaphragm preparations from intoxicated mice revealed profound reductions in nerve-elicited, tetanic and twitch muscle contraction strengths that recovered to baseline 21 d after intoxication. Despite apparent functional recovery, neurophysiological parameters remained depressed for 28 d, including end plate potential (EPP) amplitude, EPP success rate, quantal content (QC), and miniature EPP (mEPP) frequency. However, QC recovered more quickly than mEPP frequency, which could explain the discrepancy between muscle function studies and neurophysiological recordings. Hypothesizing that differential modulation of voltage-gated calcium channels (VGCC) contributed to the uncoupling of QC from mEPP frequency, pharmacological inhibition studies were used to study the contributions of different VGCCs to neurophysiological function. We found that N-type VGCC and P/Q-type VGCC partially restored QC but not mEPP frequency during recovery from paralysis, potentially explaining the accelerated recovery of evoked release versus spontaneous release. We identified additional changes that presumably compensate for reduced acetylcholine release during recovery, including increased depolarization of muscle fiber resting membrane potential and increased quantal size. Discussion In addition to identifying multiple forms of compensatory plasticity that occur in response to reduced NMJ function, it is expected that insights into the molecular mechanisms involved in recovery from neuromuscular paralysis will support new host-targeted treatments for multiple neuromuscular diseases.
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Affiliation(s)
- James B. Machamer
- BASF, Research Triangle Park, NC, United States
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
| | | | - Mallory J. Stenslik
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
| | - Kathleen T. Pagarigan
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
| | - Aaron B. Bradford
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
| | - Celinia A. Ondeck
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Patrick M. McNutt
- United States Army Medical Research Institute of Chemical Defense, Gunpowder, MD, United States
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, United States
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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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Le Bacquer O, Salles J, Piscitelli F, Sanchez P, Martin V, Montaurier C, Di Marzo V, Walrand S. Alterations of the endocannabinoid system and circulating and peripheral tissue levels of endocannabinoids in sarcopenic rats. J Cachexia Sarcopenia Muscle 2022; 13:662-676. [PMID: 34854262 PMCID: PMC8818601 DOI: 10.1002/jcsm.12855] [Citation(s) in RCA: 2] [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] [Received: 03/01/2021] [Revised: 08/31/2021] [Accepted: 10/11/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Activation of the endocannabinoid system (ECS) is associated with the development of obesity and insulin resistance, and with perturbed skeletal muscle development. Age-related sarcopenia is a progressive and generalized skeletal muscle disorder involving an accelerated loss of muscle mass and function, with changes in skeletal muscle protein homeostasis due to lipid accumulation and anabolic resistance. Hence, both obesity and sarcopenia share a common set of pathophysiological alterations leading to skeletal muscle impairment. The aim of this study was to characterize how sarcopenia impacts the ECS and if these modifications were related to the loss of muscle mass and function associated with aging in rats. METHODS Six-month-old and 24-month-old male rats were used to measure the contractile properties of the plantarflexors (isometric torque-frequency relationship & concentric power-velocity relationship) and to evaluate locomotor activity, motor coordination, and voluntary gait by open field, rotarod, and catwalk tests, respectively. Levels of endocannabinoids (AEA & 2-AG) and endocannabinoid-like molecules (OEA & PEA) were measured by LCF-MS/MS in plasma, skeletal muscle, and adipose tissue, while the expression of genes coding for the ECS were investigated by quantitative reverse transcription PCR (RT-qPCR). RESULTS Sarcopenia in old rats was exemplified by a 49% decrease in hindlimb muscle mass (P < 0.01), which was associated with severe impairment of isometric torque, power, voluntary locomotor activity, motor coordination, and gait quality. Sarcopenia was associated with (1) increased 2-AG (+32%, P = 0.07) and reduced PEA and OEA levels in the plasma (-25% and -40%, respectively, P < 0.01); (2) an increased content of AEA, PEA, and OEA in subcutaneous adipose tissue (P < 0.01); and (3) a four-fold increase of 2-AG content in the soleus (P < 0.01) and a reduced OEA content in EDL (-80%, P < 0.01). These alterations were associated with profound modifications in the expression of the ECS genes in the adipose tissue and skeletal muscle. CONCLUSIONS Taken together, these findings demonstrate that circulating and peripheral tissue endocannabinoid tone are altered in sarcopenia. They also demonstrate that OEA plasma levels are associated with skeletal muscle function and loss of locomotor activity in rats, suggesting OEA could be used as a circulating biomarker for sarcopenia.
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Affiliation(s)
- Olivier Le Bacquer
- INRAE, Unité de Nutrition Humaine (UNH), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jérôme Salles
- INRAE, Unité de Nutrition Humaine (UNH), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Fabiana Piscitelli
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy
| | - Phelipe Sanchez
- INRAE, Unité de Nutrition Humaine (UNH), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Vincent Martin
- AME2P, Université Clermont Auvergne, Clermont-Ferrand, France.,Institut Universitaire de France (IUF), Paris, France
| | - Christophe Montaurier
- INRAE, Unité de Nutrition Humaine (UNH), Université Clermont Auvergne, Clermont-Ferrand, France
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, Italy.,Canada Excellence Research Chair Microbiome-Endocannabinoidome Axis in Metabolic Health, Faculty of Medicine and Faculty of Agricutural and Food Sciences, IUCPQ, INAF and Centre NUTRISS, Université Laval, Quebec City, Quebec, Canada
| | - Stéphane Walrand
- INRAE, Unité de Nutrition Humaine (UNH), Université Clermont Auvergne, Clermont-Ferrand, France.,CHU Clermont-Ferrand, Service de Nutrition Clinique, Hôpital Gabriel Montpied, Clermont-Ferrand, France
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Balezina OP, Tarasova EO, Gaydukov AE. Noncanonical Activity of Endocannabinoids and Their Receptors in Central and Peripheral Synapses. BIOCHEMISTRY (MOSCOW) 2021; 86:818-832. [PMID: 34284706 DOI: 10.1134/s0006297921070038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review focuses on new aspects of endocannabinoid functions and mechanisms of activity in central and peripheral synapses, different from the general viewpoint that endocannabinoids are retrograde signaling molecules, which inhibit neurotransmitter release by activating specific presynaptic endocannabinoid receptors CB1 and CB2. Biased agonism of the endogenous and synthetic cannabinoids as well as ability of the CB-receptors to couple not only with classical Gi-proteins, but also with Gs- and Gq-proteins and, moreover, with β-arrestins (thereby triggering additional signaling pathways in synapses) are described here in detail. Examples of noncanonical tonic activity of endocannabinoids and their receptors and their role in synaptic function are also presented. The role of endocannabinoids in short-term and long-term potentiation of neurotransmitter release in central synapses and their facilitating effect on quantal size and other parameters of acetylcholine release in mammalian neuromuscular junctions are highlighted in this review. In conclusion, it is stated that the endocannabinoid system has a wider range of various multidirectional modulating effects (both potentiating and inhibiting) on neurotransmitter release than initially recognized. Re-evaluation of the functions of endocannabinoid system with consideration of its noncanonical features will lead to better understanding of its role in the normal and pathological functioning of the nervous system and other systems of the body, which has an enormous practical value.
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Affiliation(s)
- Olga P Balezina
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia
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Tarasova EO, Khotkina NA, Gaydukov AE, Balezina OP. Spontaneous Acetylcholine Release Potentiation Induced by 2-Arachidonoylglycerol and Anandamide in Mouse Motor Synapses. ACTA ACUST UNITED AC 2021. [DOI: 10.3103/s0096392521010053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Almogi-Hazan O, Or R. Cannabis, the Endocannabinoid System and Immunity-the Journey from the Bedside to the Bench and Back. Int J Mol Sci 2020; 21:ijms21124448. [PMID: 32585801 PMCID: PMC7352399 DOI: 10.3390/ijms21124448] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022] Open
Abstract
The Cannabis plant contains numerous components, including cannabinoids and other active molecules. The phyto-cannabinoid activity is mediated by the endocannabinoid system. Cannabinoids affect the nervous system and play significant roles in the regulation of the immune system. While Cannabis is not yet registered as a drug, the potential of cannabinoid-based medicines for the treatment of various conditions has led many countries to authorize their clinical use. However, the data from basic and medical research dedicated to medical Cannabis is currently limited. A variety of pathological conditions involve dysregulation of the immune system. For example, in cancer, immune surveillance and cancer immuno-editing result in immune tolerance. On the other hand, in autoimmune diseases increased immune activity causes tissue damage. Immuno-modulating therapies can regulate the immune system and therefore the immune-regulatory properties of cannabinoids, suggest their use in the therapy of immune related disorders. In this contemporary review, we discuss the roles of the endocannabinoid system in immunity and explore the emerging data about the effects of cannabinoids on the immune response in different pathologies. In addition, we discuss the complexities of using cannabinoid-based treatments in each of these conditions.
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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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Gaydukov AE, Dzhalagoniya IZ, Tarasova EO, Balezina OP. The Participation of Endocannabinoid Receptors in the Regulation of Spontaneous Synaptic Activity at Neuromuscular Junctions of Mice. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2020. [DOI: 10.1134/s1990747819060059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Echeverria-Villalobos M, Todeschini AB, Stoicea N, Fiorda-Diaz J, Weaver T, Bergese SD. Perioperative care of cannabis users: A comprehensive review of pharmacological and anesthetic considerations. J Clin Anesth 2019; 57:41-49. [DOI: 10.1016/j.jclinane.2019.03.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/16/2019] [Accepted: 03/03/2019] [Indexed: 12/23/2022]
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Theme 7 Pre-clinical therapeutic strategies. Amyotroph Lateral Scler Frontotemporal Degener 2018; 19:217-239. [DOI: 10.1080/21678421.2018.1510574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gaydukov AE, Balezina OP. Ryanodine- and CaMKII-dependent release of endogenous CGRP induces an increase in acetylcholine quantal size in neuromuscular junctions of mice. Brain Behav 2018; 8:e01058. [PMID: 29978952 PMCID: PMC6085904 DOI: 10.1002/brb3.1058] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/29/2018] [Accepted: 06/11/2018] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE The aim of this study was to identify the mechanism responsible for an increase in miniature endplate potentials (MEPPs) amplitude, induced by ryanodine as an agonist of ryanodine receptors in mouse motor nerve terminals. METHODS Using intracellular microelectrode recordings of MEPPs and evoked endplate potentials (EPPs), the changes in spontaneous and evoked acetylcholine release in motor synapses of mouse diaphragm neuromuscular preparations were studied. RESULTS Ryanodine (0.1 μM) increased both the amplitudes of MEPPs and EPPs to a similar extent (up to 130% compared to control). The ryanodine effect was prevented by blockage of receptors of calcitonin gene-related peptide (CGRP) by a truncated peptide CGRP8-37 . Endogenous CGRP is stored in large dense-core vesicles in motor nerve terminals and may be released as a co-transmitter. The ryanodine-induced increase in MEPPs amplitude may be fully prevented by inhibition of vesicular acetylcholine transporter by vesamicol or by blocking the activity of protein kinase A with H-89, suggesting that endogenous CGRP is released in response to the activation of ryanodine receptors. Activation of CGRP receptors can, in turn, upregulate the loading of acetylcholine into synaptic vesicles, which will increase the quantal size. This new feature of endogenous CGRP activity looks similar to recently described action of exogenous CGRP in motor synapses of mice. The ryanodine effect was prevented by inhibitors of Ca/Calmodulin-dependent kinase II (CaMKII) KN-62 or KN-93. Inhibition of CaMKII did not prevent the increase in MEPPs amplitude, which was caused by exogenous CGRP. CONCLUSIONS We propose that the activity of presynaptic CaMKII is necessary for the ryanodine-stimulated release of endogenous CGRP from motor nerve terminals, but CaMKII does not participate in signaling downstream the activation of CGRP-receptors followed by quantal size increase.
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Affiliation(s)
- Alexander E Gaydukov
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia.,Department of Physiology, Russian National Research Medical University, Moscow, Russia
| | - Olga P Balezina
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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