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Krishnan R, Kannan MS, Deshpande DA. Superoxide Anions Inhibit Intracellular Calcium Response in Porcine Airway Smooth Muscle Cells. AJP Rep 2024; 14:e162-e169. [PMID: 38784940 PMCID: PMC11115973 DOI: 10.1055/a-2318-0625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/25/2024] [Indexed: 05/25/2024] Open
Abstract
Background Superoxide anions (O 2 - ) have multiple effects on pulmonary parenchyma altering cell proliferation, cellular metabolism, and airway smooth muscle (ASM) contraction. Intracellular calcium ([Ca 2+ ] i ) concentration plays a significant role in the regulation of ASM contraction, relaxation, proliferation, and gene expression. Objective We investigated the effects of O 2 - on agonist-stimulated changes in [Ca 2+ ] i in ASM cells. Design/Methods Fura-2 AM-loaded, freshly isolated porcine ASM (PASM) cells were used to examine [Ca 2+ ] i release in response to acetylcholine (ACh), histamine, endothelin, caffeine, and thapsigargin (TPG) in the presence or absence of extracellular Ca 2+ . Results Exposure of PASM cells to xanthine and xanthine oxidase (X + XO) resulted in a time-dependent generation of O 2 - , inhibited by superoxide dismutase (SOD). Preincubating PASM cells with X + XO for 15- or 45-minute inhibited net [Ca 2+ ] i responses to ACh, histamine, caffeine, and TPG compared with control cells. Pretreating PASM cells with SOD for 30 minutes mitigated the inhibitory effect of X + XO treatment on ACh-induced Ca 2+ elevation suggesting role of O 2 - . X + XO treatment also inhibited caffeine- and TPG-induced Ca 2+ elevation suggesting effect of O 2 - on [Ca 2+ ] i release and reuptake mechanisms. Conclusion Superoxide attenuates [Ca 2+ ] i release, reuptake, and may interfere with physiological functions of ASM cells.
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Affiliation(s)
- Ramesh Krishnan
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Mathur S. Kannan
- Departments of Pediatrics and Veterinary Pathobiology, University of Minnesota, Minneapolis, Minnesota
| | - Deepak A. Deshpande
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
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Zholos AV, Melnyk MI, Dryn DO. Molecular mechanisms of cholinergic neurotransmission in visceral smooth muscles with a focus on receptor-operated TRPC4 channel and impairment of gastrointestinal motility by general anaesthetics and anxiolytics. Neuropharmacology 2024; 242:109776. [PMID: 37913983 DOI: 10.1016/j.neuropharm.2023.109776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/13/2023] [Accepted: 10/23/2023] [Indexed: 11/03/2023]
Abstract
Acetylcholine is the primary excitatory neurotransmitter in visceral smooth muscles, wherein it binds to and activates two muscarinic receptors subtypes, M2 and M3, thus causing smooth muscle excitation and contraction. The first part of this review focuses on the types of cells involved in cholinergic neurotransmission and on the molecular mechanisms underlying acetylcholine-induced membrane depolarisation, which is the central event of excitation-contraction coupling causing Ca2+ entry via L-type Ca2+ channels and smooth muscle contraction. Studies of the muscarinic cation current in intestinal myocytes (mICAT) revealed its main molecular counterpart, receptor-operated TRPC4 channel, which is activated in synergy by both M2 and M3 receptors. M3 receptors activation is of permissive nature, while activation of M2 receptors via Gi/o proteins that are coupled to them plays a direct role in TRPC4 opening. Our understanding of signalling pathways underlying mICAT generation has vastly expanded in recent years through studies of TRPC4 gating in native cells and its regulation in heterologous cells. Recent studies using muscarinic receptor knockout have established that at low agonist concentration activation of both M2 receptor and the M2/M3 receptor complex elicits smooth muscle contraction, while at high agonist concentration M3 receptor function becomes dominant. Based on this knowledge, in the second part of this review we discuss the cellular and molecular mechanisms underlying the numerous anticholinergic effects on neuroactive drugs, in particular general anaesthetics and anxiolytics, which can significantly impair gastrointestinal motility. This article is part of the Special Issue on "Ukrainian Neuroscience".
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Affiliation(s)
- Alexander V Zholos
- Educational and Scientific Centre "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
| | - Mariia I Melnyk
- Educational and Scientific Centre "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine; A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Dariia O Dryn
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
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3
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Lyu QR, Fu K. Tissue-specific Cre driver mice to study vascular diseases. Vascul Pharmacol 2023; 153:107241. [PMID: 37923099 DOI: 10.1016/j.vph.2023.107241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/07/2023]
Abstract
Vascular diseases, including atherosclerosis and abdominal aneurysms, are the primary cause of mortality and morbidity among the elderly worldwide. The life quality of patients is significantly compromised due to inadequate therapeutic approaches and limited drug targets. To expand our comprehension of vascular diseases, gene knockout (KO) mice, especially conditional knockout (cKO) mice, are widely used for investigating gene function and mechanisms of action. The Cre-loxP system is the most common method for generating cKO mice. Numerous Cre driver mice have been established to study the main cell types that compose blood vessels, including endothelial cells, smooth muscle cells, and fibroblasts. Here, we first discuss the characteristics of each layer of the arterial wall. Next, we provide an overview of the representative Cre driver mice utilized for each of the major cell types in the vessel wall and their most recent applications in vascular biology. We then go over Cre toxicity and discuss the practical methods for minimizing Cre interference in experimental outcomes. Finally, we look into the future of tissue-specific Cre drivers by introducing the revolutionary single-cell RNA sequencing and dual recombinase system.
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Affiliation(s)
- Qing Rex Lyu
- Medical Research Center, Chongqing General Hospital, Chongqing 401147, China; Chongqing Academy of Medical Sciences, Chongqing 401147, China.
| | - Kailong Fu
- Department of Traditional Chinese Medicine, Fujian Medical University Union Hospital, Fuzhou 350001, China.
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4
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Dryn DO, Melnyk MI, Bon RS, Beech DJ, Zholos AV. Pico145 inhibits TRPC4-mediated mI CAT and postprandial small intestinal motility. Biomed Pharmacother 2023; 168:115672. [PMID: 37857250 DOI: 10.1016/j.biopha.2023.115672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/21/2023] Open
Abstract
In intestinal smooth muscle cells, receptor-operated TRPC4 are responsible for the majority of muscarinic receptor cation current (mICAT), which initiates cholinergic excitation-contraction coupling. Our aim was to examine the effects of the TRPC4 inhibitor Pico145 on mICAT and Ca2+ signalling in mouse ileal myocytes, and on intestinal motility. Ileal myocytes freshly isolated from two month-old male BALB/c mice were used for patch-clamp recordings of whole-cell currents and for intracellular Ca2+ imaging using Fura-2. Functional assessment of Pico145's effects was carried out by standard in vitro tensiometry, ex vivo video recordings and in vivo postprandial intestinal transit measurements using carmine red. Carbachol (50 µM)-induced mICAT was strongly inhibited by Pico145 starting from 1 pM. The IC50 value for the inhibitory effect of Pico145 on this current evoked by intracellularly applied GTPγS (200 µM), and thus lacking desensitisation, was found to be 3.1 pM, while carbachol-induced intracellular Ca2+ rises were inhibited with IC50 of 2.7 pM. In contrast, the current activated by direct TRPC4 agonist (-)-englerin A was less sensitive to the action of Pico145 that caused only ∼43 % current inhibition at 100 pM. The inhibitory effect developed rather slowly and it was potentiated by membrane depolarisation. In functional assays, Pico145 produced concentration-dependent suppression of both spontaneous and carbachol-evoked intestinal smooth muscle contractions and delayed postprandial intestinal transit. Thus, Pico145 is a potent GI-active small-molecule which completely inhibits mICAT at picomolar concentrations and which is as effective as trpc4 gene deficiency in in vivo intestinal motility tests.
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Affiliation(s)
- Dariia O Dryn
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., Kyiv 01024, Ukraine
| | - Mariia I Melnyk
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, 4 Bogomoletz Str., Kyiv 01024, Ukraine; Educational and Scientific Centre "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, 64 Volodymyrska Str., Kyiv 01601, Ukraine
| | - Robin S Bon
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - David J Beech
- Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Alexander V Zholos
- Educational and Scientific Centre "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, 64 Volodymyrska Str., Kyiv 01601, Ukraine.
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Hibberd TJ, Ramsay S, Spencer-Merris P, Dinning PG, Zagorodnyuk VP, Spencer NJ. Circadian rhythms in colonic function. Front Physiol 2023; 14:1239278. [PMID: 37711458 PMCID: PMC10498548 DOI: 10.3389/fphys.2023.1239278] [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: 06/13/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023] Open
Abstract
A rhythmic expression of clock genes occurs within the cells of multiple organs and tissues throughout the body, termed "peripheral clocks." Peripheral clocks are subject to entrainment by a multitude of factors, many of which are directly or indirectly controlled by the light-entrainable clock located in the suprachiasmatic nucleus of the hypothalamus. Peripheral clocks occur in the gastrointestinal tract, notably the epithelia whose functions include regulation of absorption, permeability, and secretion of hormones; and in the myenteric plexus, which is the intrinsic neural network principally responsible for the coordination of muscular activity in the gut. This review focuses on the physiological circadian variation of major colonic functions and their entraining mechanisms, including colonic motility, absorption, hormone secretion, permeability, and pain signalling. Pathophysiological states such as irritable bowel syndrome and ulcerative colitis and their interactions with circadian rhythmicity are also described. Finally, the classic circadian hormone melatonin is discussed, which is expressed in the gut in greater quantities than the pineal gland, and whose exogenous use has been of therapeutic interest in treating colonic pathophysiological states, including those exacerbated by chronic circadian disruption.
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Affiliation(s)
- Timothy J. Hibberd
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Stewart Ramsay
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | | | - Phil G. Dinning
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
- Colorectal Surgical Unit, Division of Surgery, Flinders Medical Centre, Adelaide, SA, Australia
| | | | - Nick J. Spencer
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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6
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He X, Dong K, Shen J, Hu G, Mintz JD, Atawia RT, Zhao J, Chen X, Caldwell RW, Xiang M, Stepp DW, Fulton DJ, Zhou J. The Long Noncoding RNA Cardiac Mesoderm Enhancer-Associated Noncoding RNA (Carmn) Is a Critical Regulator of Gastrointestinal Smooth Muscle Contractile Function and Motility. Gastroenterology 2023; 165:71-87. [PMID: 37030336 PMCID: PMC10330198 DOI: 10.1053/j.gastro.2023.03.229] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 03/15/2023] [Accepted: 03/20/2023] [Indexed: 04/10/2023]
Abstract
BACKGROUND & AIMS Visceral smooth muscle cells (SMCs) are an integral component of the gastrointestinal (GI) tract that regulate GI motility. SMC contraction is regulated by posttranslational signaling and the state of differentiation. Impaired SMC contraction is associated with significant morbidity and mortality, but the mechanisms regulating SMC-specific contractile gene expression, including the role of long noncoding RNAs (lncRNAs), remain largely unexplored. Herein, we reveal a critical role of Carmn (cardiac mesoderm enhancer-associated noncoding RNA), an SMC-specific lncRNA, in regulating visceral SMC phenotype and contractility of the GI tract. METHODS Genotype-Tissue Expression and publicly available single-cell RNA sequencing (scRNA-seq) data sets from embryonic, adult human, and mouse GI tissues were interrogated to identify SMC-specific lncRNAs. The functional role of Carmn was investigated using novel green fluorescent protein (GFP) knock-in (KI) reporter/knock-out (KO) mice. Bulk RNA-seq and single nucleus RNA sequencing (snRNA-seq) of colonic muscularis were used to investigate underlying mechanisms. RESULTS Unbiased in silico analyses and GFP expression patterns in Carmn GFP KI mice revealed that Carmn is highly expressed in GI SMCs in humans and mice. Premature lethality was observed in global Carmn KO and inducible SMC-specific KO mice due to GI pseudo-obstruction and severe distension of the GI tract, with dysmotility in cecum and colon segments. Histology, GI transit, and muscle myography analysis revealed severe dilation, significantly delayed GI transit, and impaired GI contractility in Carmn KO vs control mice. Bulk RNA-seq of GI muscularis revealed that loss of Carmn promotes SMC phenotypic switching, as evidenced by up-regulation of extracellular matrix genes and down-regulation of SMC contractile genes, including Mylk, a key regulator of SMC contraction. snRNA-seq further revealed SMC Carmn KO not only compromised myogenic motility by reducing contractile gene expression but also impaired neurogenic motility by disrupting cell-cell connectivity in the colonic muscularis. These findings may have translational significance, because silencing CARMN in human colonic SMCs significantly attenuated contractile gene expression, including MYLK, and decreased SMC contractility. Luciferase reporter assays showed that CARMN enhances the transactivation activity of the master regulator of SMC contractile phenotype, myocardin, thereby maintaining the GI SMC myogenic program. CONCLUSIONS Our data suggest that Carmn is indispensable for maintaining GI SMC contractile function in mice and that loss of function of CARMN may contribute to human visceral myopathy. To our knowledge this is the first study showing an essential role of lncRNA in the regulation of visceral SMC phenotype.
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Affiliation(s)
- Xiangqin He
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Kunzhe Dong
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia; Immunology Center of Georgia, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Jian Shen
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Guoqing Hu
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - James D Mintz
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Reem T Atawia
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Juanjuan Zhao
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Xiuxu Chen
- Department of Pathology and Laboratory Medicine, Loyola University Health System, Maywood, Illinois
| | - Robert W Caldwell
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Meixiang Xiang
- Department of Cardiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - David W Stepp
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, Georgia; Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - David J Fulton
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia; Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Jiliang Zhou
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia.
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7
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Silic MR, Zhang G. Bioelectricity in Developmental Patterning and Size Control: Evidence and Genetically Encoded Tools in the Zebrafish Model. Cells 2023; 12:cells12081148. [PMID: 37190057 DOI: 10.3390/cells12081148] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Developmental patterning is essential for regulating cellular events such as axial patterning, segmentation, tissue formation, and organ size determination during embryogenesis. Understanding the patterning mechanisms remains a central challenge and fundamental interest in developmental biology. Ion-channel-regulated bioelectric signals have emerged as a player of the patterning mechanism, which may interact with morphogens. Evidence from multiple model organisms reveals the roles of bioelectricity in embryonic development, regeneration, and cancers. The Zebrafish model is the second most used vertebrate model, next to the mouse model. The zebrafish model has great potential for elucidating the functions of bioelectricity due to many advantages such as external development, transparent early embryogenesis, and tractable genetics. Here, we review genetic evidence from zebrafish mutants with fin-size and pigment changes related to ion channels and bioelectricity. In addition, we review the cell membrane voltage reporting and chemogenetic tools that have already been used or have great potential to be implemented in zebrafish models. Finally, new perspectives and opportunities for bioelectricity research with zebrafish are discussed.
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Affiliation(s)
- Martin R Silic
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - GuangJun Zhang
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
- Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Inflammation, Immunology and Infectious Diseases (PI4D), Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, 625 Harrison Street, West Lafayette, IN 47907, USA
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Warthi G, Faulkner JL, Doja J, Ghanam AR, Gao P, Yang AC, Slivano OJ, Barris CT, Kress TC, Zawieja SD, Griffin SH, Xie X, Ashworth A, Christie CK, Bryant WB, Kumar A, Davis MJ, Long X, Gan L, de Chantemèle EJB, Lyu Q, Miano JM. Generation and Comparative Analysis of an Itga8-CreER T2 Mouse with Preferential Activity in Vascular Smooth Muscle Cells. NATURE CARDIOVASCULAR RESEARCH 2022; 1:1084-1100. [PMID: 36424917 PMCID: PMC9681021 DOI: 10.1038/s44161-022-00162-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 09/29/2022] [Indexed: 11/12/2022]
Abstract
All current smooth muscle cell (SMC) Cre mice similarly recombine floxed alleles in vascular and visceral SMCs. Here, we present an Itga8-CreER T2 knock-in mouse and compare its activity with a Myh11-CreER T2 mouse. Both Cre drivers demonstrate equivalent recombination in vascular SMCs. However, Myh11-CreER T2 mice, but not Itga8-CreER T2 mice, display high activity in visceral SMC-containing tissues such as intestine, show early tamoxifen-independent activity, and produce high levels of CreERT2 protein. Whereas Myh11-CreER T2 -mediated knockout of serum response factor (Srf) causes a lethal intestinal phenotype precluding analysis of the vasculature, loss of Srf with Itga8-CreER T2 (Srf Itga8 ) yields viable mice with no evidence of intestinal pathology. Male and female Srf Itga8 mice exhibit vascular contractile incompetence, and angiotensin II causes elevated blood pressure in wild type, but not Srf Itga8 , male mice. These findings establish the Itga8-CreER T2 mouse as an alternative to existing SMC Cre mice for unfettered phenotyping of vascular SMCs following selective gene loss.
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Affiliation(s)
- Ganesh Warthi
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Jessica L. Faulkner
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Jaser Doja
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Amr R. Ghanam
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Pan Gao
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Allison C. Yang
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Orazio J. Slivano
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Candee T. Barris
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Taylor C. Kress
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Scott D. Zawieja
- Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212
| | - Susan H. Griffin
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Xiaoling Xie
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Alan Ashworth
- Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, 94158
| | - Christine K. Christie
- Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - William B. Bryant
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Ajay Kumar
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Michael J. Davis
- Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212
| | - Xiaochun Long
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | - Lin Gan
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
| | | | - Qing Lyu
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
- Biomedical and Health Institute, Chongqing Institute of Green and Intelligence Technology, Chongqing, China 400714
- Chongqing General Hospital, Chongqing, China 401147
| | - Joseph M. Miano
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia 30912
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Hounguè U, Villette C, Tokoudagba JM, Chaker AB, Remila L, Auger C, Heintz D, Gbaguidi FA, Schini-Kerth VB. Carissa edulis Vahl (Apocynaceae) extract, a medicinal plant of Benin pharmacopoeia, induces potent endothelium-dependent relaxation of coronary artery rings involving nitric oxide. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 105:154370. [PMID: 35977457 DOI: 10.1016/j.phymed.2022.154370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 07/14/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Hypertension is a major cardiovascular risk factor that affects most countries including those of Africa. Although Carissa edulis Vahl, Diodia scandens Sw. and Cleome gynandra L. are traditionally used in Benin as antihypertensive treatments with some efficacy mentioned by the local population, their biological activity on the cardiovascular system remains poorly studied. AIM The study investigated the vasoreactivity of the plants and assessed the underlying mechanisms using isolated arteries. STUDY DESIGN Aqueous-ethanolic extracts of aerial parts of C. edulis, D. scandens and C. gynandra were prepared by maceration before being subjected to multi-step liquid-liquid fractionation with solvents of increasing polarity. The vasoreactivity of the extracts and fractions were assessed on isolated porcine coronary artery and rat aorta using organ chambers, the role of nitric oxide (NO) using NG-nitro-L-arginine (NO synthase inhibitor), prostanoids using indomethacin (cyclooxygenases inhibitor) and endothelium-dependent hyperpolarization using TRAM-34 plus UCL 1684 (inhibitors of calcium-dependent K+ channels), and the vascular uptake of polyphenols using Neu reagent. RESULTS The aqueous-ethanolic crude extract of C. edulis (CECE) induced potent relaxations that were exclusively endothelium-dependent and more pronounced than those to D. scandens and C. gynandra. The n-butanolic fraction of C. edulis (CEBF) was more active than the cyclohexane, dichloromethane, and ethyl acetate fractions. The relaxation induced by CECE and CEBF were inhibited by NG-nitro-L-arginine and affected neither by TRAM-34 plus UCL 1684 nor by indomethacin. CEBF induced sustained endothelium-dependent relaxations for at least 60 min, and inhibited, in a concentration-dependent manner, contractions to KCl, CaCl2, U46619 and serotonin in rings with endothelium. Analysis of CEBF by LCHRMS indicated the presence of polyphenols, terpenes, and alkaloids. Exposure of coronary artery and aorta rings to CEBF caused the accumulation of polyphenols predominantly in the endothelium. CONCLUSION C. edulis leaf extract induced pronounced endothelium-dependent relaxations and inhibited contractile responses by stimulating the endothelial formation of NO. LCHRMS analysis of the most active fraction, the butanolic fraction, revealed the presence of numerous compounds including polyphenols, terpenes, and alkaloids. The polyphenols of CEBF accumulated preferentially in the endothelium of the arterial wall. Thus, these observations support the folkloric use of C. edulis in hypertension.
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Affiliation(s)
- Ursula Hounguè
- INSERM UMR 1260, Regenerative Nanomedicine, University of Strasbourg, Strasbourg, France; Medicinal Organic Chemistry Laboratory, Faculty of Health Sciences, University of Abomey-Calavi, Cotonou, Benin.
| | - Claire Villette
- CNRS, Plant Imaging and Mass Spectrometry (PIMS), IBMP, University of Strasbourg, Strasbourg, France.
| | - Jean-Marie Tokoudagba
- Medicinal Organic Chemistry Laboratory, Faculty of Health Sciences, University of Abomey-Calavi, Cotonou, Benin
| | - Ahmed B Chaker
- INSERM UMR 1260, Regenerative Nanomedicine, University of Strasbourg, Strasbourg, France
| | - Lamia Remila
- INSERM UMR 1260, Regenerative Nanomedicine, University of Strasbourg, Strasbourg, France
| | - Cyril Auger
- INSERM UMR 1260, Regenerative Nanomedicine, University of Strasbourg, Strasbourg, France.
| | - Dimitri Heintz
- CNRS, Plant Imaging and Mass Spectrometry (PIMS), IBMP, University of Strasbourg, Strasbourg, France.
| | - Fernand A Gbaguidi
- Medicinal Organic Chemistry Laboratory, Faculty of Health Sciences, University of Abomey-Calavi, Cotonou, Benin
| | - Valérie B Schini-Kerth
- INSERM UMR 1260, Regenerative Nanomedicine, University of Strasbourg, Strasbourg, France.
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10
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Reduced Function of Endothelial Nitric Oxide and Hyperpolarization in Artery Grafts with Poor Runoff. J Surg Res 2021; 270:2-11. [PMID: 34626903 DOI: 10.1016/j.jss.2021.08.031] [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: 03/24/2021] [Revised: 08/05/2021] [Accepted: 08/27/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND The endothelium regulates vascular tonus by releasing nitric oxide (endothelium-derived nitric oxide, EDNO) and hyperpolarizing factor (endothelium-derived hyperpolarizing factor, EDHF). In vein grafts with poor runoff, lack of function of these factors causes severe intimal hyperplasia. This study evaluated how the functions of EDNO and EDHF are altered in artery grafts under poor runoff conditions. MATERIALS AND METHODS The right common carotid arteries of rabbits were excised and implanted in their original positions as autogenous grafts under normal runoff conditions ("nonoccluded grafts") or poor runoff conditions ("poor runoff grafts"). Histochemical changes, acetylcholine (ACh)-induced effects on endothelium-dependent relaxation and smooth muscle cell (SMC) hyperpolarization were examined. RESULTS Both artery graft types displayed negligible intimal hyperplasia. In the absence and presence of an EDNO synthase inhibitor, ACh-induced relaxation was lower in grafts with poor runoff than in nonoccluded grafts. Furthermore, ACh-induced but not nonreceptor agonist A23187-induced SMC hyperpolarization was lower in the poor runoff graft group than in the nonoccluded graft group. CONCLUSIONS Unlike in those in vein grafts, the functions of EDNO and EDHF in autogenous carotid artery grafts under poor runoff conditions were reduced but partly maintained. In such artery grafts, intimal hyperplasia caused by surgical operation was not present. These results may explain some of the mechanisms underlying the improved patency of artery grafts compared with vein grafts.
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11
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Zhao L, Liang YT, Tian DB, Zhang RG, Huang J, Zhu YX, Zhou WL, Zhang YL. Regulation of smooth muscle contractility by the epithelium in rat tracheas: role of prostaglandin E 2 induced by the neurotransmitter acetylcholine. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:313. [PMID: 33708940 PMCID: PMC7944331 DOI: 10.21037/atm-20-5500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Previous studies have suggested the involvement of epithelium in modulating the contractility of neighboring smooth muscle cells. However, the mechanism underlying epithelium-derived relaxation in airways remains largely unclear. This study aimed to investigate the mechanism underlying epithelium-dependent smooth muscle relaxation mediated by neurotransmitters. Methods The contractile tension of Sprague-Dawley (SD) rat tracheal rings were measured using a mechanical recording system. Intracellular Ca2+ level was measured using a Ca2+ fluorescent probe Fluo-3 AM, and the fluorescence signal was recorded by a laser scanning confocal imaging system. The prostaglandin E2 (PGE2) content was measured using an enzyme-linked immunosorbent assay kit. Results We observed that the neurotransmitter acetylcholine (ACh) restrained the electric field stimulation (EFS)-induced contraction in the intact but not epithelium-denuded rat tracheal rings. After inhibiting the muscarinic ACh receptor (mAChR) or cyclooxygenase (COX), a critical enzyme in prostaglandin synthesis, the relaxant effect of ACh was attenuated. Exogenous PGE2 showed a similar inhibitory effect on the EFS-evoked contraction of tracheal rings. Moreover, ACh triggered phospholipase C (PLC)-coupled Ca2+ release from intracellular Ca2+ stores and stimulated COX-dependent PGE2 production in primary cultured rat tracheal epithelial cells. Conclusions Collectively, this study demonstrated that ACh induced rat tracheal smooth muscle relaxation by promoting PGE2 release from tracheal epithelium, which might provide valuable insights into the cross-talk among neurons, epithelial cells and neighboring smooth muscle cells in airways.
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Affiliation(s)
- Lei Zhao
- Department of Respiration, Qingyuan People's Hospital, the Sixth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.,School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yu-Ting Liang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Dong-Bo Tian
- Department of Respiration, Qingyuan People's Hospital, the Sixth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.,School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Rui-Gang Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Department of Physiology, Basic Medical School, Guangdong Medical University, Zhanjiang, China
| | - Jiehong Huang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yun-Xin Zhu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen-Liang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yi-Lin Zhang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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12
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King BF. Burnstock and the legacy of the inhibitory junction potential and P2Y1 receptors. Purinergic Signal 2020; 17:25-31. [PMID: 33125617 PMCID: PMC7954919 DOI: 10.1007/s11302-020-09747-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/13/2020] [Indexed: 12/20/2022] Open
Abstract
The synaptic event called the inhibitory junction potential (IJP) was arguably one of the more important discoveries made by Burnstock and arguably one of his finer legacies. The discovery of the IJP fundamentally changed how electromechanical coupling was visualised in gastrointestinal smooth muscle. Its discovery also set in motion the search for novel inhibitory neurotransmitters in the enteric nervous system, eventually leading to proposal that ATP or a related nucleotide was a major inhibitory transmitter. The subsequent development of purinergic signalling gave impetus to expanding the classification of surface receptors for extracellular ATP, not only in the GI tract but beyond, and then led to successive phases of medicinal chemistry as the P2 receptor field developed. Ultimately, the discovery of the IJP led to the successful cloning of the first P2Y receptor (chick P2Y1) and expansion of mammalian ATP receptors into two classes: metabotropic P2Y receptors (encompassing P2Y1, P2Y2, P2Y4, P2Y6, P2Y11–14 receptors) and ionotropic P2X receptors (encompassing homomeric P2X1–P2X7 receptors). Here, the causal relationship between the IJP and P2Y1 is explored, setting out the milestones reached and achievements made by Burnstock and his colleagues.
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Affiliation(s)
- Brian F King
- Research Department of Neuroscience, Pharmacology & Physiology (NPP), University College London (UCL), Gower Street, London, WC1E 6BT, UK.
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13
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Kushch MM, Kushch LL, Fesenko IA, Miroshnikova OS, Matsenko OV. Microscopic features of lamina muscularis mucosae of the goose gut. REGULATORY MECHANISMS IN BIOSYSTEMS 2019. [DOI: 10.15421/021957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The aim of work was to determine the features of the microscopic structure of the lamina muscularis mucosae of the goose gut during the postnatal ontogenesis. According to the review of the literature, during the characterisation of the structure of the intestinal mucosa, researchers first pay attention to the condition of the villi, crypts, epithelial layer and their morphometric parameters, leaving the lamina muscularis mucosae aside. The intestinal lamina muscularis mucosae is an under-researched structure of the intestinal wall, the information on which is fragmentary and contradictory. The middle parts of the duodenum, jejunum, ileum, cecum and rectum of large grey geese of 13 age groups were investigated. The classic histological methods of staining by hematoxylin and eosin, aniline blue – orange (by Mallory), as well as azure II – eosin were used. It was established that the lamina muscularis mucosae of the goose’s small intestine is formed by two layers of unstriated muscle tissue: internal and external. In contradistinction to mammals, the thicker inner layer of the LMM has not a circular, but a longitudinal direction of cell location while by contrast the thinner outer layer is located in a circular direction. According to results of our research, the thickness of the lamina muscularis mucosae of the small intestine of the geese rapidly increased with age. The thickness of the duodenum corresponded to the value of adult geese at 60 days of age; jejunum, ileum, and rectum – at 21 days, cecum – at 7 days age. The lamina muscularis mucosae was thinnest in the duodenum, and it was thickest in the ileum. The lamina muscularis mucosa of the large intestine of geese is represented by only one longitudinal layer. By contrast, the thinner outer layer is located in a circular direction. Detailed information of the microscopic structure of the lamina muscularis mucosae of the intestine of geese can be useful for specialists, both morphologists and physiologists, for analyzing the histological preparations of the intestine of birds by the action of biotic and abiotic factors, as well as a basis of comparison with such structure in other species of animals. The description of the construction of this important microscopic structure of the intestine can serve a morphological basis for elucidating its function.
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14
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Spoelstra SK, Nijhuis ER, Weijmar Schultz WCM, Georgiadis JR. Female genito-pelvic reflexes: an overview. SEXUAL AND RELATIONSHIP THERAPY 2019. [DOI: 10.1080/14681994.2018.1429593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Symen K. Spoelstra
- Department of Obstetrics and Gynecology, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
| | - Esther R. Nijhuis
- Department of Obstetrics and Gynecology, Nij Smellinghe Hospital, Drachten, The Netherlands
| | - Willibrord C. M. Weijmar Schultz
- Department of Obstetrics and Gynecology, University Medical Center, Groningen, University of Groningen, Groningen, The Netherlands
| | - Janniko R. Georgiadis
- Department of Neuroscience, Section Anatomy, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
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15
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Functional autoantibodies targeting G protein-coupled receptors in rheumatic diseases. Nat Rev Rheumatol 2017; 13:648-656. [PMID: 28855694 DOI: 10.1038/nrrheum.2017.134] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
G protein-coupled receptors (GPCRs) comprise the largest and most diverse family of integral membrane proteins that participate in different physiological processes such as the regulation of the nervous and immune systems. Besides the endogenous ligands of GPCRs, functional autoantibodies are also able to bind GPCRs to trigger or block intracellular signalling pathways, resulting in agonistic or antagonistic effects, respectively. In this Review, the effects of functional GPCR-targeting autoantibodies on the pathogenesis of autoimmune diseases, including rheumatic diseases, are discussed. Autoantibodies targeting β1 and β2 adrenergic receptors, which are expressed by cardiac and airway smooth muscle cells, respectively, have an important role in the development of asthma and cardiovascular diseases. In addition, high levels of autoantibodies against the muscarinic acetylcholine receptor M3 as well as those targeting endothelin receptor type A and type 1 angiotensin II receptor have several implications in the pathogenesis of rheumatic diseases such as Sjögren syndrome and systemic sclerosis. Expanding the knowledge of the pathophysiological roles of autoantibodies against GPCRs will shed light on the biology of these receptors and open avenues for new therapeutic approaches.
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16
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ATP-sensitive K + channels maintain resting membrane potential in interstitial cells of Cajal from the mouse colon. Eur J Pharmacol 2017; 809:98-104. [PMID: 28511870 DOI: 10.1016/j.ejphar.2017.05.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/12/2017] [Accepted: 05/12/2017] [Indexed: 11/20/2022]
Abstract
To investigate the role of ATP-sensitive K+(KATP) channels on pacemaker activity in interstitial cells of Cajal (ICC), whole-cell patch clamping, RT-PCR, and intracellular Ca2+([Ca2+]i) imaging were performed in cultured colonic ICC. Pinacidil (a K+ channel opener) hyperpolarized the membrane and inhibited the generation of pacemaker potential, and this effect was reversed by glibenclamide (a KATP channel blocker). RT-PCR showed that Kir 6.1 and SUR2B were expressed in Ano-1 positive colonic ICC. Glibenclamide depolarized the membrane and increased pacemaker potential frequency. However, 5-hydroxydecanoic acid (a mitochondrial KATP channel blocker) had no effects on pacemaker potentials. Phorbol 12-myristate 13-acetate (PMA; a protein kinase C activator) blocked the pinacidil-induced effects, and PMA alone depolarized the membrane and increased pacemaker potential frequency. Cell-permeable 8-bromo-cyclic AMP also increased pacemaker potential frequency. Recordings of spontaneous intracellular Ca2+([Ca2+]i) oscillations showed that glibenclamide increased the frequency of [Ca2+]i oscillations. In small intestinal ICC, glibenclamide alone did not alter the generation of pacemaker potentials, and Kir 6.2 and SUR2B were expressed in Ano-1 positive ICC. Therefore, KATP channels in colonic ICC are activated in resting state and play an important role in maintaining resting membrane potential.
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17
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Myers KM, Elad D. Biomechanics of the human uterus. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [PMID: 28498625 DOI: 10.1002/wsbm.1388] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/23/2017] [Accepted: 03/01/2017] [Indexed: 12/15/2022]
Abstract
The appropriate biomechanical function of the uterus is required for the execution of human reproduction. These functions range from aiding the transport of the embryo to the implantation site, to remodeling its tissue walls to host the placenta, to protecting the fetus during gestation, to contracting forcefully for a safe parturition and postpartum, to remodeling back to its nonpregnant condition to renew the cycle of menstruation. To serve these remarkably diverse functions, the uterus is optimally geared with evolving and contractile muscle and tissue layers that are cued by chemical, hormonal, electrical, and mechanical signals. The relationship between these highly active biological signaling mechanisms and uterine biomechanical function is not completely understood for normal reproductive processes and pathological conditions such as adenomyosis, endometriosis, infertility and preterm labor. Animal studies have illuminated the rich structural function of the uterus, particularly in pregnancy. In humans, medical imaging techniques in ultrasound and magnetic resonance have been combined with computational engineering techniques to characterize the uterus in vivo, and advanced experimental techniques have explored uterine function using ex vivo tissue samples. The collective evidence presented in this review gives an overall perspective on uterine biomechanics related to both its nonpregnant and pregnant function, highlighting open research topics in the field. Additionally, uterine disease and infertility are discussed in the context of tissue injury and repair processes and the role of computational modeling in uncovering etiologies of disease. WIREs Syst Biol Med 2017, 9:e1388. doi: 10.1002/wsbm.1388 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Kristin M Myers
- Department of Mechanical Engineering, Columbia University, New York, NY, USA
| | - David Elad
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.,Department of Biomedical Engineering, Columbia University, New York, NY, USA
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18
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Tabata K, Komori K, Otsuka R, Kajikuri J, Itoh T. Enhancement of Nitric Oxide Production Is Responsible for Minimal Intimal Hyperplasia of Autogenous Rabbit Arterial Grafts. Circ J 2017; 81:1222-1230. [PMID: 28381695 DOI: 10.1253/circj.cj-17-0034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Vascular endothelium induces smooth muscle cell (SMC) relaxation mainly mediated by endothelium-derived nitric oxide (EDNO) and endothelium-derived hyperpolarizing factor (EDHF). It has previously been reported that functions of these endothelium factors have been greatly impaired in vein grafts. The present study was undertaken to determine whether the functions of EDNO and EDHF might be altered in artery graft.Methods and Results:In rabbits, the right carotid artery was excised and implanted in its original position as an autogenous graft ("artery graft") and the non-operated left carotid artery served as the "control artery". Histochemical changes, acetylcholine (ACh)-induced effects on the intracellular concentration of Ca2+([Ca2+]i) in endothelial cells, endothelium-dependent SMC hyperpolarization and relaxation, and tissue cGMP content were examined on post-operative day 28. "Artery graft" displayed a minimal amount of intimal hyperplasia. When compared with the "control artery", it exhibited greater ACh-induced, endothelium-dependent relaxation, but the reverse was true when EDNO production was blocked. In the "artery graft" (vs. the "control artery"), basal cGMP content was greater, whereas the [Ca2+]iincrease in endothelial cells and the endothelium-dependent SMC-hyperpolarization induced by ACh were less. CONCLUSIONS It is suggested that the [Ca2+]i-independent EDNO production covers the loss of function of endothelium-dependent SMC hyperpolarization and minimizes intimal hyperplasia caused by surgical operation in autogenous carotid artery graft.
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Affiliation(s)
- Koki Tabata
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University.,Division of Vascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine
| | - Kimihiro Komori
- Division of Vascular Surgery, Department of Surgery, Nagoya University Graduate School of Medicine
| | - Ryo Otsuka
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University
| | - Junko Kajikuri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University
| | - Takeo Itoh
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University
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19
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Ogiwara K, Ohya S, Suzuki Y, Yamamura H, Imaizumi Y. Up-Regulation of the Voltage-Gated K V2.1 K + Channel in the Renal Arterial Myocytes of Dahl Salt-Sensitive Hypertensive Rats. Biol Pharm Bull 2017; 40:1468-1474. [DOI: 10.1248/bpb.b17-00289] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kazunobu Ogiwara
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Susumu Ohya
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
- Department of Pharmacology, Kyoto Pharmaceutical University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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20
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Species-Related Differences in the Properties of TRPC4 Channels in Intestinal Myocytes of Rodents. NEUROPHYSIOLOGY+ 2016. [DOI: 10.1007/s11062-016-9592-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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21
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Steinbach SK, Husain M. Vascular smooth muscle cell differentiation from human stem/progenitor cells. Methods 2015; 101:85-92. [PMID: 26678794 DOI: 10.1016/j.ymeth.2015.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 12/03/2015] [Accepted: 12/07/2015] [Indexed: 01/16/2023] Open
Abstract
Transplantation of vascular smooth muscle cells (VSMCs) is a promising cellular therapy to promote angiogenesis and wound healing. However, VSMCs are derived from diverse embryonic sources which may influence their role in the development of vascular disease and in its therapeutic modulation. Despite progress in understanding the mechanisms of VSMC differentiation, there remains a shortage of robust methods for generating lineage-specific VSMCs from pluripotent and adult stem/progenitor cells in serum-free conditions. Here we describe a method for differentiating pluripotent stem cells, such as embryonic and induced pluripotent stem cells, as well as skin-derived precursors, into lateral plate-derived VSMCs including 'coronary-like' VSMCs and neural crest-derived VSMC, respectively. We believe this approach will have broad applications in modeling origin-specific disease vulnerability and in developing personalized cell-based vascular grafts for regenerative medicine.
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Affiliation(s)
- Sarah K Steinbach
- McEwen Centre for Regenerative Medicine, Toronto General Research Institute, 101 College St., Toronto, Ontario M5G-1L7, Canada; Division of Experimental Therapeutics, Toronto General Research Institute, 101 College St., Toronto, Ontario M5G-1L7, Canada
| | - Mansoor Husain
- McEwen Centre for Regenerative Medicine, Toronto General Research Institute, 101 College St., Toronto, Ontario M5G-1L7, Canada; Division of Experimental Therapeutics, Toronto General Research Institute, 101 College St., Toronto, Ontario M5G-1L7, Canada; Departments of Medicine, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S-1A8, Canada; Departments of Physiology, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S-1A8, Canada; Departments of Laboratory Medicine & Pathobiology, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S-1A8, Canada; Heart and Stroke Richard Lewar Centre of Excellence, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S-1A8, Canada; Ted Rogers Centre for Heart Research, University of Toronto, 1 Kings College Circle, Toronto, Ontario M5S-1A8, Canada; Peter Munk Cardiac Centre, University Health Network, 200 Elizabeth St., Toronto, Ontario M5G-2C4, Canada.
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22
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Tanahashi Y, Wang B, Murakami Y, Unno T, Matsuyama H, Nagano H, Komori S. Inhibitory effects of SKF96365 on the activities of K(+) channels in mouse small intestinal smooth muscle cells. J Vet Med Sci 2015; 78:203-11. [PMID: 26498720 PMCID: PMC4785108 DOI: 10.1292/jvms.15-0346] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In order to investigate the effects of SKF96365 (SKF), which is a non-selective cationic channel blocker, on
K+ channel currents, we recorded currents through ATP sensitive K+ (IKATP),
voltage-gated K+ (IKv) and Ca2+ activated K+ channels
(IBK) in the absence and presence of SKF in single small intestinal myocytes of mice with
patch-clamp techniques. SKF (10 µM) reversibly abolished IKATP that was induced by
cromakalim (10 µM), which is a selective ATP sensitive K+ channel opener. These
inhibitory effects were induced in a concentration-dependent and voltage-independent manner. The 50%
inhibitory concentration (IC50) was 0.85 µM, which was obviously lower than that
reported for the muscarinic cationic current. In addition, SKF (1 µM ≈ the IC50
value in IKATP suppression) reversibly inhibited the IKv that was induced by repetitive
depolarizing pulses from −80 to 20 mV. However, the extent of the inhibitory effects was only ~30%. In
contrast, SKF (1 µM) had no significant effects on spontaneous transient IBK and
caffeine-induced IBK. These results indicated that SKF inhibited ATP sensitive K+
channels and voltage-gated K+ channels, with the ATP sensitive K+ channels being more
sensitive than the voltage-gated K+ channels. These inhibitory effects on K+ channels
should be considered when SKF is used as a cationic channel blocker.
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Affiliation(s)
- Yasuyuki Tanahashi
- Department of Animal Medical Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-Ku, Kyoto 603-8555, Japan
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Benabdallah H, Gharzouli K. Effects of flavone on the contractile activity of the circular smooth muscle of the rabbit middle colon in vitro. Eur J Pharmacol 2015; 760:20-6. [PMID: 25895637 DOI: 10.1016/j.ejphar.2015.04.007] [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: 03/03/2015] [Revised: 04/03/2015] [Accepted: 04/08/2015] [Indexed: 11/25/2022]
Abstract
The circular smooth muscles of the middle colon of the rabbit generate giant contractions of high amplitude and low frequency. Flavone, at various concentrations, reduces the giant contractions and the tonic contraction induced by 10 µM carbachol and 80 mM KCl. The contractions induced by dequalinium and tetraethylammonium are reduced by flavone (30 µM). At 100 µM, flavone decreases the contraction induced by 100 µM methylene blue and 1mM orthovanadate. These results suggest that flavone inhibit the giant contractions by (1) inhibition of voltage-dependent Ca(2+) channels, (2) activation of guanyl cyclase, (3) opening of K(+) channels and (4) inhibition of tyrosines kinases.
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Affiliation(s)
- Hassiba Benabdallah
- Department of Microbiology and Biochemistry, Faculty of Sciences, University Mohamed Boudiaf of M׳sila, Algeria.
| | - Kamel Gharzouli
- Department of Animal physiology, Faculty of Nature and Life Sciences, University Ferhat Abbes of Setif, Algeria
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24
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Yefimenko OY, Savchenko YO, Falalyeyeva TM, Beregova TV, Zholobak NM, Spivak MY, Shcherbakov OB, Bubnov RV. Nanocrystalline cerium dioxide efficacy for gastrointestinal motility: potential for prokinetic treatment and prevention in elderly. EPMA J 2015; 6:6. [PMID: 25815090 PMCID: PMC4374531 DOI: 10.1186/s13167-015-0029-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/18/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Constipation is a common condition, with prevalence after 65 years, is a major colorectal cancer risk factor. Recent works have demonstrated advances in personalized, preventive nanomedicine, leading to the construction of new materials and nanodrugs, in particular, nanocrystalline cerium dioxide (NCD), having strong antioxidative prebiotic effect. The aim of our study was to investigate the influence of NCD on motor function of the stomach and colon in vivo and contractive activity of smooth muscles in different year-old rats. METHODS We included 80 rats: 3- (weight 130-160 g, n = 40) and 24-month old (weight 390-450 g, n = 40), divided into four groups as follows: І-control group; rats of II-ІV groups were injected intragastrically one injection per day during 10 days, 3 ml of water 3 ml/kg stabilizing solution, аnd 1 mmol/ml NCD, respectively. In all animals, we recorded spontaneous and carbachol-stimulated (0.01 mg/kg) gastrointestinal tract motor activity. We used the index of motor activity (IMA), expressed in cmH2O, for characterization of the motor function. We investigated smooth muscle contraction by tenzometric method, studied the spontaneous and stimulated motility by ballonographic method. RESULTS IMA reduced by 21.1 + 0.2% (p < 0.01) in the old rats of the control group compared with the young rats. A 10-day administration of NCD increased IMA in the stomach of young rats by 9.3% (р < 0.001) vs the control group. The exposure of NCD increased the amplitude of contraction to 34.2 ± 5.4 mN (n = 10) in the stomach of old rats and increased by 32.1 ± 2.4% vs the control group (p < 0.05). NCD did not influence acetylcholine (ACh) contractions in the stomach of young rats; however, in the stomach of old rats, V nr increased by 90 ± 15.2% (р < 0.001). CONCLUSIONS The index of motor activity is decreased in old rats. Nanocrystalline cerium dioxide increased the index of motor activity in all groups of rats and also evoked a significant increase of colon contractions in old rats.
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Affiliation(s)
- Olena Yu Yefimenko
- />Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, 01601 Kyiv, Ukraine
| | - Yuliya O Savchenko
- />Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, 01601 Kyiv, Ukraine
| | - Tetyana M Falalyeyeva
- />Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, 01601 Kyiv, Ukraine
| | - Tetyana V Beregova
- />Taras Shevchenko National University of Kyiv, Volodymyrska Str., 64/13, 01601 Kyiv, Ukraine
| | - Nadiya M Zholobak
- />Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, 03680 Kyiv, Ukraine
| | - Mykola Ya Spivak
- />Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, 03680 Kyiv, Ukraine
- />LCL ‘DIAPROF’, Svitlycky Str., 35, 04123 Kyiv, Ukraine
| | - Oleksandr B Shcherbakov
- />Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, 03680 Kyiv, Ukraine
| | - Rostyslav V Bubnov
- />Zabolotny Institute of Microbiology and Virology, National Academy of Sciences of Ukraine, Zabolotny Str., 154, 03680 Kyiv, Ukraine
- />Clinical Hospital ‘Pheophania’ of State Affairs Department, Zabolotny Str., 21, 03680 Kyiv, Ukraine
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Dipeptidyl peptidase 4 inhibitor reduces intimal hyperplasia in rabbit autologous jugular vein graft under poor distal runoff. J Vasc Surg 2015; 63:1360-70. [PMID: 25656593 DOI: 10.1016/j.jvs.2014.12.048] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/17/2014] [Indexed: 01/22/2023]
Abstract
BACKGROUND Dipeptidyl peptidase 4 inhibitors are widely used in patients with type 2 diabetes mellitus to accomplish glycemic control through an increase in the blood glucagon-like peptide 1 (GLP-1) concentration. These agents also inhibit vascular inflammation (eg, in atherosclerosis). This study was undertaken to determine whether and how vildagliptin (a potent dipeptidyl peptidase 4 inhibitor) might reduce intimal hyperplasia in vein grafts. METHODS Twelve rabbits were randomly divided into two groups; one group received vildagliptin orally (10 mg/kg/d; n = 6), whereas the control group (n = 6) did not. Vildagliptin administration was started 7 days before rabbits underwent interposition reversed autologous jugular vein grafting and ended at graft harvesting (28 days after the operation). Histochemical changes in the vascular wall were examined, as were changes in the acetylcholine-induced effects on the endothelial Ca(2+) concentration ([Ca(2+)]i) and endothelium-dependent relaxation. RESULTS Under fasting conditions, vildagliptin increased the plasma GLP-1 concentration, without affecting plasma glucose or insulin. Acetylcholine induced endothelium-dependent relaxation only in the vildagliptin group, and this was blocked by the nitric oxide synthase inhibitor N(ω)-nitro-l-arginine. Acetylcholine did not modify the endothelial [Ca(2+)]i in either the control or vildagliptin group. Intimal hyperplasia was significantly less in the vildagliptin group (0.11 ± 0.02 mm, n = 5) than in the controls (0.31 ± 0.06 mm, n = 4; P < .01). CONCLUSIONS Vildagliptin increased the plasma GLP-1 concentration. It also enhanced acetylcholine-induced [Ca(2+)]i-independent endothelial nitric oxide release and reduced vein graft intimal hyperplasia, independently of any glycemic control action.
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Sanders KM, Ward SM, Koh SD. Interstitial cells: regulators of smooth muscle function. Physiol Rev 2014; 94:859-907. [PMID: 24987007 DOI: 10.1152/physrev.00037.2013] [Citation(s) in RCA: 313] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα(+) cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα(+) cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Sean M Ward
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
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Bru-Mercier G, Gullam JE, Thornton S, Blanks AM, Shmygol A. Characterization of the tissue-level Ca2+ signals in spontaneously contracting human myometrium. J Cell Mol Med 2014; 16:2990-3000. [PMID: 22947266 PMCID: PMC4393727 DOI: 10.1111/j.1582-4934.2012.01626.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 08/28/2012] [Indexed: 11/30/2022] Open
Abstract
In the labouring uterus, millions of myocytes forming the complex geometrical structure of myometrium contract in synchrony to increase intrauterine pressure, dilate the cervix and eventually expel the foetus through the birth canal. The mechanisms underlying the precise coordination of contractions in human myometrium are not completely understood. In the present study, we have characterized the spatio-temporal properties of tissue-level [Ca(2+)](i) transients in thin slices of intact human myometrium. We found that the waveform of [Ca(2+)](i) transients and isotonic contractions recorded from thin slices was similar to the waveform of isometric contractions recorded from the larger strips in traditional organ bath experiments, suggesting that the spatio-temporal information obtained from thin slices is representative of the whole tissue. By comparing the time course of [Ca(2+)](i) transients in individual cells to that recorded from the bundles of myocytes we found that the majority of myocytes produce rapidly propagating long-lasting [Ca(2+)](i) transients accompanied by contractions. We also found a small number of cells showing desynchronized [Ca(2+)](i) oscillations that did not trigger contractions. The [Ca(2+)](i) oscillations in these cells were insensitive to nifedipine, but readily inhibited by the T-type Ca(2+) channel inhibitor NNC55-0396. In conclusion, our data suggest that the spread of [Ca(2+)](i) signals in human myometrium is achieved via propagation of long-lasting action potentials. The propagation was fast when action potentials propagated along bundles of myocytes and slower when propagating between the bundles of uterine myocytes.
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Vladimirova IA, Lankin YN, Philyppov IB, Sushiy LF, Shuba YM. Frequency dependence of excitation–contraction of multicellular smooth muscle preparations: the relevance to bipolar electrosurgery. J Surg Res 2014; 186:119-25. [DOI: 10.1016/j.jss.2013.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 07/22/2013] [Accepted: 08/12/2013] [Indexed: 11/27/2022]
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Kato K, Okamura K, Hatta M, Morita H, Kajioka S, Naito S, Yamazaki J. Involvement of IP3-receptor activation in endothelin-1-induced Ca2+ influx in rat pulmonary small artery. Eur J Pharmacol 2013; 720:255-63. [DOI: 10.1016/j.ejphar.2013.09.076] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/25/2013] [Accepted: 09/13/2013] [Indexed: 11/29/2022]
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30
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Yamamura H. [Imaging analyses of ion channel-molecule functions]. Nihon Yakurigaku Zasshi 2013; 142:79-84. [PMID: 23934527 DOI: 10.1254/fpj.142.79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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Makino S, Iwata A, Seki H, Takeda S. Pre-hypertension predicts pregnancy induced hypertension and its postpartum progression. HYPERTENSION RESEARCH IN PREGNANCY 2013. [DOI: 10.14390/jsshp.1.71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Shintaro Makino
- Department of Obstetrics and Gynecology, Juntendo University
- Department of Obstetrics and Gynecology, Saitama Medical University, Saitama Medical Centre
| | - Atsushi Iwata
- Department of Obstetrics and Gynecology, Saitama Medical University, Saitama Medical Centre
| | - Hiroyuki Seki
- Department of Obstetrics and Gynecology, Saitama Medical University, Saitama Medical Centre
| | - Satoru Takeda
- Department of Obstetrics and Gynecology, Juntendo University
- Department of Obstetrics and Gynecology, Saitama Medical University, Saitama Medical Centre
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Grandič M, Bajuk BP, Sepčić K, Košorok MD, Frangež R. Effects of synthetic analogues of poly-APS on contractile response of porcine coronary arteries. Toxicol In Vitro 2012. [PMID: 23178276 DOI: 10.1016/j.tiv.2012.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
APS12-2 and APS3 are synthetic analogues of polymeric alkylpyridinium salts (poly-APS) isolated from the marine sponge Reniera sarai. The aim of the present study was to determine the possible direct contractile effects of these two synthetic molecules on coronary arteries, in order partly to explain hemodynamic and cardiotoxic effects of APS12-2 previously observed in in vivo studies and to reveal possible adverse effects on the organism in the case of their clinical use. In contrast to APS3, APS12-2 caused a concentration-dependent vascular smooth muscle contraction of isolated porcine coronary ring preparations in a concentration-range from 1.36 to 13.60μM. Lanthanum chloride (5mM) and verapamil (10μM) completely abolished the APS12-2 evoked contraction of the coronary rings. Pre-incubation with indomethacin (10μM) had no effect on the contractile responses of coronary ring preparations. These results indicate that APS12-2 contracts vascular smooth muscle in a concentration-dependent manner, due to an increase of Ca(2+) influx through the voltage-gated Ca(2+) channels. Our data show for the first time that APS12-2 induces concentration-dependent contraction of coronary ring preparations, which may contribute to the cardiotoxic effects of APS12-2, in addition to hyperkalemia.
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Affiliation(s)
- Marjana Grandič
- Institute of Physiology, Pharmacology and Toxicology, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia
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Yamamura H, Ohya S, Muraki K, Imaizumi Y. Involvement of inositol 1,4,5-trisphosphate formation in the voltage-dependent regulation of the Ca(2+) concentration in porcine coronary arterial smooth muscle cells. J Pharmacol Exp Ther 2012; 342:486-96. [PMID: 22588257 DOI: 10.1124/jpet.112.194233] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The involvement of inositol 1,4,5-trisphosphate (IP(3)) formation in the voltage-dependent regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) was examined in smooth muscle cells of the porcine coronary artery. Slow ramp depolarization from -90 to 0 mV induced progressive [Ca(2+)](i) increase. The slope was reduced or increased in the presence of Cd(2+) or (±)-1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-[trifluoromethyl]-phenyl)pyridine-3-carboxlic acid methyl ester (Bay K 8644), respectively. The decrease in [Ca(2+)](i) via the membrane hyperpolarization induced by K(+) channel openers (levcromakalim and Evans blue) under current clamp was identical to that under voltage clamp. The step hyperpolarization from -40 to -80 mV reduced [Ca(2+)](i) uniformly over the whole-cell area with a time constant of ∼10 s. The [Ca(2+)](i) at either potential was unaffected by heparin, an inhibitor of IP(3) receptors. Alternatively, [Ca(2+)](i) rapidly increased in the peripheral regions by depolarization from -80 to 0 mV and stayed at that level (∼400 nM) during a 60-s pulse. When the pipette solution contained IP(3) pathway blockers [heparin, 2-aminoethoxydiphenylborate, xestospongin C, or 1-[6-[((17β)-3-methoxyestra-1,3,5[10]-trien-17-yl)amino]hexyl]-1H-pyrrole-2,5-dione (U73122)], the peak [Ca(2+)](i) was unchanged, but the sustained [Ca(2+)](i) was gradually reduced by ∼250 nM within 30 s. In the presence of Cd(2+), a long depolarization period slightly increased the [Ca(2+)](i), which was lower than that in the presence of heparin alone. In coronary arterial myocytes, the sustained increase in the [Ca(2+)](i) during depolarization was partly caused by the Ca(2+) release mediated by the enhanced formation of IP(3). The initial [Ca(2+)](i) elevation triggered by the Ca(2+) influx though voltage-dependent Ca(2+) channels may be predominantly responsible for the activation of phospholipase C for IP(3) formation.
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Affiliation(s)
- Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori, Mizuhoku, Nagoya 467-8603, Japan
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Ragy M, Elbassuoni E. The role of nitric oxide and L-type calcium channel blocker in the contractility of rabbit ileum in vitro. J Physiol Biochem 2012; 68:521-8. [PMID: 22528554 DOI: 10.1007/s13105-012-0167-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 03/30/2012] [Indexed: 01/30/2023]
Abstract
Nitric oxide (NO) and calcium channel blockers are two agents that can affect gastrointestinal motility. The goal of this work was to study the rabbit intestinal smooth muscle contraction response to (1) sodium nitroprusside (SNP), the NO donor, and its potential mechanism of action, and (2) nifedipine, the L-type Ca(2+) channel blocker; to clarify the degree of participation by extra- and intracellular Ca(2+) in smooth muscle contraction. We used standard isometric tension and intracellular micro-electrode recordings. To record the activity of the longitudinal smooth muscle of the ileum, segments of 1.5 cm length of the ileum were suspended vertically in organ baths of Krebs solution. The mechanical activity of the isolated ileal longitudinal muscle was recorded. Different substances were added, and the changes produced on spontaneous contraction were recorded. We found that SNP produced significant decrease, while nitric oxide synthase inhibitor produced significant increase in the amplitude of spontaneous contractions. Both apamin, the Ca(2+)-dependent K(+) channel blocker, and methylene blue, the inhibitor of soluble guanylate cyclase, alone, partially decreased relaxation induced by SNP. Addition of both methylene blue and apamine together abolished the inhibitory effect produced by SNP on spontaneous contractions. Nifedipine produced significant decrease in the amplitude of spontaneous contractions. In conclusion, in longitudinal muscle of rabbit ileum, calcium channels blocker are potent inhibitors of spontaneous activity. However, both extracellular and intracellular Ca(2+) participates in the spontaneous contractions. NO also has inhibitory effect on spontaneous activity, and this effect is mediated by cGMP generation system and Ca(2+)-dependent K(+) channels.
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Affiliation(s)
- Merhan Ragy
- Faculty of Medicine, Department of Physiology, Minia University, 61111, Minia, Egypt
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Itoh T, Kajikuri J. Characteristics of the actions by which 5-HT affects electrical and mechanical activities in rabbit jugular vein. Br J Pharmacol 2012; 164:979-91. [PMID: 21449974 DOI: 10.1111/j.1476-5381.2011.01373.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND AND PURPOSE 5-HT is known to be a potent vasospasmogenic agonist in various arteries. However, in veins the vasomodulating actions of 5-HT, and the underlying mechanisms, remain to be fully clarified. Here, we characterized the actions by which 5-HT affects electrical and mechanical activities in the rabbit jugular vein. EXPERIMENTAL APPROACH Membrane potential and isometric tension were measured in endothelium-intact and -denuded preparations. Localization of 5-HT receptor subtypes was examined immunohistochemically. KEY RESULTS 5-HT induced a transient then a small, sustained smooth muscle cell hyperpolarization in endothelium-intact strips. In endothelium-denuded strips, 5-HT induced only a sustained hyperpolarization, and this was changed to a depolarization by the selective 5-HT(7) receptor inhibitor SB269970. This depolarization was inhibited by the 5-HT(2A) receptor blocker sarpogrelate. 5-HT induced a relaxation of PGF(2α) -induced contracted strips that was similar in endothelium-intact and -denuded preparations. The latter relaxation was changed to contraction by SB269970 and this contraction was inhibited by sarpogrelate. Immunoreactive responses against endothelial and smooth muscle 5-HT(2A) receptors and smooth muscle 5-HT(7) receptors were identified in the vein. The 5-HT-induced relaxation of the PGF(2α) contraction was inhibited by the cAMP-dependent protein kinase inhibitor Rp-cAMPS and by the AC inhibitor SQ22536. CONCLUSIONS AND IMPLICATIONS These results indicate that 5-HT activates both smooth muscle 5-HT(7) receptors (to produce relaxation) and smooth muscle 5-HT(2A) receptors (to produce contraction) in rabbit jugular vein. We suggest that in this particular vein, the 5-HT(2A) receptor-induced depolarization and contraction are masked by the 5-HT(7) receptor-induced responses, possibly via actions mediated by cAMP.
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Affiliation(s)
- Takeo Itoh
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Japan.
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Inoue R, Shi J, Jian Z, Imai Y. Regulation of cardiovascular TRP channel functions along the NO-cGMP-PKG axis. Expert Rev Clin Pharmacol 2012; 3:347-60. [PMID: 22111615 DOI: 10.1586/ecp.10.15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
There is growing body of evidence that nitric oxide (NO)-cGMP-PKG signaling plays a central role in negative regulation of cardiovascular (CV) responses and its disorders through suppressed Ca(2+) dynamics. Other lines of evidence also reveal the stimulatory effects of this signaling on some CV functions. Recently, transient receptor potential (TRP) channels have received much attention as non-voltage-gated Ca(2+) channels involved in CV physiology and pathophysiology. Available information suggests that these channels undergo both inhibition and activation by NO via PKG-mediated phosphorylation and S-nitrosylation, respectively, and also act as upstream regulators to promote endothelial NO production. This review summarizes the roles of NO-cGMP-PKG signaling pathway, particularly in regulating TRP channel functions with their associated physiology and pathophysiology.
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Affiliation(s)
- Ryuji Inoue
- Department of Physiology, Graduate School of Medcial Sciences, Fukuoka University, Fukuoka, Japan.
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Squecco R, Garella R, Luciani G, Francini F, Baccari MC. Muscular effects of orexin A on the mouse duodenum: mechanical and electrophysiological studies. J Physiol 2011; 589:5231-46. [PMID: 21911618 DOI: 10.1113/jphysiol.2011.214940] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Orexin A (OXA) has been reported to influence gastrointestinal motility, acting at both central and peripheral neural levels. The aim of the present study was to evaluate whether OXA also exerts direct effects on the duodenal smooth muscle. The possible mechanism of action involved was investigated by employing a combined mechanical and electrophysiological approach. Duodenal segments were mounted in organ baths for isometric recording of the mechanical activity. Ionic channel activity was recorded in current- and voltage-clamp conditions by a single microelectrode inserted in a duodenal longitudinal muscle cell. In the duodenal preparations, OXA (0.3 μM) caused a TTX-insensitive transient contraction. Nifedipine (1 μM), as well as 2-aminoethyl diphenyl borate (10 μM), reduced the amplitude and shortened the duration of the response to OXA, which was abolished by Ni(2+) (50 μM) or TEA (1 mM). Electrophysiological studies in current-clamp conditions showed that OXA caused an early depolarization, which paralleled in time the contractile response, followed by a long-lasting depolarization. Such a depolarization was triggered by activation of receptor-operated Ca(2+) channels and enhanced by activation of T- and L-type Ca(2+) channels and store-operated Ca(2+) channels and by inhibition of K(+) channels. Experiments in voltage-clamp conditions demonstrated that OXA affects not only receptor-operated Ca(2+) channels, but also the maximal conductance and kinetics of activation and inactivation of Na(+), T- and L-type Ca(2+) voltage-gated channels. The results demonstrate, for the first time, that OXA exerts direct excitatory effects on the mouse duodenal smooth muscle. Finally, this work demonstrates new findings related to the expression and kinetics of the voltage-gated channel types, as well as store-operated Ca(2+) channels.
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Affiliation(s)
- Roberta Squecco
- Dipartimento di Scienze Fisiologiche, Università di Firenze, Firenze, Italy
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Andersson KE. Mechanisms of penile erection and basis for pharmacological treatment of erectile dysfunction. Pharmacol Rev 2011; 63:811-59. [PMID: 21880989 DOI: 10.1124/pr.111.004515] [Citation(s) in RCA: 232] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Erection is basically a spinal reflex that can be initiated by recruitment of penile afferents, both autonomic and somatic, and supraspinal influences from visual, olfactory, and imaginary stimuli. Several central transmitters are involved in the erectile control. Dopamine, acetylcholine, nitric oxide (NO), and peptides, such as oxytocin and adrenocorticotropin/α-melanocyte-stimulating hormone, have a facilitatory role, whereas serotonin may be either facilitatory or inhibitory, and enkephalins are inhibitory. The balance between contractant and relaxant factors controls the degree of contraction of the smooth muscle of the corpora cavernosa (CC) and determines the functional state of the penis. Noradrenaline contracts both CC and penile vessels via stimulation of α₁-adrenoceptors. Neurogenic NO is considered the most important factor for relaxation of penile vessels and CC. The role of other mediators, released from nerves or endothelium, has not been definitely established. Erectile dysfunction (ED), defined as the "inability to achieve or maintain an erection adequate for sexual satisfaction," may have multiple causes and can be classified as psychogenic, vasculogenic or organic, neurologic, and endocrinologic. Many patients with ED respond well to the pharmacological treatments that are currently available, but there are still groups of patients in whom the response is unsatisfactory. The drugs used are able to substitute, partially or completely, the malfunctioning endogenous mechanisms that control penile erection. Most drugs have a direct action on penile tissue facilitating penile smooth muscle relaxation, including oral phosphodiesterase inhibitors and intracavernosal injections of prostaglandin E₁. Irrespective of the underlying cause, these drugs are effective in the majority of cases. Drugs with a central site of action have so far not been very successful. There is a need for therapeutic alternatives. This requires identification of new therapeutic targets and design of new approaches. Research in the field is expanding, and several promising new targets for future drugs have been identified.
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Affiliation(s)
- K-E Andersson
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, USA.
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Noorani MMZ, Noel RC, Marrelli SP. Upregulated TRPC3 and Downregulated TRPC1 Channel Expression during Hypertension is Associated with Increased Vascular Contractility in Rat. Front Physiol 2011; 2:42. [PMID: 21811471 PMCID: PMC3143733 DOI: 10.3389/fphys.2011.00042] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 07/11/2011] [Indexed: 12/11/2022] Open
Abstract
Transient receptor potential (TRP) C1 and C3 (TRPC1 and TRPC3) are expressed in vascular smooth muscle cells and are thought to be involved in vascular contractility. In the present study, we determined the effect of systemic hypertension on TRPC1/TRPC3 channel expression and vascular contractility in rat carotid artery (CA). CA were studied from male spontaneously hypertensive rats (SHR), Wistar-Kyoto (WKY), and Long Evans (LE) rats. TRPC1/3 expression was determined by RT-PCR and Western blot. TRP channel function was evaluated by whole-cell patch clamp, using UTP (60 μM) to stimulate TRPC1/3 channels. Contractions of endothelium-denuded CA segments to UTP (1-300 μM) and phenylephrine (Phe; 0.1 nM-10 μM) were measured in an isometric tension bath. TRPC1 and TRPC3 mRNA was present in CA of both WKY and SHR. Western blot demonstrated 3.1 ± 1.2 times greater TRPC3 expression and 0.5 ± 0.2 times TRPC1 in SHR versus WKY CA. Isolated CA showed potentiated contraction to UTP in the SHR versus WKY. Activation of voltage-dependent Ca(2+) channels (VDCC) in UTP-mediated constriction only occurred in SHR CA. Contraction to Phe was unaltered between WKY and SHR CA and involved equal significant VDCC activation in both groups. Patch clamp demonstrated that the UTP-stimulated current (I(utp)) was greater in SHR compared to the normotensive WKY and LE rats with peak I(utp) (at -110 mV) of -63 ± 24 pA compared to -25 ± 4 pA, respectively. We demonstrate that UTP-mediated but not Phe-mediated constrictions are potentiated in the CA during hypertension. Expression of TRPC1 is decreased whereas TRPC3 is increased in SHR CA. Interestingly, VDCC activation only contributes to UTP-mediated contraction of SHR CAs whereas it contributes substantially and equally in Phe-mediated contraction. We speculate that the alteration of TRPC channel expression in hypertension leads to greater smooth muscle depolarization, VDCC activation, and vascular contractility in the UTP (but not Phe) signaling pathway.
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Moriyama T, Tsuneyoshi I, Kanmura Y. Effects of a novel benzodiazepine derivative, JM-1232(-), on human gastroepiploic artery in vitro. J Cardiothorac Vasc Anesth 2011; 25:72-7. [PMID: 20599400 DOI: 10.1053/j.jvca.2010.03.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate the effects of JM-1232(-) on norepinephrine (10(-6) mol/L)- and high K(+) (40 mmol/L)-induced contractions in isolated human gastroepiploic arteries (GEA), and to compare them with the effects of midazolam and propofol. In addition, to investigate whether the benzodiazepine-receptor antagonist, flumazenil, or μ-opioid-receptor antagonist, naloxone, influenced the vascular effects of JM-1232(-). DESIGN An in vitro experimental study. SETTING University laboratory. PARTICIPANTS GEA segments were used from 69 patients undergoing coronary artery bypass graft surgery. MEASUREMENTS AND MAIN RESULTS JM-1232(-) produced dose-dependent relaxation effects in the rings. Although these effects of JM-1232(-) were greater than those of midazolam and propofol at high concentrations (10(-5)-10(-4) mol/L), there were no significantly different relaxation effects at the clinical concentrations of 3 × 10(-6) mol/L JM-1232(-), 3 × 10(-6) mol/L midazolam, and 1 × 10(-5) mol/L propofol. In addition, all these effects were independent of the presence of a functional endothelium. Vasorelaxation induced by JM-1232(-) on norepinephrine-preconstricted GEA was inhibited by flumazenil, but not by naloxone. CONCLUSIONS These results indicate that JM-1232(-) dose-dependently relaxes smooth muscle in human GEA, this effect being independent of the endothelium. Within the ranges of plasma concentrations achieved in clinical practice, JM-1232(-) had similar vasorelaxation effects to midazolam and propofol. JM-1232(-)-induced vasorelaxation was inhibited by flumazenil, indicating that JM-1232(-)-induced vasorelaxation occurred via peripheral benzodiazepine receptor activation in the GEA.
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Affiliation(s)
- Takahiro Moriyama
- Department of Anesthesiology and Critical Care Medicine, Kagoshima University School of Medicine, Kagoshima, Japan.
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Sugihara M, Morita H, Matsuda M, Umebayashi H, Kajioka S, Ito S, Nishida M, Inoue R, Futatsuki T, Yamazaki J, Mori Y, Inoue R, Ito Y, Abe K, Hirata M. Dual signaling pathways of arterial constriction by extracellular uridine 5'-triphosphate in the rat. J Pharmacol Sci 2011; 115:293-308. [PMID: 21350312 DOI: 10.1254/jphs.10281fp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
We investigated actions of uridine 5'-triphosphate (UTP) in rat aorta, cerebral and mesenteric arteries, and their single myocytes. UTP (≥10 µM) elicited an inward-rectifying current strongly reminiscent of activation of P2X(1) receptor, and a similar current was also induced by α,β-methylene adenosine 5'-triphosphate (ATP) (≥100 nM). UTP desensitized α,β-methylene ATP-evoked current, and vice versa. The UTP-activated current was insensitive to G-protein modulators, TRPC3 inhibitors, or TRPC3 antibody, but was sensitive to P2-receptor inhibitors or P2X(1)-receptor antibody. Both UTP (1 mM) and α,β-methylene ATP (10 µM) elicited similar conductance single channel activities. UTP (≥10 µM) provoked a dose-dependent contraction of de-endothelialized aortic ring preparation consisting of phasic and tonic components. Removal of extracellular Ca(2+) or bath-applied 2',3'-O-(2,4,6-trinitrophenyl)-ATP (TNP-ATP) (30 µM) or nifedipine (10 µM) completely inhibited the phasic contraction while only partially reducing the tonic one. The tonic contraction was almost completely abolished by additional application of thapsigargin (2 µM). Similar biphasic rises in [Ca(2+)](i) were also evoked by UTP in rat aortic myocytes. In contrast to the low expression of TRPC3, significant expression of P2X(1) receptor was detected in all arteries by RT-PCR and immunoblotting, and its localization was limited to plasma membrane of myocytes as indicated by immunohistochemistry. These results suggest that UTP dually activates P2X(1)-like and P2Y receptors, but not TRPC3.
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Affiliation(s)
- Megumi Sugihara
- Special Patient Oral Care Unit, Kyushu University Hospital, Fukuoka, Japan
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Yamamoto T, Suzuki Y, Kojima K, Suzumori N, Suzuki T. The biological investigation of prostacyclin in preeclamptic women seen reduced endothelial function. Hypertens Pregnancy 2011; 29:484-91. [PMID: 20701475 DOI: 10.3109/10641950903322873] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Our aim was to determine the biological investigation of prostacyclin in preeclamptic women seen reduced endothelial vasodilatation by non-invasive technique in vivo. METHODS Using a high resolution ultrasound transducer, diameters of brachial arteries were determined after reactive hyperemia in 15 non-pregnant, 20 normotensive pregnant and 20 preeclamptic women. The concentrations of 6-keto-prostaglandin F 1alpha (6keto-PGF 1alpha) in plasma and the concentrations of adenosine-3', 5'-cyclic monophosphate (cyclic AMP) in platelets and serum were measured among the groups. RESULTS Flow-mediated vasodilatation at 1 min after reactive hyperemia was higher in normotensive pregnant than in the non-pregnant or preeclamptic women. The plasma concentration of 6 keto-PGF 1alpha as well as the serum concentration of cyclic AMP were lower in preeclamptic than those in normotensive pregnant women. The increase in cyclic AMP in the presence of a prostacyclin analogue in platelets was seen at similar levels in all three groups. CONCLUSION From these results, the concentrations of prostacyclin in plasma and cyclic AMP in serum might be low possibly due to reduced production of prostacyclin in preeclamptic women seen reduced endothelial function.
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Affiliation(s)
- Tamao Yamamoto
- Department of Obstetrics and Gynecology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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Choi S, Sun JM, Shahi PK, Zuo DC, Kim HI, Jun JY. Capsaicin inhibits the spontaneous pacemaker activity in interstitial cells of cajal from the small intestine of mouse. J Neurogastroenterol Motil 2010; 16:265-73. [PMID: 20680165 PMCID: PMC2912119 DOI: 10.5056/jnm.2010.16.3.265] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 04/22/2010] [Accepted: 04/28/2010] [Indexed: 11/25/2022] Open
Abstract
Background/Aims Capsaicin (8-methyl-N-vanillyl-6-ninenamide), a compound found in hot peppers, has been reported to have different physiological actions on different cell types. Not much work has been done about the effect of capsaicin on the function of interstitial cells of Cajal (ICC). In the present study, we examined the action of external application of capsaicin on pacemaker activity in the cultured ICC from the small intestine of mouse. Methods We investigated the effect of capsaicin on pacemaker currents in cultured ICC from the small intestine of mouse using a whole cell patch-clamp technique and Ca2+-imaging analysis. Results When capsaicin was applied externally to the pacemaker generating ICC, it completely inhibited the pacemaker potential under current-clamp mode (I = 0) and the pacemaker current under voltage-clamp mode at a -70 mV of holding potentials. The effect of capsaicin on pacemaker activity in ICC was shown dose dependently. The effect of capsaicin was not through the transient receptor potential of the vanilloid type 1 (TRPV1) channel as capsazepine did not block the effect of capsaicin. L-NAME, an inhibitor of nitric oxide synthase, also did not block the capsaicin-induced effects. When the action of capsaicin was examined in the intracellular calcium oscillation, it completely abolished the calcium oscillation. Conclusions These results prove that the capsaicin has the inhibitory effects on the ICC which is carried out neither through TRPV channel nor the nitric oxide production. Intracellular Ca2+ was also an important target for actions of capsaicin on ICC.
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Affiliation(s)
- Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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Kito Y, Suzuki H. Properties of Rikkunshi-to (TJ-43)-induced relaxation of rat gastric fundus smooth muscles. Am J Physiol Gastrointest Liver Physiol 2010; 298:G755-63. [PMID: 20167876 DOI: 10.1152/ajpgi.00333.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The relaxant effects of Rikkunshi-to (TJ-43), a gastroprotective herbal medicine, on rat gastric fundus were investigated. Experiments were carried out using standard tension and intracellular microelectrode recording techniques. During contraction induced by enprostil (0.5 microM), a prostaglandin E(2) analog, TJ-43, produced relaxation dose dependently (0.1-5.0 mg/ml) in the rat fundic circular smooth muscle (CSM) strips. The relaxant effects of TJ-43 were not affected by tetrodotoxin or 1 H[1, 2, 4] oxadiazolo [4, 3-a] quinoxalin-1-one (10 microM), an inhibitor of soluble guanylate cyclase. TJ-43 inhibited enprostil-induced membrane depolarization. Apamin (1 microM), a blocker of small-conductance Ca(2+)-activated K(+) (SK) channel, inhibited T-43-induced membrane repolarization. TJ-43-induced relaxation was biphasic, comprising of an initial fast followed by a second slow relaxation. The fast relaxation was abolished by apamin. Application of high K(+) (29.4 mM [K(+)](o)) also abolished the fast relaxation induced by TJ-43. In diabetic Goto-Kakizaki (GK) rat fundic CSM strips, the relaxant responses of TJ-43 during enprostil-induced contraction were increased compared with control rat strips. These results indicate that TJ-43 elicited fast muscle relaxation through membrane hyperpolarization induced by the activation of SK channels; the time-dependent slow relaxation reflects an additional direct of TJ-43 on CSM in the rat gastric fundus. Because TJ-43-evoked relaxation of fundic CSM strips was more potent in diabetic GK rat than in control rat, further analysis of this herb could lead to better treatments of diabetic gastroparesis.
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Affiliation(s)
- Yoshihiko Kito
- Dept. of Physiology, Nagoya City Univ. Medical School, Mizuho-ku, Nagoya, Japan.
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Juntes P, Rebolj K, Sepčić K, Maček P, Cecilija Žužek M, Cestnik V, Frangež R. Ostreolysin induces sustained contraction of porcine coronary arteries and endothelial dysfunction in middle- and large-sized vessels. Toxicon 2009; 54:784-92. [DOI: 10.1016/j.toxicon.2009.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 06/01/2009] [Accepted: 06/03/2009] [Indexed: 01/18/2023]
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Tsvilovskyy VV, Zholos AV, Aberle T, Philipp SE, Dietrich A, Zhu MX, Birnbaumer L, Freichel M, Flockerzi V. Deletion of TRPC4 and TRPC6 in mice impairs smooth muscle contraction and intestinal motility in vivo. Gastroenterology 2009; 137:1415-24. [PMID: 19549525 PMCID: PMC2757464 DOI: 10.1053/j.gastro.2009.06.046] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2008] [Revised: 05/20/2009] [Accepted: 06/18/2009] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Downstream effects of muscarinic receptor stimulation in intestinal smooth muscle include contraction and intestinal transit. We thought to determine whether classic transient receptor potential (TRPC) channels integrate the intracellular signaling cascades evoked by the stimulated receptors and thereby contribute to the control of the membrane potential, Ca-influx, and cell responses. METHODS We created trpc4-, trpc6-, and trpc4/trpc6-gene-deficient mice and analyzed them for intestinal smooth muscle function in vitro and in vivo. RESULTS In intestinal smooth muscle cells TRPC4 forms a 55 pS cation channel and underlies more than 80% of the muscarinic receptor-induced cation current (mI(CAT)). The residual mI(CAT) depends on the expression of TRPC6, indicating that TRPC6 and TRPC4 determine mI(CAT) channel activity independent of other channel subunits. In TRPC4-deficient ileal myocytes the carbachol-induced membrane depolarizations are diminished greatly and the atropine-sensitive contraction elicited by acetylcholine release from excitatory motor neurons is reduced greatly. Additional deletion of TRPC6 aggravates these effects. Intestinal transit is slowed down in mice lacking TRPC4 and TRPC6. CONCLUSIONS In intestinal smooth muscle cells TRPC4 and TRPC6 channels are gated by muscarinic receptors and are responsible for mI(CAT). They couple muscarinic receptors to depolarization of intestinal smooth muscle cells and voltage-activated Ca(2+)-influx and contraction, and thereby accelerate small intestinal motility in vivo.
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Affiliation(s)
- Volodymyr V. Tsvilovskyy
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Alexander V. Zholos
- Centre for Vision & Vascular Science, School of Medicine, Dentistry and Biomedical Sciences, Queens’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Thomas Aberle
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Stephan E. Philipp
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Alexander Dietrich
- Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Universität Marburg, 35043 Marburg, Germany
| | - Michael X. Zhu
- Department of Neuroscience, Biochemistry, and Center for Molecular Neurobiology, The Ohio State University, Columbus OH 43210, USA
| | - Lutz Birnbaumer
- Signal Transduction and Neurobiology Laboratories, Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Marc Freichel
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421 Homburg, Germany
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Beig MI, Chandra R, Talwar A, Fahim M, Katyal A. Epileptic seizure-induced hypertension and its prevention by calcium channel blockers: a real-time study in conscious telemetered rats. Can J Physiol Pharmacol 2009; 87:572-80. [PMID: 19767881 DOI: 10.1139/y09-034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epileptic seizures are accompanied by changes in autonomic function that in turn influence the cardiovascular system (hypertension and bradyarrhythmia). We have studied possible cardioprotective activity (during the ictal state in conscious animals) of valproic acid, nifedipine, and verapamil, alone and in combination, during pentylenetetrazole (PTZ)-induced seizures. Telemetry system was used for recording EEG, blood pressure, and heart rate in conscious, freely moving rats during seizures. We observed that PTZ-induced seizures were accompanied by hypertension and bradyarrhythmia. Pretreatment with valproic acid did not block seizure-induced hypertension and bradyarrhythmia. Nifedipine alone and in combination with valproic acid blocked seizure-induced hypertension and bradyarrhythmia significantly. We also observed that pretreatment with verapamil alone and in combination with valproic acid did not block seizure-induced hypertension and bradyarrhythmia significantly. Our results suggest that pretreatment with nifedipine alone or in combination with valproic acid provides protection against seizure-induced hypertension and bradyarrhythmia.
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Affiliation(s)
- Mirza Irfan Beig
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110 007, India
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Boiko OV, Manukhin BN. The significance of extracellular Ca2+ in contractile responses of chick amnion. Russ J Dev Biol 2009. [DOI: 10.1134/s106236040904002x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Inoue R, Jian Z, Kawarabayashi Y. Mechanosensitive TRP channels in cardiovascular pathophysiology. Pharmacol Ther 2009; 123:371-85. [PMID: 19501617 DOI: 10.1016/j.pharmthera.2009.05.009] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2009] [Accepted: 05/14/2009] [Indexed: 12/22/2022]
Abstract
Transient receptor potential (TRP) proteins constitute a large non-voltage-gated cation channel superfamily, activated polymodally by various physicochemical stimuli, and are implicated in a variety of cellular functions. Known activators for TRP include not only chemical stimuli such as receptor stimulation, increased acidity and pungent/cooling agents, but temperature change and various forms of mechanical stimuli such as osmotic stress, membrane stretch, and shear force. Recent investigations have revealed that at least ten mammalian TRPs exhibit mechanosensitivity (TRPC1, 5, 6; TRPV1, 2, 4; TRPM3, 7; TRPA1; TRPP2), but the mechanisms underlying it appear considerably divergent and complex. The proposed mechanisms are associated with lipid bilayer mechanics, specialized force-transducing structures, biochemical reactions, membrane trafficking and transcriptional regulation. Many of mechanosensitive (MS)-TRP channel likely undergo multiple regulations via these mechanisms. In the cardiovascular system in which hemodynamic forces constantly operate, the impact of mechanical stress may be particularly significant. Extensive morphological and functional studies have indicated that several MS-TRP channels are expressed in cardiac muscle, vascular smooth muscle, endothelium and vasosensory neurons, each differentially contributing to cardiovascular (CV) functions. To further complexity, the recent evidence suggests that mechanical stress may synergize with neurohormonal mechanisms thereby amplifying otherwise marginal responses. Furthermore, the currently available data suggest that MS-TRP channels may be involved in CV pathophysiology such as cardiac arrhythmia, cardiac hypertrophy/myopathy, hypertension and aneurysms. This review will overview currently known mechanisms for mechanical activation/modulation of TRPs and possible connections of MS-TRP channels to CV disorders.
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Affiliation(s)
- Ryuji Inoue
- Department of Physiology, Graduate School of Medical Sciences, Fukuoka University, Nanakuma 7-45-1, Jonan-ku, Fukuoka 814-0180, Japan.
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So KY, Kim SH, Sohn HM, Choi SJ, Parajuli SP, Choi S, Yeum CH, Yoon PJ, Jun JY. Carbachol regulates pacemaker activities in cultured interstitial cells of Cajal from the mouse small intestine. Mol Cells 2009; 27:525-31. [PMID: 19466600 DOI: 10.1007/s10059-009-0076-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 03/17/2009] [Accepted: 03/24/2009] [Indexed: 11/25/2022] Open
Abstract
We studied the effect of carbachol on pacemaker currents in cultured interstitial cells of Cajal (ICC) from the mouse small intestine by muscarinic stimulation using a whole cell patch clamp technique and Ca2+-imaging. ICC generated periodic pacemaker potentials in the current-clamp mode and generated spontaneous inward pacemaker currents at a holding potential of-70 mV. Exposure to carbachol depolarized the membrane and produced tonic inward pacemaker currents with a decrease in the frequency and amplitude of the pacemaker currents. The effects of carbachol were blocked by 1-dimethyl-4-diphenylacetoxypiperidinium, a muscarinic M(3) receptor antagonist, but not by methotramine, a muscarinic M(2) receptor antagonist. Intracellular GDP-beta-S suppressed the carbachol-induced effects. Carbachol-induced effects were blocked by external Na+-free solution and by flufenamic acid, a non-selective cation channel blocker, and in the presence of thapsigargin, a Ca2+-ATPase inhibitor in the endoplasmic reticulum. However, carbachol still produced tonic inward pacemaker currents with the removal of external Ca2+. In recording of intracellular Ca2+ concentrations using fluo 3-AM dye, carbachol increased intracellular Ca2+ concentrations with increasing of Ca2+ oscillations. These results suggest that carbachol modulates the pacemaker activity of ICC through the activation of non-selective cation channels via muscarinic M(3) receptors by a G-protein dependent intracellular Ca2+ release mechanism.
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Affiliation(s)
- Keum Young So
- Department of Anesthesiology, College of Medicine, Chosun University, Gwangju 501-759, Korea
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