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Verheyen M, Puschkarow M, Gnipp S, Koesling D, Peters M, Mergia E. The differential roles of the two NO-GC isoforms in adjusting airway reactivity. Am J Physiol Lung Cell Mol Physiol 2022; 323:L450-L463. [PMID: 35972838 PMCID: PMC9529264 DOI: 10.1152/ajplung.00404.2021] [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] [Indexed: 11/24/2022] Open
Abstract
The enzyme, nitric oxide-sensitive guanylyl cyclase (NO-GC), is activated by binding NO to its prosthetic heme group and catalyzes the formation of cGMP. The NO-GC is primarily known to mediate vascular smooth muscle relaxation in the lung, and inhaled NO has been successfully used as a selective pulmonary vasodilator. In comparison, NO-GC’s impact on the regulation of airway tone is less acknowledged and, most importantly, little is known about the issue that NO-GC signaling is accomplished by two isoforms: NO-GC1 and NO-GC2, implying the existence of distinct “cGMP pools.” Herein, we investigated the functional role of the NO-GC isoforms in respiration by measuring lung function parameters of isoform-specific knockout (KO) mice using noninvasive and invasive techniques. Our data revealed the participation and ongoing influence of NO-GC1-derived cGMP in the regulation of airway tone by showing that respiratory resistance was enhanced in NO-GC1-KOs and increased more pronouncedly after the challenge with the bronchoconstrictor methacholine. The tissue resistance and stiffness of NO-GC1-KOs were also higher because of narrowed airways that cause tissue distortion. Contrariwise, NO-GC2-KOs displayed reduced tissue elasticity, elastic recoil, and airway reactivity to methacholine, which did not even increase in an ovalbumin model of asthma that induced hyperresponsiveness in NO-GC1-KOs. In addition, conscious NO-GC2-KOs showed a higher breathing rate with a shorter duration of inspiration and expiration time, which remained faster even in the presence of bronchoconstrictors that slow down breathing. Thus, we provide evidence of two distinct NO/cGMP pathways in airways, accomplished by either NO-GC1 or NO-GC2, adjusting differentially the airway reactivity.
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Affiliation(s)
- Malte Verheyen
- Institute of Pharmacology and Toxicology, Ruhr University Bochum, Bochum, Germany
| | - Michelle Puschkarow
- Department of Experimental Pneumology, Ruhr University Bochum, Bochum, NRW, Germany
| | - Stefanie Gnipp
- Department of Experimental Pneumology, Ruhr University Bochum, Bochum, NRW, Germany
| | - Doris Koesling
- Institute of Pharmacology and Toxicology, Ruhr University Bochum, Bochum, Germany
| | - Marcus Peters
- Department of Molecular Immunology, Ruhr University Bochum, Bochum, NRW, Germany
| | - Evanthia Mergia
- Institute of Pharmacology and Toxicology, Ruhr University Bochum, Bochum, Germany
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2
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Taylor-Clark TE, Undem BJ. Neural control of the lower airways: Role in cough and airway inflammatory disease. HANDBOOK OF CLINICAL NEUROLOGY 2022; 188:373-391. [PMID: 35965034 PMCID: PMC10688079 DOI: 10.1016/b978-0-323-91534-2.00013-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Airway function is under constant neurophysiological control, in order to maximize airflow and gas exchange and to protect the airways from aspiration, damage, and infection. There are multiple sensory nerve subtypes, whose disparate functions provide a wide array of sensory information into the CNS. Activation of these subtypes triggers specific reflexes, including cough and alterations in autonomic efferent control of airway smooth muscle, secretory cells, and vasculature. Importantly, every aspect of these reflex arcs can be impacted and altered by local inflammation caused by chronic lung disease such as asthma, bronchitis, and infections. Excessive and inappropriate activity in sensory and autonomic nerves within the airways is thought to contribute to the morbidity and symptoms associated with lung disease.
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Affiliation(s)
- Thomas E Taylor-Clark
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States
| | - Bradley J Undem
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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3
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Jendzjowsky NG, Roy A, Iftinca M, Barioni NO, Kelly MM, Herrington BA, Visser F, Altier C, Wilson RJA. PKCε stimulation of TRPV1 orchestrates carotid body responses to asthmakines. J Physiol 2020; 599:1335-1354. [PMID: 33180962 PMCID: PMC7898719 DOI: 10.1113/jp280749] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/05/2020] [Indexed: 12/11/2022] Open
Abstract
Key points We have previously shown that carotid body stimulation by lysophosphatidic acid elicits a reflex stimulation of vagal efferent activity sufficient to cause bronchoconstriction in asthmatic rats. Here, we show that pathophysiological concentrations of asthma‐associated prototypical Th2 cytokines also stimulate the carotid bodies. Stimulation of the carotid bodies by these asthmakines involves a PKCε–transient receptor potential vanilloid 1 (TRPV1) signalling mechanism likely dependent on TRPV1 S502 and T704 phosphorylation sites. As the carotid bodies’ oxygen sensitivity is independent of PKCε–TRPV1 signalling, systemic blockade of PKCε may provide a novel therapeutic target to reduce allergen‐induced asthmatic bronchoconstriction. Consistent with the therapeutic potential of blocking the PKCε–TRPV1 pathway, systemic delivery of a PKCε‐blocking peptide suppresses asthmatic respiratory distress in response to allergen and reduces airway hyperresponsiveness to bradykinin.
Abstract The autonomic nervous system orchestrates organ‐specific, systemic and behavioural responses to inflammation. Recently, we demonstrated a vital role for lysophosphatidic acid in stimulating the primary autonomic oxygen chemoreceptors, the carotid bodies, in parasympathetic‐mediated asthmatic airway hyperresponsiveness. However, the cacophony of stimulatory factors and cellular mechanisms of carotid body activation are unknown. Therefore, we set out to determine the intracellular signalling involved in carotid body‐mediated sensing of asthmatic blood‐borne inflammatory mediators. We employed a range of in vitro and rat in situ preparations, site‐directed mutagenesis, patch‐clamp, nerve recordings and pharmacological inhibition to assess cellular signalling. We show that the carotid bodies are also sensitive to asthma‐associated prototypical Th2 cytokines which elicit sensory nerve excitation. This provides additional asthmatic ligands contributing to the previously established reflex arc resulting in efferent vagal activity and asthmatic bronchoconstriction. This novel sensing role for the carotid body is mediated by a PKCε‐dependent stimulation of transient receptor potential vanilloid 1 (TRPV1), likely via TRPV1 phosphorylation at sites T704 and S502. Importantly, carotid body oxygen sensing was unaffected by blocking either PKCε or TRPV1. Further, we demonstrate that systemic PKCε blockade reduces asthmatic respiratory distress in response to allergen and airway hyperresponsiveness. These discoveries support an inflammation‐dependent, oxygen‐independent function for the carotid body and suggest that targeting PKCε provides a novel therapeutic option to abate allergic airway disease without altering life‐saving autonomic hypoxic reflexes. We have previously shown that carotid body stimulation by lysophosphatidic acid elicits a reflex stimulation of vagal efferent activity sufficient to cause bronchoconstriction in asthmatic rats. Here, we show that pathophysiological concentrations of asthma‐associated prototypical Th2 cytokines also stimulate the carotid bodies. Stimulation of the carotid bodies by these asthmakines involves a PKCε–transient receptor potential vanilloid 1 (TRPV1) signalling mechanism likely dependent on TRPV1 S502 and T704 phosphorylation sites. As the carotid bodies’ oxygen sensitivity is independent of PKCε–TRPV1 signalling, systemic blockade of PKCε may provide a novel therapeutic target to reduce allergen‐induced asthmatic bronchoconstriction. Consistent with the therapeutic potential of blocking the PKCε–TRPV1 pathway, systemic delivery of a PKCε‐blocking peptide suppresses asthmatic respiratory distress in response to allergen and reduces airway hyperresponsiveness to bradykinin.
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Affiliation(s)
- Nicholas G Jendzjowsky
- The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Arijit Roy
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Mircea Iftinca
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Nicole O Barioni
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Margaret M Kelly
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Brittney A Herrington
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
| | - Frank Visser
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Christophe Altier
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada
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4
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Goyal M, Goel A, Singh R, Chowdhury N, Verma N, Tiwari S, Deepak KK. Circadian rhythm of airways caliber and its autonomic modulation. Chronobiol Int 2020; 37:845-855. [PMID: 32077322 DOI: 10.1080/07420528.2020.1731525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The autonomic nervous system (ANS) is one of the effector pathways for circadian variation of many physiological parameters. Autonomic tone and airways caliber have been reported to exhibit circadian variation in separate studies. A simultaneous investigation of heart rate variability (HRV) and airway caliber might ascertain how airway caliber is modulated by autonomic tone. This study was planned to identify the variations in airway caliber and autonomic function tone during a 24-hour span. A total of 56 healthy male subjects with almost similar daily routines were studied. Time domain, frequency domain and nonlinear analysis of R-R interval from 5 min electrocardiogram (ECG) was done seven times during the daytime wake span at 3-hour intervals starting at 05:00 h in the morning until 23:00 h in the night. Simultaneously peak expiratory flow rate (PEFR) was determined using a mini Wright's peak flow meter. Rhythmometric analysis was done for PEFR and HRV parameters. Significant circadian variation in low frequency (LF) and high frequency (HF) variance was identified in this group of healthy subjects. The circadian rhythm of LF variance was characterized by a gradual increase and corresponding reciprocal change in HF variance from morning until night. The LF/HF ratio and SD2/SD1 ratio reflecting sympatho-vagal balance showed low to high values from morning to evening. The acrophase of the PEFR temporal pattern is similar to that of LF power and almost opposite in phase to that of HF power. PEFR is positively correlated with LF power. The circadian rhythm of airway caliber co-varies with cardiac autonomic tone. It appears that the temporal pattern of cardiac autonomic tone precedes in time that of airways caliber, thereby suggesting the latter operates under the modulatory effect of the 24-hour pattern in sympatho-vagal balance.
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Affiliation(s)
- Manish Goyal
- Department of Physiology, All India Institute of Medical Sciences , Bhubaneswar, India
| | - Arun Goel
- Department of Physiology, All India Institute of Medical Sciences , Rishikesh, India
| | - Ruchi Singh
- Department of Physiology, All India Institute of Medical Sciences , Bhopal, India
| | - Nilotpal Chowdhury
- Department of Physiology, All India Institute of Medical Sciences , Rishikesh, India
| | - Narsingh Verma
- Department of Physiology, King George's Medical University , Lucknow, India
| | - Sunita Tiwari
- Department of Physiology, King George's Medical University , Lucknow, India
| | - Kishore Kumar Deepak
- Department of Physiology, All India Institute of Medical Sciences , Delhi, India
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5
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Lourenço LO, Ramos Lopes AC, Zavan B, Soncini R. Vagotomy influences the lung response to adrenergic agonists and muscarinic antagonists. Respir Physiol Neurobiol 2019; 274:103358. [PMID: 31811939 DOI: 10.1016/j.resp.2019.103358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/01/2022]
Abstract
Mammals airways are extensively innervated by the vagus nerve, which controls the airway diameter and bronchial tone. However, very few studies described the respiratory function and lung morphology after vagal section. In the present study, we evaluated the respiratory mechanics after aerosolization of vehicle (to obtain control values), a muscarinic agonist (methacholine), a β2-adrenergic agonist (salbutamol) or a muscarinic antagonist (ipratropium bromide) in intact (Vi) and bilaterally vagotomized (Vx) Swiss male mice. Different group was established for morphometric analyze. The total lung resistance, airway resistance, elastance, compliance, lung tissue damping, lung tissue elastance, and morphological parameters (collagen and elastic fibers) were significantly different in the Vx group compared to the Vi group. Bronchoconstrictor and bronchodilators change the respiratory function of the Vx group. In conclusion, the vagus nerve modulates the lung function in response to bronchoconstriction and bronchodilation, as well as lung architecture of mice.
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Affiliation(s)
- Luiz Otávio Lourenço
- Department of Physiology, Institute of Biomedical Science, Federal University of Alfenas, 37130-000, Alfenas, MG, Brazil
| | - Ana Carolina Ramos Lopes
- Department of Physiology, Institute of Biomedical Science, Federal University of Alfenas, 37130-000, Alfenas, MG, Brazil
| | - Bruno Zavan
- Department of Physiology, Institute of Biomedical Science, Federal University of Alfenas, 37130-000, Alfenas, MG, Brazil; Integrative Animal Biology Laboratory, Institute of Biomedical Science, Federal University of Alfenas, 37130-000, Alfenas, MG, Brazil
| | - Roseli Soncini
- Department of Physiology, Institute of Biomedical Science, Federal University of Alfenas, 37130-000, Alfenas, MG, Brazil.
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6
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Kistemaker LEM, Prakash YS. Airway Innervation and Plasticity in Asthma. Physiology (Bethesda) 2019; 34:283-298. [PMID: 31165683 PMCID: PMC6863372 DOI: 10.1152/physiol.00050.2018] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 12/22/2022] Open
Abstract
Airway nerves represent a mechanistically and therapeutically important aspect that requires better highlighting in the context of diseases such as asthma. Altered structure and function (plasticity) of afferent and efferent airway innervation can contribute to airway diseases. We describe established anatomy, current understanding of how plasticity occurs, and contributions of plasticity to asthma, focusing on target-derived growth factors (neurotrophins). Perspectives toward novel treatment strategies and future research are provided.
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Affiliation(s)
- L E M Kistemaker
- Department of Molecular Pharmacology, University of Groningen , Groningen , The Netherlands
- GRIAC Research Institute, University Medical Center Groningen, University of Groningen , Groningen , The Netherlands
| | - Y S Prakash
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic , Rochester, Minnesota
- Department of Physiology and Biomedical Engineering, Mayo Clinic , Rochester, Minnesota
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7
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Hummel JP, Mayse ML, Dimmer S, Johnson PJ. Physiologic and histopathologic effects of targeted lung denervation in an animal model. J Appl Physiol (1985) 2018; 126:67-76. [PMID: 30359539 PMCID: PMC6383645 DOI: 10.1152/japplphysiol.00565.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Parasympathetic efferent innervation of the lung is the primary source of lung acetylcholine. Inhaled long-acting anticholinergics improve lung function and symptoms in patients with chronic obstructive pulmonary disease. Targeted lung denervation (TLD), a bronchoscopic procedure intended to disrupt pulmonary parasympathetic inputs, is an experimental treatment for chronic obstructive pulmonary disease. The physiologic and histologic effects of TLD have not previously been assessed. Eleven sheep and two dogs underwent circumferential ablation of the main bronchi with simultaneous balloon surface cooling using a lung denervation system (Nuvaira, Inc., Minneapolis, MN). Changes in pulmonary air flow resistance were monitored before and following TLD. Four animals were assessed for the presence or abolishment of the sensory axon-mediated Hering-Breuer reflex before and following TLD. Six sheep were histologically evaluated 30 days post-TLD for the extent of lung denervation (axonal staining) and effect on peribronchial structures near the treatment site. No adverse clinical effects were seen in any treated animals. TLD produced a ~30% reduction in pulmonary resistance and abolished the sensory-mediated Hering-Breuer reflex. Axonal staining was consistently decreased 60% at 30 days after TLD. All treated airways exhibited 100% epithelial integrity. Damage to other peribronchial structures was minimal. Tissue 1 cm proximal and distal to the treatment was normal, and the esophagus and periesophageal vagus nerve branches were unaffected. TLD treatment effectively denervates the lung while protecting the bronchial epithelium and minimizing effects on peribronchial structures. NEW & NOTEWORTHY The feasibility of targeted lung denervation, a new minimally invasive therapy for obstructive lung disease, has been demonstrated in humans with preliminary clinical studies demonstrating improvement in symptoms, pulmonary function, and exercise capacity in patients with chronic obstructive pulmonary disease. This preclinical animal study demonstrates the ability of targeted lung denervation to disrupt vagal inputs to the lung and details its physiologic and histopathologic effects.
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Affiliation(s)
- James P Hummel
- Division of Cardiology, University of Wisconsin , Madison, Wisconsin
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8
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Khosravi M, Lin RL, Lee LY. Inhalation of electronic cigarette aerosol induces reflex bronchoconstriction by activation of vagal bronchopulmonary C-fibers. Am J Physiol Lung Cell Mol Physiol 2018; 315:L467-L475. [PMID: 29847989 PMCID: PMC6230882 DOI: 10.1152/ajplung.00137.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/23/2018] [Accepted: 05/23/2018] [Indexed: 11/22/2022] Open
Abstract
The electronic cigarette (e-cig) has been suggested as a safer alternative to tobacco cigarettes. However, the health effects of e-cigs on the airways have not been fully investigated. Nicotine, the primary chemical constituent of the e-cig aerosol, has been shown to stimulate vagal bronchopulmonary C-fiber sensory nerves, which upon activation can elicit vigorous pulmonary defense reflexes, including airway constriction. In this study, we investigated the bronchomotor response to e-cig inhalation challenge in anesthetized guinea pigs and the mechanisms involved in regulating these responses. Our results showed that delivery of a single puff of e-cig aerosol into the lung triggered immediately a transient bronchoconstriction that sustained for >2 min. The increase in airway resistance was almost completely abolished by a pretreatment with either intravenous injection of atropine or inhalation of aerosolized lidocaine, suggesting that the bronchoconstriction was elicited by cholinergic reflex mechanism and stimulation of airway sensory nerves was probably involved. Indeed, electrophysiological recording further confirmed that inhalation of e-cig aerosol exerted a pronounced stimulatory effect on vagal bronchopulmonary C-fibers. These effects on airway resistance and bronchopulmonary C-fiber activity were absent when the e-cig aerosol containing zero nicotine was inhaled, indicating a critical role of nicotine. Furthermore, a pretreatment with nicotinic acetylcholine receptor antagonists by inhalation completely prevented the airway constriction evoked by e-cig aerosol inhalation. In conclusion, inhalation of a single puff of e-cig aerosol caused a transient bronchoconstriction that was mediated through cholinergic reflex and triggered by a stimulatory effect of nicotine on vagal bronchopulmonary C-fiber afferents.
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Affiliation(s)
- M. Khosravi
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of Kentucky Medical Center, Lexington, Kentucky
| | - R. L. Lin
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky
| | - L.-Y. Lee
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky
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9
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Abstract
PURPOSE OF REVIEW To provide a fast overview about the introduction and development of anticholinergic drugs in Western medicine to their current indications particularly in asthma. RECENT FINDINGS Although short-acting muscarinic antagonists have been positioned in the last 15 years for the treatment of adults and children with moderate-to-severe acute asthma in the emergency setting (reducing the risk of hospital admissions and improving lung function), a growing body of evidence has recently emerged that positions the long-acting muscarinic anticholinergic tiotropium bromide as add-on therapy to at least inhaled corticosteroids (ICS) maintenance therapy in adults, adolescents, and children with symptomatic asthma. Thus, the addition of tiotropium bromide to ICS alone or ICS and another controller was associated with significant improvements in spirometric measures and asthma control, and a significantly decrease in the rate of asthma exacerbations. SUMMARY Short-acting muscarinic antagonists and tiotropium bromide have a well established role in the treatment of different phases of asthma. Further data are needed to provide more evidence on other selective long-acting muscarinic antagonists in addition to tiotropium as potential treatment options.
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10
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Wicher SA, Lawson KL, Jacoby DB, Fryer AD, Drake MG. Ozone-induced eosinophil recruitment to airways is altered by antigen sensitization and tumor necrosis factor- α blockade. Physiol Rep 2017; 5:e13538. [PMID: 29242307 PMCID: PMC5742702 DOI: 10.14814/phy2.13538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 10/23/2017] [Accepted: 10/23/2017] [Indexed: 01/21/2023] Open
Abstract
Ozone is an atmospheric pollutant that causes lung inflammation and airway hyperresponsiveness. Ozone's effects occur in two distinct phases that are mediated by different populations of eosinophils. In the acute phase 1 day after exposure, mature airway-resident eosinophils alter parasympathetic nerve function that results in airway hyperresponsiveness. At this time point, the severity of hyperresponsiveness correlates with the number of eosinophils in close proximity to airway nerves, but not with eosinophils in bronchoalveolar lavage. Three days later, newly divided eosinophils are recruited to airways by a tumor necrosis factor-α-dependent mechanism. These new eosinophils paradoxically attenuate ozone-induced airway hyperresponsiveness. Ozone's effects on airway tissue eosinophils and nerve-associated eosinophils 3 days after exposure are unknown. Thus, we tested ozone's effects on eosinophils in airway subepithelium and around airway nerves 1 and 3 days after ozone in nonsensitized and ovalbumin-sensitized guinea pigs with or without the tumor necrosis factor-α antagonist, etanercept, and compared changes in eosinophils with ozone-induced airway hyperresponsiveness. More eosinophils were present in small, noncartilaginous airways and along small airway nerves compared to large cartilaginous airways in all treatment groups. The number of airway and nerve-associated eosinophils were unaffected 1 day after ozone exposure, whereas significantly fewer airway eosinophils were present 3 days later. Airway and nerve-associated eosinophils were also decreased in small airways 3 days after ozone in sensitized animals. These changes were blocked by etanercept. Airway eosinophils, but not nerve-associated or bronchoalveolar lavage eosinophils correlated with airway hyperresponsiveness 3 days after ozone. Our findings indicate ozone causes persistent alterations in airway eosinophils and reinforce the importance of characterizing eosinophils' effects within distinct airway compartments.
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Affiliation(s)
- Sarah A Wicher
- Department of Physiology and Pharmacology, Oregon Health & Sciences University, Portland, Oregon
| | - Katy L Lawson
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Allison D Fryer
- Department of Physiology and Pharmacology, Oregon Health & Sciences University, Portland, Oregon
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
| | - Matthew G Drake
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Oregon Health & Science University, Portland, Oregon
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11
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Mazzone SB, Undem BJ. Vagal Afferent Innervation of the Airways in Health and Disease. Physiol Rev 2017; 96:975-1024. [PMID: 27279650 DOI: 10.1152/physrev.00039.2015] [Citation(s) in RCA: 326] [Impact Index Per Article: 46.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vagal sensory neurons constitute the major afferent supply to the airways and lungs. Subsets of afferents are defined by their embryological origin, molecular profile, neurochemistry, functionality, and anatomical organization, and collectively these nerves are essential for the regulation of respiratory physiology and pulmonary defense through local responses and centrally mediated neural pathways. Mechanical and chemical activation of airway afferents depends on a myriad of ionic and receptor-mediated signaling, much of which has yet to be fully explored. Alterations in the sensitivity and neurochemical phenotype of vagal afferent nerves and/or the neural pathways that they innervate occur in a wide variety of pulmonary diseases, and as such, understanding the mechanisms of vagal sensory function and dysfunction may reveal novel therapeutic targets. In this comprehensive review we discuss historical and state-of-the-art concepts in airway sensory neurobiology and explore mechanisms underlying how vagal sensory pathways become dysfunctional in pathological conditions.
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Affiliation(s)
- Stuart B Mazzone
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Australia; and Department of Medicine, Johns Hopkins University Medical School, Asthma & Allergy Center, Baltimore, Maryland
| | - Bradley J Undem
- School of Biomedical Sciences, The University of Queensland, St Lucia, Brisbane, Australia; and Department of Medicine, Johns Hopkins University Medical School, Asthma & Allergy Center, Baltimore, Maryland
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12
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House JS, Nichols CE, Li H, Brandenberger C, Virgincar RS, DeGraff LM, Driehuys B, Zeldin DC, London SJ. Vagal innervation is required for pulmonary function phenotype in Htr4-/- mice. Am J Physiol Lung Cell Mol Physiol 2017; 312:L520-L530. [PMID: 28130264 PMCID: PMC5407097 DOI: 10.1152/ajplung.00495.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/19/2017] [Accepted: 01/25/2017] [Indexed: 11/22/2022] Open
Abstract
Human genome-wide association studies have identified over 50 loci associated with pulmonary function and related phenotypes, yet follow-up studies to determine causal genes or variants are rare. Single nucleotide polymorphisms in serotonin receptor 4 (HTR4) are associated with human pulmonary function in genome-wide association studies and follow-up animal work has demonstrated that Htr4 is causally associated with pulmonary function in mice, although the precise mechanisms were not identified. We sought to elucidate the role of neural innervation and pulmonary architecture in the lung phenotype of Htr4-/- animals. We report here that the Htr4-/- phenotype in mouse is dependent on vagal innervation to the lung. Both ex vivo tracheal ring reactivity and in vivo flexiVent pulmonary functional analyses demonstrate that vagotomy abrogates the Htr4-/- airway hyperresponsiveness phenotype. Hyperpolarized 3He gas magnetic resonance imaging and stereological assessment of wild-type and Htr4-/- mice reveal no observable differences in lung volume, inflation characteristics, or pulmonary microarchitecture. Finally, control of breathing experiments reveal substantive differences in baseline breathing characteristics between mice with/without functional HTR4 in breathing frequency, relaxation time, flow rate, minute volume, time of inspiration and expiration and breathing pauses. These results suggest that HTR4's role in pulmonary function likely relates to neural innervation and control of breathing.
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Affiliation(s)
- John S House
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Cody E Nichols
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Huiling Li
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | | | - Rohan S Virgincar
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Biomedical Engineering, Duke University, Durham, North Carolina
| | - Laura M DeGraff
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Bastiaan Driehuys
- Center for In Vivo Microscopy, Duke University Medical Center, Durham, North Carolina.,Biomedical Engineering, Duke University, Durham, North Carolina.,Radiology, Duke University Medical Center, Durham, North Carolina; and
| | - Darryl C Zeldin
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Stephanie J London
- Immunity, Inflammation, and Disease Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina; .,Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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13
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Audrit KJ, Delventhal L, Aydin Ö, Nassenstein C. The nervous system of airways and its remodeling in inflammatory lung diseases. Cell Tissue Res 2017; 367:571-590. [PMID: 28091773 DOI: 10.1007/s00441-016-2559-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/13/2016] [Indexed: 12/20/2022]
Abstract
Inflammatory lung diseases are associated with bronchospasm, cough, dyspnea and airway hyperreactivity. The majority of these symptoms cannot be primarily explained by immune cell infiltration. Evidence has been provided that vagal efferent and afferent neurons play a pivotal role in this regard. Their functions can be altered by inflammatory mediators that induce long-lasting changes in vagal nerve activity and gene expression in both peripheral and central neurons, providing new targets for treatment of pulmonary inflammatory diseases.
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Affiliation(s)
- Katrin Julia Audrit
- Institute of Anatomy and Cell Biology, Aulweg 123, 35385, Giessen, Germany.,German Center for Lung Research (DZL), Giessen, Germany
| | - Lucas Delventhal
- Institute of Anatomy and Cell Biology, Aulweg 123, 35385, Giessen, Germany.,German Center for Lung Research (DZL), Giessen, Germany
| | - Öznur Aydin
- Institute of Anatomy and Cell Biology, Aulweg 123, 35385, Giessen, Germany.,German Center for Lung Research (DZL), Giessen, Germany
| | - Christina Nassenstein
- Institute of Anatomy and Cell Biology, Aulweg 123, 35385, Giessen, Germany. .,German Center for Lung Research (DZL), Giessen, Germany.
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14
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Pleasants RA, Wang T, Gao J, Tang H, Donohue JF. Inhaled Umeclidinium in COPD Patients: A Review and Meta-Analysis. Drugs 2016; 76:343-61. [PMID: 26755180 DOI: 10.1007/s40265-015-0532-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A number of new agents for the management of chronic obstructive pulmonary disease (COPD) are at different stages of development, including several inhaled long-acting antimuscarinics (LAMA). Long-acting bronchodilators are considered to be central to the management of COPD due to the evidence supporting their efficacy and safety. Umeclidinium, a LAMA, has recently been approved for the maintenance treatment of moderate to very severe COPD in a number of countries. This comprehensive review and pooled meta-analysis provides detailed information about the efficacy and safety of this agent. The pharmacokinetics and pharmacodynamics of umeclidinium observed in phase I and II studies support its once-daily administration. Umeclidinium is rapidly cleared from blood, and renal or hepatic impairment do not lead to significant changes in drug disposition. A pooled analysis of phase III and comparative studies of umeclidinium in patients with moderate to very severe COPD showed significant improvement in lung function measures, including trough forced expiratory volume in 1 s (FEV1), as well as in acute exacerbations of COPD, dyspnea, and quality of life. Adverse effects, including known anticholinergic effects, were uncommon with umeclidinium. Limited data suggest the efficacy of umeclidinium is similar to that of tiotropium. Umeclidinium is administered as a dry powder inhaler, provides adequate lung delivery in patients with moderate to very severe airflow obstruction, and appears to be easily used by patients. Umeclidinium provides a safe and effective option as an inhaled LAMA for the management of COPD.
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Affiliation(s)
- Roy A Pleasants
- Duke University Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Asthma, Allergy, and Airways Center, 1821 Hillandale Rd Suite 25A, Durham, NC, 27705, USA.
| | - Tiansheng Wang
- Department of Pharmacy Administration and Clinical Pharmacy, Peking University Health Science Center, Beijing, China
| | - Jinming Gao
- Department of Respiratory Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Huilin Tang
- Department of Pharmacy, Peking University Third Hospital, Beijing, China
| | - James F Donohue
- Division of Pulmonary Diseases and Critical Care Medicine, UNC Chapel Hill, Chapel Hill, NC, USA
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15
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Smooth muscle in human bronchi is disposed to resist airway distension. Respir Physiol Neurobiol 2016; 229:51-8. [PMID: 27095271 DOI: 10.1016/j.resp.2016.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 04/11/2016] [Accepted: 04/14/2016] [Indexed: 11/21/2022]
Abstract
Studying airway smooth muscle (ASM) in conditions that emulate the in vivo environment within which the bronchi normally operate may provide important clues regarding its elusive physiological function. The present study examines the effect of lengthening and shortening of ASM on tension development in human bronchial segments. ASM from each bronchial segment was set at a length approximating in situ length (Linsitu). Bronchial tension was then measured during a slow cyclical strain (0.004Hz, from 0.7Linsitu to 1.3Linsitu) in the relaxed state and at graded levels of activation by methacholine. In all cases, tension was greater at longer ASM lengths, and greater during lengthening than shortening. The threshold of methacholine concentration that was required for ASM to account for bronchial tension across the entire range of ASM lengths tested was on average smaller by 2.8 logs during lengthening than during shortening. The length-dependency of ASM tension, together with this lower threshold of methacholine concentration during lengthening versus shortening, suggest that ASM has a greater ability to resist airway dilation during lung inflation than to narrow the airways during lung deflation. More than serving to narrow the airway, as has long been thought, these data suggest that the main function of ASM contraction is to limit airway wall distension during lung inflation.
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16
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McGovern AE, Mazzone SB. Guinea pig models of asthma. CURRENT PROTOCOLS IN PHARMACOLOGY 2014; 67:5.26.1-5.26.38. [PMID: 25446291 DOI: 10.1002/0471141755.ph0526s67] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Described in this unit are methods for establishing guinea pig models of asthma. Sufficient detail is provided to enable investigators to study bronchoconstriction, cough, airway hyperresponsiveness, inflammation, and remodeling.
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Affiliation(s)
- Alice E McGovern
- School of Biomedical Sciences, University of Queensland, St Lucia, Australia
| | - Stuart B Mazzone
- School of Biomedical Sciences, University of Queensland, St Lucia, Australia
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17
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Price D, Fromer L, Kaplan A, van der Molen T, Román-Rodríguez M. Is there a rationale and role for long-acting anticholinergic bronchodilators in asthma? NPJ Prim Care Respir Med 2014; 24:14023. [PMID: 25030457 PMCID: PMC4373380 DOI: 10.1038/npjpcrm.2014.23] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 02/14/2014] [Accepted: 03/28/2014] [Indexed: 01/11/2023] Open
Abstract
Despite current guidelines and the range of available treatments, over a half of patients with asthma continue to suffer from poor symptomatic control and remain at risk of future worsening. Although a number of non-pharmacological measures are crucial for good clinical management of asthma, new therapeutic controller medications will have a role in the future management of the disease. Several long-acting anticholinergic bronchodilators are under investigation or are available for the treatment of respiratory diseases, including tiotropium bromide, aclidinium bromide, glycopyrronium bromide, glycopyrrolate and umeclidinium bromide, although none is yet licensed for the treatment of asthma. A recent Phase III investigation demonstrated that the once-daily long-acting anticholinergic bronchodilator tiotropium bromide improves lung function and reduces the risk of exacerbation in patients with symptomatic asthma, despite the use of inhaled corticosteroids (ICS) and long-acting β2-agonists (LABAs). This has prompted the question of what the rationale is for long-acting anticholinergic bronchodilators in asthma. Bronchial smooth muscle contraction is the primary cause of reversible airway narrowing in asthma, and the baseline level of contraction is predominantly set by the level of ‘cholinergic tone’. Patients with asthma have increased bronchial smooth muscle tone and mucus hypersecretion, possibly as a result of elevated cholinergic activity, which anticholinergic compounds are known to reduce. Further, anticholinergic compounds may also have anti-inflammatory properties. Thus, evidence suggests that long-acting anticholinergic bronchodilators might offer benefits for the maintenance of asthma control, such as in patients failing to gain control on ICS and a LABA, or those with frequent exacerbations.
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Affiliation(s)
- David Price
- 1] Centre of Academic Primary Care, University of Aberdeen, Aberdeen, UK [2] Research in Real Life Ltd, Cambridge, UK
| | - Leonard Fromer
- Department of Family Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Alan Kaplan
- Family Physician Airways Group of Canada, Richmond Hill, ON, Canada
| | - Thys van der Molen
- Department of General Practice, University of Groningen, University Medical Center, Groningen, The Netherlands
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18
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McGovern AE, Mazzone SB. Neural regulation of inflammation in the airways and lungs. Auton Neurosci 2014; 182:95-101. [DOI: 10.1016/j.autneu.2013.12.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Accepted: 12/12/2013] [Indexed: 10/25/2022]
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19
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Abstract
Autonomic neural control of the intrathoracic airways aids in optimizing air flow and gas exchange. In addition, and perhaps more importantly, the autonomic nervous system contributes to host defense of the respiratory tract. These functions are accomplished by tightly regulating airway caliber, blood flow, and secretions. Although both the sympathetic and parasympathetic branches of the autonomic nervous system innervate the airways, it is the later that dominates, especially with respect to control of airway smooth muscle and secretions. Parasympathetic tone in the airways is regulated by reflex activity often initiated by activation of airway stretch receptors and polymodal nociceptors. This review discusses the preganglionic, ganglionic, and postganglionic mechanisms of airway autonomic innervation. Additionally, it provides a brief overview of how dysregulation of the airway autonomic nervous system may contribute to respiratory diseases.
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20
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Säfholm J, Dahlén SE, Delin I, Maxey K, Stark K, Cardell LO, Adner M. PGE2 maintains the tone of the guinea pig trachea through a balance between activation of contractile EP1 receptors and relaxant EP2 receptors. Br J Pharmacol 2013; 168:794-806. [PMID: 22934927 DOI: 10.1111/j.1476-5381.2012.02189.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 07/23/2012] [Accepted: 08/20/2012] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE The guinea pig trachea (GPT) is commonly used in airway pharmacology. The aim of this study was to define the expression and function of EP receptors for PGE(2) in GPT as there has been ambiguity concerning their role. EXPERIMENTAL APPROACH Expression of mRNA for EP receptors and key enzymes in the PGE(2) pathway were assessed by real-time PCR using species-specific primers. Functional studies of GPT were performed in tissue organ baths. KEY RESULTS Expression of mRNA for the four EP receptors was found in airway smooth muscle. PGE(2) displayed a bell-shaped concentration-response curve, where the initial contraction was inhibited by the EP(1) receptor antagonist ONO-8130 and the subsequent relaxation by the EP(2) receptor antagonist PF-04418948. Neither EP(3) (ONO-AE5-599) nor EP(4) (ONO-AE3-208) selective receptor antagonists affected the response to PGE(2). Expression of COX-2 was greater than COX-1 in GPT, and the spontaneous tone was most effectively abolished by selective COX-2 inhibitors. Furthermore, ONO-8130 and a specific PGE(2) antibody eliminated the spontaneous tone, whereas the EP(2) antagonist PF-04418948 increased it. Antagonists of other prostanoid receptors had no effect on basal tension. The relaxant EP(2) response to PGE(2) was maintained after long-term culture, whereas the contractile EP(1) response showed homologous desensitization to PGE(2), which was prevented by COX-inhibitors. CONCLUSIONS AND IMPLICATIONS Endogenous PGE(2), synthesized predominantly by COX-2, maintains the spontaneous tone of GPT by a balance between contractile EP(1) receptors and relaxant EP(2) receptors. The model may be used to study interactions between EP receptors.
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Affiliation(s)
- J Säfholm
- Unit for Experimental Asthma and Allergy Research, Centre for Allergy Research, The Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
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21
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Ultra-LAMA, ultra-LABA, ultra-inhaled steroids? The future has landed. Arch Bronconeumol 2013; 49:131-4. [PMID: 23415574 DOI: 10.1016/j.arbres.2012.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 11/12/2012] [Accepted: 11/28/2012] [Indexed: 11/24/2022]
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22
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Abstract
The airways and lungs are innervated by both sympathetic and parasympathetic nerves. Cholinergic parasympathetic innervation is well conserved in the airways while the distribution of noncholinergic parasympathetic and adrenergic sympathetic nerves varies considerably amongst species. Autonomic nerve function is regulated primarily through reflexes initiated upon bronchopulmonary vagal afferent nerves. Central regulation of autonomic tone is poorly described but some key elements have been defined.
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Affiliation(s)
- Stuart B Mazzone
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
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23
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Neuronal modulation of airway and vascular tone and their influence on nonspecific airways responsiveness in asthma. J Allergy (Cairo) 2012; 2012:108149. [PMID: 23150736 PMCID: PMC3485909 DOI: 10.1155/2012/108149] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 09/28/2012] [Indexed: 01/08/2023] Open
Abstract
The autonomic nervous system provides both cholinergic and noncholinergic neural inputs to end organs within the airways, which includes the airway and vascular smooth muscle. Heightened responsiveness of the airways to bronchoconstrictive agents is a hallmark feature of reactive airways diseases. The mechanisms underpinning airways hyperreactivity still largely remain unresolved. In this paper we summarize the substantial body of evidence that implicates dysfunction of the autonomic nerves that innervate smooth muscle in the airways and associated vasculature as a prominent cause of airways hyperresponsiveness in asthma.
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24
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Design and synthesis of new 8-anilide theophylline derivatives as bronchodilators and antibacterial agents. Arch Pharm Res 2012; 35:1355-68. [PMID: 22941478 DOI: 10.1007/s12272-012-0805-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 11/21/2011] [Accepted: 11/24/2011] [Indexed: 10/27/2022]
Abstract
Theophylline derivatives have long been recognized as potent bronchodilators for the relief of acute asthma. Recently, it was found that bacterial infection has a role in asthma pathogenesis. The present work involves the design and synthesis of 8-substituted theophylline derivatives as bronchodilators and antibacterial agents. The chemical structures of these compounds were elucidated by IR, (1)H-NMR, mass spectrometry, and elemental analyses. The bronchodilator activity was evaluated using acetylcholine-induced bronchospasm in guinea pigs, and most of the compounds showed significant anti-bronchoconstrictive activity in comparison with standard aminophylline. In addition, the antibacterial activity of all the target compounds was investigated in vitro against Gram-positive and Gram-negative bacteria using ampicillin as a reference drug. Results showed that some of the tested compounds possessed significant antibacterial activity. A pharmacophore model was computed to obtain useful insight into the essential structural features of bronchodilator activity. A structure activity relationship was also discussed.
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25
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Cazzola M, Page CP, Calzetta L, Matera MG. Pharmacology and therapeutics of bronchodilators. Pharmacol Rev 2012; 64:450-504. [PMID: 22611179 DOI: 10.1124/pr.111.004580] [Citation(s) in RCA: 307] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Bronchodilators are central in the treatment of of airways disorders. They are the mainstay of the current management of chronic obstructive pulmonary disease (COPD) and are critical in the symptomatic management of asthma, although controversies around the use of these drugs remain. Bronchodilators work through their direct relaxation effect on airway smooth muscle cells. at present, three major classes of bronchodilators, β(2)-adrenoceptor (AR) agonists, muscarinic receptor antagonists, and xanthines are available and can be used individually or in combination. The use of the inhaled route is currently preferred to minimize systemic effects. Fast- and short-acting agents are best used for rescue of symptoms, whereas long-acting agents are best used for maintenance therapy. It has proven difficult to discover novel classes of bronchodilator drugs, although potential new targets are emerging. Consequently, the logical approach has been to improve the existing bronchodilators, although several novel broncholytic classes are under development. An important step in simplifying asthma and COPD management and improving adherence with prescribed therapy is to reduce the dose frequency to the minimum necessary to maintain disease control. Therefore, the incorporation of once-daily dose administration is an important strategy to improve adherence. Several once-daily β(2)-AR agonists or ultra-long-acting β(2)-AR-agonists (LABAs), such as indacaterol, olodaterol, and vilanterol, are already in the market or under development for the treatment of COPD and asthma, but current recommendations suggest the use of LABAs only in combination with an inhaled corticosteroid. In addition, some new potentially long-acting antimuscarinic agents, such as glycopyrronium bromide (NVA-237), aclidinium bromide, and umeclidinium bromide (GSK573719), are under development, as well as combinations of several classes of long-acting bronchodilator drugs, in an attempt to simplify treatment regimens as much as possible. This review will describe the pharmacology and therapeutics of old, new, and emerging classes of bronchodilator.
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Affiliation(s)
- Mario Cazzola
- Università di Roma Tor Vergata, Dipartimento di Medicina Interna, Via Montpellier 1, 00133 Roma, Italy.
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26
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Mazzone SB, Canning BJ. Guinea pig models of asthma. ACTA ACUST UNITED AC 2012; Chapter 5:Unit 5.26. [PMID: 22294077 DOI: 10.1002/0471141755.ph0526s16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This unit describes methods for establishing guinea pig models of asthma. Detailed descriptions are provided so that investigators can establish preparations in which bronchoconstriction, airways hyperresponsiveness, cough and airways inflammation can be studied.
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Affiliation(s)
- Stuart B Mazzone
- The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
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27
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Matera MG, Calzetta L, Segreti A, Cazzola M. Emerging drugs for chronic obstructive pulmonary disease. Expert Opin Emerg Drugs 2012; 17:61-82. [DOI: 10.1517/14728214.2012.660917] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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28
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Chen Y, Wang L, Zhou X, Ge D, Yuan W, Wang J. Agonist of 5-HT1A/7 receptors but not that of 5-HT2 receptors disinhibits tracheobronchial-projecting airway vagal preganglionic neurons of rats. Neuroscience 2012; 207:78-87. [PMID: 22342968 DOI: 10.1016/j.neuroscience.2012.01.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/16/2012] [Accepted: 01/31/2012] [Indexed: 01/08/2023]
Abstract
The vagus nerves supply the major cholinergic tone to airway smooth muscles physiologically and play critical roles in the genesis of airway hyperreactivity under some pathological conditions. Postganglionic airway cholinergic tone relies largely on the ongoing activity of medullary airway vagal preganglionic neurons (AVPNs), of which the tracheobronchial-projecting ones are primarily located in the external formation of the nucleus ambiguus (eNA). AVPNs are regulated by 5-HT, and 5-HT(1A/7) and 5-HT(2) receptors have been indicated to be involved. But the mechanisms at synaptic level are unknown. In the present study, tracheobronchial-projecting AVPNs (T-AVPNs) were retrogradely labeled from the trachea wall; fluorescently labeled T-AVPNs in the eNA were recorded with whole-cell voltage patch clamp; and the effects of 5-HT(1A/7) receptor agonist (±)-8-Hydroxy-2-(dipropylamino) tetralin hydrobromide (8-OH-DPAT) (1 μmol L(-1)) and 5-HT(2) receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) (10 μmol L(-1)) on the synaptic inputs were examined. 8-OH-DPAT significantly inhibited the GABAergic and glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of T-AVPNs in both the frequency and amplitude but had no effect on the GABAergic and glycinergic miniature inhibitory postsynaptic currents (mIPSCs). The 8-OH-DPAT inhibition of the GABAergic and glycinergic sIPSCs was prevented by 5-HT(1A/7) receptor antagonist N-[2-[4-(2-Methoxyphenyl)-1-piperazinyl] ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate salt (WAY-100635) (1 μmol L(-1)). 8-OH-DPAT had no effect on the glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) and caused no alterations in the baseline current and input resistance of T-AVPNs. DOI had no effect on any types of the synaptic inputs of T-AVPNs. These results suggest that 5-HT(1A/7) receptor agonist causes "disinhibition" of T-AVPNs, which might, in part, account for the reflex increase of airway resistance.
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Affiliation(s)
- Y Chen
- The State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University Shanghai Medical College, Shanghai, PR China
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29
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Abstract
In healthy lungs, muscarinic receptors control smooth muscle tone, mucus secretion, vasodilation, and inflammation. In chronic obstructive pulmonary disease (COPD) and asthma, cholinergic mechanisms contribute to increased bronchoconstriction and mucus secretion that limit airflow. This chapter reviews neuronal and nonneuronal sources of acetylcholine in the lung and the expression and role of M₁, M₂, and M₃ muscarinic receptor subtypes in lung physiology. It also discusses the evidence for and against the role of parasympathetic nerves in asthma, and the current use and therapeutic potential of muscarinic receptor antagonists in COPD and asthma.
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Affiliation(s)
- Kalmia S. Buels
- Oregon Health and Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR 97239, USA
| | - Allison D. Fryer
- Oregon Health and Science University, 3181 SW Sam Jackson Park Road, UHN67, Portland, OR 97239, USA
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30
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Zhou J, Alvarez-Elizondo MB, Botvinick E, George SC. Local small airway epithelial injury induces global smooth muscle contraction and airway constriction. J Appl Physiol (1985) 2011; 112:627-37. [PMID: 22114176 DOI: 10.1152/japplphysiol.00739.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Small airway epithelial cells form a continuous sheet lining the conducting airways, which serves many functions including a physical barrier to protect the underlying tissue. In asthma, injury to epithelial cells can occur during bronchoconstriction, which may exacerbate airway hyperreactivity. To investigate the role of epithelial cell rupture in airway constriction, laser ablation was used to precisely rupture individual airway epithelial cells of small airways (<300-μm diameter) in rat lung slices (∼250-μm thick). Laser ablation of single epithelial cells using a femtosecond laser reproducibly induced airway contraction to ∼70% of the original cross-sectional area within several seconds, and the contraction lasted for up to 40 s. The airway constriction could be mimicked by mechanical rupture of a single epithelial cell using a sharp glass micropipette but not with a blunt glass pipette. These results suggest that soluble mediators released from the wounded epithelial cell induce global airway contraction. To confirm this hypothesis, the lysate of primary human small airway epithelial cells stimulated a similar airway contraction. Laser ablation of single epithelial cells triggered a single instantaneous Ca(2+) wave in the epithelium, and multiple Ca(2+) waves in smooth muscle cells, which were delayed by several seconds. Removal of extracellular Ca(2+) or decreasing intracellular Ca(2+) both blocked laser-induced airway contraction. We conclude that local epithelial cell rupture induces rapid and global airway constriction through release of soluble mediators and subsequent Ca(2+)-dependent smooth muscle shortening.
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Affiliation(s)
- Jian Zhou
- Department of Biomedical Engineering, Universityof California, Irvine, CA 92697-2715, USA
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31
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Design and synthesis of some new theophylline derivatives with bronchodilator and antibacterial activities. Arch Pharm Res 2011; 34:3-21. [PMID: 21468910 DOI: 10.1007/s12272-011-0101-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Revised: 06/28/2010] [Accepted: 06/30/2010] [Indexed: 10/18/2022]
Abstract
Methylxanthines especially theophylline have been recognized as potent bronchodilators for the relief of acute asthma for over 65 years. Recently, it was found that bacterial infection plays a role in asthma pathogenesis. Accordingly, the present work involves the synthesis of 6-(4-(un)substituted phenyl)thiazolo[2,3-f]theophyllines 2a-g and different series of 8-(1,2,4-triazol-3-ylmethylthio)theophyllines 6-9. The chemical structures of the target compounds were proved by IR, (1)H NMR, (13)C NMR, EI-MS and HRMS spectroscopic techniques along with elemental analyses. The bronchodilator activity of fifteen compounds was determined in vivo by acetylcholine induced bronchospasm in anaesthetized guinea pigs. Results revealed that all compounds showed moderate to good activity; in addition, five compounds exhibited a bronchodilator activity nearly similar to that of aminophylline as a standard. The antibacterial activity of all the target compounds was investigated in vitro against both Gram-positive and Gram-negative bacterial strains. Results revealed that some compounds showed more potent antibacterial activity than ampicillin as a standard. Acute toxicity study for four target compounds revealed that none of these derivatives showed significant toxicity up to 300 mg/kg. It was found that compound 8c combined both promising bronchodilator and antibacterial activities. This compound could be subjected for further investigations as a new possible candidate in the treatment of bronchial asthma.
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32
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Canning BJ, Mori N. Encoding of the cough reflex in anesthetized guinea pigs. Am J Physiol Regul Integr Comp Physiol 2010; 300:R369-77. [PMID: 20926760 DOI: 10.1152/ajpregu.00044.2010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have previously described the physiological and morphological properties of the cough receptors and their sites of termination in the airways and centrally in the nucleus tractus solitarius (nTS). In the present study, we have addressed the hypothesis that the primary central synapses of the cough receptors subserve an essential role in the encoding of cough. We found that cough requires sustained, high-frequency (≥8-Hz) afferent nerve activation. We also found evidence for processes that both facilitate (summation, sensitization) and inhibit the initiation of cough. Sensitization of cough occurs with repetitive subthreshold activation of the cough receptors or by coincident activation of C-fibers and/or nTS neurokinin receptor activation. Desensitization of cough evoked by repetitive and/or continuous afferent nerve activation has a rapid onset (<60 s) and does not differentiate between tussive stimuli, suggesting a central nervous system-dependent process. The cough reflex can also be actively inhibited upon activation of other airway afferent nerve subtypes, including slowly adapting receptors and pulmonary C-fibers. The sensitization and desensitization of cough are likely attributable to the prominent, primary, and unique role of N-methyl-d-aspartate receptor-dependent signaling at the central synapses of the cough receptors. These attributes may have direct relevance to the presentation of cough in disease and for the effectiveness of antitussive therapies.
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Affiliation(s)
- Brendan J Canning
- Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
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33
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Goyal M, Jaseja H, Verma N. Increased parasympathetic tone as the underlying cause of asthma: a hypothesis. Med Hypotheses 2010; 74:661-4. [PMID: 20044211 DOI: 10.1016/j.mehy.2009.11.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 11/16/2009] [Indexed: 02/08/2023]
Abstract
Asthma is a chronic inflammatory disease of airways that is characterized by increased responsiveness of the tracheo-bronchial tree to multiple number of stimuli. Immunological theory does not explain all features in asthma, for example hyper-reactivity of the airways. Neurogenic theory also fails to explain the pathogenesis of asthma comprehensively. Higher parasympathetic tone has been reported in asthmatics but has never been suggested as a major underlying cause of asthma. This article attempts to explain the occurrence of hyper-responsiveness, inflammatory/allergic reactions and broncho-constriction in asthma on a common basis of inherent higher parasympathetic tone in asthmatics. The higher background parasympathetic firing leads to increased nitric oxide (NO) production owing to its co-localization with acetylcholine (ACh) in inhibitory non-adrenergic and non-cholinergic (i-NANC) nerves. NO is a neurotransmitter of i-NANC system and it mediates bronchodilation. Increased NO release has been found to be responsible for hyper-responsiveness and increased inflammation in the airways. The authors suggest that an inherently higher background parasympathetic tone in concert with inflammation or a specific genetic background could modify the effects of NO on lung homeostasis in humans leading to increased susceptibility to an asthmatic state.
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Affiliation(s)
- Manish Goyal
- Department of Physiology, All India Institute of Medical Sciences, New Delhi 110 029, India.
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Weigand LA, Myers AC. Synaptic and membrane properties of parasympathetic ganglionic neurons innervating mouse trachea and bronchi. Am J Physiol Lung Cell Mol Physiol 2010; 298:L593-9. [PMID: 20118300 DOI: 10.1152/ajplung.00386.2009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pathophysiology of airway diseases, such as asthma, is increasingly studied using transgenic mice and other mouse models of airway inflammation where allergen-induced changes in airway smooth muscle tone and mucous secretion is due, in part, to activation of preganglionic airway parasympathetic nerves. Ganglionic parasympathetic neurons located in the airways in several species, including humans, have anatomical and electrophysiological properties that limit transmission of preganglionic synaptic input. In this study, intracellular recordings were made from neurons in parasympathetic ganglia located on the trachea and bronchi of adult mice to determine electrophysiological properties associated with regulation of transmission of preganglionic input. Ganglionic neurons were characterized as having either tonic or phasic action potential accommodation patterns. Tonic neurons responded with repetitive action potentials sustained throughout a depolarizing current step, whereas phasic neurons generated one or a burst of action potential(s) and accommodated. A small subset displayed both patterns. Phasic neurons could be further differentiated as usually having either short- or long-duration afterhyperpolarizing potential following single and multiple action potentials. In most cells, stimulation of preganglionic nerves elicited one population of nicotinic fast excitatory postsynaptic potentials that were graded in amplitude, usually suprathreshold for action potential generation, and did not decrease in amplitude during higher frequency stimulation. Dye injection into the neurons revealed that dendrites were either absent or very short. These results provide evidence that in contrast to the characteristics of airway parasympathetic neurons reported in other species, including human, the electrophysiological and synaptic properties, and anatomical characteristics of mouse lower airway ganglionic neurons, are less associated with integration of presynaptic input.
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Affiliation(s)
- Letitia A Weigand
- The Johns Hopkins University School of Medicine, Division of Allergy and Clinical Immunology, The Johns Hopkins Asthma and Allergy Center, Baltimore, Maryland 21224, USA
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Abstract
The lung, like many other organs, is innervated by a variety of sensory nerves and by nerves of the parasympathetic and sympathetic nervous systems that regulate the function of cells within the respiratory tract. Activation of sensory nerves by both mechanical and chemical stimuli elicits a number of defensive reflexes, including cough, altered breathing pattern, and altered autonomic drive, which are important for normal lung homeostasis. However, diseases that afflict the lung are associated with altered reflexes, resulting in a variety of symptoms, including increased cough, dyspnea, airways obstruction, and bronchial hyperresponsiveness. This review summarizes the current knowledge concerning the physiological role of different sensory nerve subtypes that innervate the lung, the factors which lead to their activation, and pharmacological approaches that have been used to interrogate the function of these nerves. This information may potentially facilitate the identification of novel drug targets for the treatment of respiratory disorders such as cough, asthma, and chronic obstructive pulmonary disease.
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ANSELL TK, NOBLE PB, MITCHELL HW, WEST AR, FERNANDES LB, MCFAWN PK. Effects of simulated tidal and deep breathing on immature airway contraction to acetylcholine and nerve stimulation. Respirology 2009; 14:991-8. [DOI: 10.1111/j.1440-1843.2009.01596.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Undem BJ, Nassenstein C. Airway nerves and dyspnea associated with inflammatory airway disease. Respir Physiol Neurobiol 2008; 167:36-44. [PMID: 19135556 DOI: 10.1016/j.resp.2008.11.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 11/27/2008] [Accepted: 11/28/2008] [Indexed: 01/28/2023]
Abstract
The neurobiology of dyspnea is varied and complex, but there is little doubt that vagal nerves within the airways are capable of causing or modulating some dyspneic sensations, especially those associated with inflammatory airway diseases. A major contributor to the dyspnea associated with inflammatory airway disease is explained by airway narrowing and increases in the resistance to airflow. The autonomic (parasympathetic) airway nerves directly contribute to this by regulating bronchial smooth muscle tone and mucus secretion. In addition, a component of the information reaching the brainstem via airway mechanosensing and nociceptive afferent nerves likely contributes to the overall sensations of breathing. The airway narrowing can lead to activation of low threshold mechanosensitive stretch receptors, and vagal and spinal C-fibers as well as some rapidly adapting stretch receptor in the airways that are directly activated by various aspects of the inflammatory response. Inflammatory mediators can induce long lasting changes in afferent nerve activity by modulating the expression of key genes. The net effect of the increase in afferent traffic to the brainstem modulates synaptic efficacy at the second-order neurons via various mechanisms collectively referred to as central sensitization. Many studies have shown that stimuli that activate bronchopulmonary afferent nerves can lead to dyspnea in healthy subjects. A logical extension of the basic research on inflammation and sensory nerve function is that the role of vagal sensory nerve in causing or shaping dyspneic sensations will be exaggerated in those suffering from inflammatory airway disease.
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LaPrad AS, West AR, Noble PB, Lutchen KR, Mitchell HW. Maintenance of airway caliber in isolated airways by deep inspiration and tidal strains. J Appl Physiol (1985) 2008; 105:479-85. [PMID: 18556436 DOI: 10.1152/japplphysiol.01220.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Deep inspirations (DIs) are large periodic breathing maneuvers that regulate airway caliber and prevent airway obstruction in vivo. This study characterized the intrinsic response of the intact airway to DI, isolated from parenchymal attachments and other in vivo interactions. Porcine isolated bronchial segments were constricted with carbachol and subjected to transmural pressures of 5-10 cmH2O at 0.25 Hz (tidal breathing) interspersed with single DIs of amplitude 5-20 cmH2O, 5-30 cmH2O, or 5-40 cmH2O (6-s duration) or DI of amplitude 5-30 cmH2O (30-s duration). Tidal breathing was ceased after DI in a subset of airways and in control airways in which no DI was performed. Luminal cross-sectional area was measured using a fiber-optic endoscope. Bronchodilation by DI was amplitude dependent; 5-20 cmH2O DIs produced less dilation than 5-30 cmH2O and 5-40 cmH2O DIs (P=0.003 and 0.012, respectively). Effects of DI duration were not significant (P=0.182). Renarrowing after DI followed a monoexponential decay function to pre-DI airway caliber with time constants between 27.4+/-4.3 and 36.3+/-6.9 s. However, when tidal breathing was ceased after DI, further bronchoconstriction occurred within 30s. This response was identical in both the presence and absence of DI (P=0.919). We conclude that the normal bronchodilatory response to DI occurs as a result of the direct mechanical effects of DI on activated ASM in the airway wall. Further bronchoconstriction occurs by altering the airway wall stress following DI, demonstrating the importance of continual transient strains in maintaining airway caliber.
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Affiliation(s)
- Adam S LaPrad
- Department of Biomedical Engineering, Boston University, 44 Cummington St., Boston, MA 02215, USA.
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Reynolds SM, Docherty R, Robbins J, Spina D, Page CP. Adenosine induces a cholinergic tracheal reflex contraction in guinea pigs in vivo via an adenosine A1 receptor-dependent mechanism. J Appl Physiol (1985) 2008; 105:187-96. [PMID: 18420718 DOI: 10.1152/japplphysiol.01048.2007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Adenosine induces dyspnea, cough, and airways obstruction in asthma, a phenomenon that also occurs in various sensitized animal models in which a neuronal involvement has been implicated. Although adenosine has been suggested to activate cholinergic nerves, the precise mechanism has not been established. In the present study, the adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA) induced a cholinergic reflex, causing tracheal smooth muscle contraction that was significantly inhibited by the adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 100 microg/kg) (P < 0.05) in anesthetized animals. Furthermore, the adenosine A(2) agonist 2-p-(2-carboxyethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS-21680) induced a small reflex, whereas the A(3) selective agonist N(6)-(3-iodobenzyl)-5'-N-methylcarbamoyladenosine (IB-MECA) was without effect. The tracheal reflex induced by CPA was also inhibited by recurrent nerve ligation or muscarinic receptor blockade (P < 0.001), indicating that a cholinergic neuronal mechanism of action accounted for this response. The cholinergic reflex in response to aerosolized CPA was significantly greater in passively sensitized compared with naive guinea pigs (P < 0.01). Chronic capsaicin treatment, which inhibited sensory nerve function, failed to inhibit CPA-induced reflex tracheal contractions in passively sensitized guinea pigs, although the local anesthetic lidocaine inhibited CPA-induced tracheal contractions. The effects of CPA on the reflex response was not dependent on the release of histamine from tissue mast cells or endogenous prostaglandins as shown by the lack of effect of the histamine H(1) receptor antagonist pyrilamine (1 mg/kg) or the cyclooxygenase inhibitor meclofenamic acid (3 mg/kg), respectively. In conclusion, activation of pulmonary adenosine A(1) receptors can stimulate cholinergic reflexes, and these reflexes are increased in allergic guinea pigs.
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Affiliation(s)
- Sandra M Reynolds
- Pharmaceutical Science Research Division, The Sackler Institute of Pulmonary Pharmacology, School of Biomedical and Health Science, King's College London, London SE1 1UL, UK
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Abstract
The guinea pig has been the most commonly used small animal species in preclinical studies related to asthma and COPD. The primary advantages of the guinea pig are the similar potencies and efficacies of agonists and antagonists in human and guinea pig airways and the many similarities in physiological processes, especially airway autonomic control and the response to allergen. The primary disadvantages to using guinea pigs are the lack of transgenic methods, limited numbers of guinea pig strains for comparative studies and a prominent axon reflex that is unlikely to be present in human airways. These attributes and various models developed in guinea pigs are discussed.
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Affiliation(s)
- Brendan J Canning
- Johns Hopkins Asthma and Allergy Center, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
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Bates JHT, Cojocaru A, Lundblad LKA. Bronchodilatory effect of deep inspiration on the dynamics of bronchoconstriction in mice. J Appl Physiol (1985) 2007; 103:1696-705. [PMID: 17885022 DOI: 10.1152/japplphysiol.00698.2007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We recently developed a computational model of an airway embedded in elastic parenchyma (Bates JH, Lauzon AM. J Appl Physiol 102: 1912-1920, 2007) that accurately mimics the time dependence of airway resistance on tidal volume and positive end-expiratory pressure (PEEP) following methacholine injection in normal animals. In the present study, we compared the model predictions of bronchodilation induced by a deep inflation (DI) of the lung following administration of the bronchial agonist methacholine to corresponding experimental measurements made in mice. We found that a DI in mice caused an immediate reduction in airway resistance when it was administered soon after intravenous injection of methacholine, while the airway smooth muscle was in the process of contracting. However, the magnitude of the reduction in resistance was greater and its subsequent rate of increase less than that predicted by the model. We found that this effect was most pronounced when the DI was given within approximately 3 s following methacholine injection, again in contrast to the predictions of the model. The reduction of airway resistance was virtually independent of the rate of lung inflation during the DI, however, which agrees with model predictions. We conclude that while the model accounts for a substantial fraction of the post-DI reduction in airway resistance seen experimentally, there remain important differences between prediction and experiment that suggest that the effects of a DI are not simply due to eccentric contraction of the airway smooth muscle.
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Affiliation(s)
- Jason H T Bates
- Vermont Lung Center, University of Vermont College of Medicine, Burlington, Vermont.
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Kitsiopoulou E, Hatziefthimiou AA, Gourgoulianis KI, Molyvdas PA. Resting tension affects eNOS activity in a calcium-dependent way in airways. Mediators Inflamm 2007; 2007:24174. [PMID: 17515950 PMCID: PMC1868075 DOI: 10.1155/2007/24174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 02/05/2007] [Indexed: 11/18/2022] Open
Abstract
The alteration of resting tension (RT) from 0.5 g to 2.5 g increased significantly airway smooth muscle contractions induced by acetylcholine (ACh) in rabbit trachea. The decrease in extracellular calcium concentration [Ca2+]o from 2 mM to 0.2 mM reduced ACh-induced contractions only at 2.5 g RT with no effect at 0.5 g RT. The nonselective inhibitor of nitric oxide synthase (NOS), NG-nitro-L-arginine methyl ester (L-NAME) increased ACh-induced contractions at
2.5 g RT. The inhibitor of inducible NOS, S-methylsothiourea or neuronal
NOS, 7-nitroindazole had no effect. At 2.5 g RT, the reduction of [Ca2+]o from 2 mM to 0.2 mM abolished the effect of L-NAME on ACh-induced contractions. The NO precursor L-arginine or the tyrosine kinase inhibitors erbstatin A and genistein had no effect on ACh-induced contractions obtained at 2.5 g RT. Our results suggest that in airways, RT affects ACh-induced contractions by modulating the activity of epithelial NOS in a calcium-dependent, tyrosine-phosphorylation-independent way.
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Affiliation(s)
- Eudoxia Kitsiopoulou
- Department of Physiology, Medical School, University of Thessaly, Papakiriazi 22, 41222 Larissa, Greece
| | - Apostolia A. Hatziefthimiou
- Department of Physiology, Medical School, University of Thessaly, Papakiriazi 22, 41222 Larissa, Greece
- *Apostolia A. Hatziefthimiou:
| | | | - Paschalis-Adam Molyvdas
- Department of Physiology, Medical School, University of Thessaly, Papakiriazi 22, 41222 Larissa, Greece
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Noble PB, McFawn PK, Mitchell HW. Responsiveness of the isolated airway during simulated deep inspirations: effect of airway smooth muscle stiffness and strain. J Appl Physiol (1985) 2007; 103:787-95. [PMID: 17510300 DOI: 10.1152/japplphysiol.00314.2007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In vivo, breathing movements, including tidal and deep inspirations (DIs), exert a number of beneficial effects on respiratory system responsiveness in healthy humans that are diminished or lost in asthma, possibly as a result of reduced distension (strain) of airway smooth muscle (ASM). We used bronchial segments from pigs to assess airway responsiveness under static conditions and during simulated tidal volume oscillations with and without DI and to determine the roles of airway stiffness and ASM strain on responsiveness. To simulate airway dilations during breathing, we cycled the luminal volume of liquid-filled segments. Volume oscillations (15 cycles/min) were set so that, in relaxed airways, they produced a transmural pressure increase of approximately 5-10 cmH(2)O for tidal maneuvers and approximately 5-30 cmH(2)O for DIs. ACh dose-response curves (10(-7)-3 x 10(-3) M) were constructed under static and dynamic conditions, and maximal response and sensitivity were determined. Airway stiffness was measured from tidal trough-to-peak pressure and volume cycles. ASM strain produced by DI was estimated from luminal volume, airway length, and inner wall area. DIs produced substantial ( approximately 40-50%) dilation, reflected by a decrease in maximal response (P < 0.001) and sensitivity (P < 0.05). However, the magnitude of bronchodilation decreased significantly in proportion to airway stiffening caused by contractile activation and an associated reduction in ASM strain. Tidal oscillations, in comparison, had little effect on responsiveness. We conclude that DI regulates airway responsiveness at the airway level, but this is limited by airway stiffness due to reduced ASM strain.
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Affiliation(s)
- Peter B Noble
- Physiology, School of Biomedical, Biomolecular, and Chemical Sciences, Univ. of Western Australia, 35 Stirling Hwy., Crawley, Perth, Western Australia, 6009, Australia.
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Lewis MJ, Short AL, Lewis KE. Autonomic nervous system control of the cardiovascular and respiratory systems in asthma. Respir Med 2006; 100:1688-705. [PMID: 16524708 DOI: 10.1016/j.rmed.2006.01.019] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2005] [Revised: 01/19/2006] [Accepted: 01/25/2006] [Indexed: 12/01/2022]
Abstract
Patients with asthma have exaggerated bronchoconstriction of their airways in response to certain indirect (e.g. cold air, allergens, dust, exercise) or direct (e.g. inhaled methacholine) stimuli. This 'hyper-reactivity' usually co-exists with airway inflammation, although the pathophysiological mechanisms underlying these changes are not fully understood. It is likely that this hyper-reactivity is associated with abnormal autonomic nervous system (ANS) control. In particular, the parasympathetic (vagal) component of the ANS appears to be implicated in the pathogenesis of asthma. In addition, several studies have suggested the existence of differential alteration in ANS function following exercise in asthmatics compared with non-asthmatic individuals. Several early studies suggested that the altered autonomic control of airway calibre in asthma might be reflected by a parallel change in heart rate. Cardiac vagal reactivity does indeed appear to be increased in asthma, as demonstrated by the cardiac response to various autonomic functions tests. However, other studies have reported a lack of association between bronchial and cardiac vagal tone, and this is in accord with the concept of system-independent ANS control. This review provides a discussion of cardiovascular-autonomic changes associated with either the pathophysiology of asthma per se or with asthma pharmacotherapy treatment. Previous investigations are summarised suggesting an apparent association between altered autonomic-cardiovascular control and bronchial asthma. The full extent of autonomic dysfunction, and its clinical implications, has yet to be fully determined and should be the subject of future investigation.
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Affiliation(s)
- M J Lewis
- Department of Sports Science, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK.
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Abstract
Autonomic nerves in most mammalian species mediate both contractions and relaxations of airway smooth muscle. Cholinergic-parasympathetic nerves mediate contractions, whereas adrenergic-sympathetic and/or noncholinergic parasympathetic nerves mediate relaxations. Sympathetic-adrenergic innervation of human airway smooth muscle is sparse or nonexistent based on histological analyses and plays little or no role in regulating airway caliber. Rather, in humans and in many other species, postganglionic noncholinergic parasympathetic nerves provide the only relaxant innervation of airway smooth muscle. These noncholinergic nerves are anatomically and physiologically distinct from the postganglionic cholinergic parasympathetic nerves and differentially regulated by reflexes. Although bronchopulmonary vagal afferent nerves provide the primary afferent input regulating airway autonomic nerve activity, extrapulmonary afferent nerves, both vagal and nonvagal, can also reflexively regulate autonomic tone in airway smooth muscle. Reflexes result in either an enhanced activity in one or more of the autonomic efferent pathways, or a withdrawal of baseline cholinergic tone. These parallel excitatory and inhibitory afferent and efferent pathways add complexity to autonomic control of airway caliber. Dysfunction or dysregulation of these afferent and efferent nerves likely contributes to the pathogenesis of obstructive airways diseases and may account for the pulmonary symptoms associated with extrapulmonary disorders, including gastroesophageal reflux disease, cardiovascular disease, and rhinosinusitis.
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46
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Undem BJ, Kollarik M. The role of vagal afferent nerves in chronic obstructive pulmonary disease. Ann Am Thorac Soc 2006; 2:355-60; discussion 371-2. [PMID: 16267362 PMCID: PMC2713327 DOI: 10.1513/pats.200504-033sr] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Circumstantial evidence supports the hypothesis that the vagal nervous system is dysregulated in chronic obstructive pulmonary disease. This dysregulation can lead to an increased sensitivity of the cough reflex such that the coughing becomes, at times, "nonproductive" or inappropriate. Vagal dysregulation can also lead to an increase in the activity of the parasympathetic reflex control of the airways, which contributes to greater mucus secretion and bronchial smooth muscle contraction. Indirect evidence indicates that lung disease is accompanied by substantive changes to the entire reflex pathways, including enhanced activity of the primary afferent nerves, increases in synaptic efficacy at secondary nerves in the central nervous system, and changes in the autonomic nerve pathways. Drugs aimed at normalizing neuronal activity may, therefore, be beneficial in chronic obstructive pulmonary disease.
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Affiliation(s)
- Bradley J Undem
- Johns Hopkins Asthma Center, Johns Hopkins School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
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47
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Canning B, Mazzone S. Reflexes Initiated by Activation of the Vagal Afferent Nerves Innervating the Airways and Lungs. ADVANCES IN VAGAL AFFERENT NEUROBIOLOGY 2005. [DOI: 10.1201/9780203492314.ch15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Scichilone N, Togias A. The role of lung inflation in airway hyperresponsiveness and in asthma. Curr Allergy Asthma Rep 2004; 4:166-74. [PMID: 14769267 DOI: 10.1007/s11882-004-0063-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Airway hyperresponsiveness (AHR) is a fundamental phenomenon in asthma that can explain many aspects of the clinical manifestations of the disease. Several theories on the mechanisms of AHR have been proposed, but the true nature of this problem is yet to be defined. During the past decade, the role of lung inflation in airway physiology and its relationship to AHR have attracted major attention. Deep inspirations are known to exert strong beneficial effects on the airways of healthy humans. These effects appear to be of dual nature: bronchoprotective and bronchodilatory. The bronchoprotective effect of deep inspiration is lost in asthma, even in mild disease. It is also lost in individuals with rhinitis and AHR, but no asthma. Therefore, the loss of bronchoprotection is related to AHR. The bronchodilatory effect of deep inspiration is somewhat reduced in mild asthma and is only lost in severe disease, in the presence of significant airway obstruction. Current research is focused on the elucidation of the physiologic mechanisms behind lung inflation-induced bronchoprotection and bronchodilation and on the causes of their loss. This information could open new horizons in asthma therapy and prevention.
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Affiliation(s)
- Nicola Scichilone
- Divisions of Allergy and Clinical Immunology and Respiratory and Critical Care Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA
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Noble PB, McFawn PK, Mitchell HW. Intraluminal pressure oscillation enhances subsequent airway contraction in isolated bronchial segments. J Appl Physiol (1985) 2004; 96:1161-5. [PMID: 14634031 DOI: 10.1152/japplphysiol.01082.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A period of deep inspiration in humans has been shown to attenuate subsequent bronchoconstriction, a phenomenon termed bronchoprotection. The bronchoprotective effect of deep inspiration may be caused though a depression in the force production of airway smooth muscle (ASM). We determined the response of whole airway segments and isolated ASM to a period of cyclic stretches. Isovolumetric contraction to electrical field stimulation (EFS) was assessed in porcine bronchial segments before and after intraluminal pressure oscillation from 5 to 25 cmH2O for 10 min at 0.5 Hz. Morphometry showed that this pressure oscillation stretched ASM length by 21%. After pressure oscillation, the response to EFS was not reduced but instead was modestly enhanced ( P < 0.01). Airway responses to EFS returned to preoscillation levels 10 min after the end of oscillation. The increase in EFS response after pressure oscillation was not altered by the addition of indomethacin. In a separate experiment, we assessed isometric force in isolated ASM strips before and after length oscillation. The amplitude, frequency, and duration of length oscillation were similar to those induced in bronchial segments. In contrast to bronchial segments, length oscillation of ASM produced a significant depression in isometric force induced by EFS ( P < 0.01). These results suggest that the response of ASM to length oscillation is modified by the airway wall. They also suggest that the phenomenon of bronchoprotection reported in some in vivo studies may not be an intrinsic property of the airway.
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Affiliation(s)
- P B Noble
- Physiology, School of Biomedical and Chemical Sciences, University of Western Australia, Crawley, Perth, Western Australia 6009, Australia
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50
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Braun A, Lommatzsch M, Neuhaus-Steinmetz U, Quarcoo D, Glaab T, McGregor GP, Fischer A, Renz H. Brain-derived neurotrophic factor (BDNF) contributes to neuronal dysfunction in a model of allergic airway inflammation. Br J Pharmacol 2004; 141:431-40. [PMID: 14718253 PMCID: PMC1574219 DOI: 10.1038/sj.bjp.0705638] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is a candidate molecule for mediating functional neuronal changes in allergic bronchial asthma. Recently, enhanced production of BDNF during allergic airway inflammation caused by infiltrating T-cells and macrophages as well as by resident airway epithelial cells has been described. It was the aim of this study to investigate the effect of enhanced BDNF levels on lung function and airway inflammation in a mouse model of allergic inflammation. Ovalbumin-sensitised BALB/c mice were challenged in two consecutive allergen challenges. Prior to the challenge, the mice were treated with either anti-BDNF antibodies or isotype-matched control antibodies. Airway responsiveness to methacholine, capsaicin and electric field stimulation, as well as airway inflammation and chronic airway obstruction 1 week after the last allergen challenge were assessed. Anti-BDNF blocked enhanced reactivity in response to capsaicin, but not airway smooth muscle hyper-reactivity in vivo. Furthermore, persistent airway obstruction, as observed 1 week after the last allergen challenge, was to a large extent prevented by anti-BDNF treatment. In vitro, BDNF and anti-BDNF treatment had a profound effect on local neuronal hyper-reactivity, as shown by electric field stimulation experiments. In contrast, neither BDNF nor anti-BDNF treatment affected airway inflammation. Our data indicate that development of allergen-induced neuronal hyper-reactivity in mice is partially mediated by BDNF. British Journal of Pharmacology (2004) 141, 431-440. doi:10.1038/sj.bjp.0705638
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Affiliation(s)
- Armin Braun
- Department of Immunology and Allergology, Fraunhofer Institute of Toxicology and Experimental Medicine, Nikolai-Fuchs-Strasse 1, Hannover D-30625, Germany.
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