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Chan PYS, Lee LY, Davenport PW. Neural mechanisms of respiratory interoception. Auton Neurosci 2024; 253:103181. [PMID: 38696917 DOI: 10.1016/j.autneu.2024.103181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/03/2024] [Accepted: 04/22/2024] [Indexed: 05/04/2024]
Abstract
Respiratory interoception is one of the internal bodily systems that is comprised of different types of somatic and visceral sensations elicited by different patterns of afferent input and respiratory motor drive mediating multiple respiratory modalities. Respiratory interoception is a complex system, having multiple afferents grouped into afferent clusters and projecting into both discriminative and affective centers that are directly related to the behavioral assessment of breathing. The multi-afferent system provides a spectrum of input that result in the ability to interpret the different types of respiratory interceptive sensations. This can result in a response, commonly reported as breathlessness or dyspnea. Dyspnea can be differentiated into specific modalities. These respiratory sensory modalities lead to a general sensation of an Urge-to-Breathe, driven by a need to compensate for the modulation of ventilation that has occurred due to factors that have affected breathing. The multiafferent system for respiratory interoception can also lead to interpretation of the sensory signals resulting in respiratory related sensory experiences, including the Urge-to-Cough and Urge-to-Swallow. These behaviors are modalities that can be driven through the differentiation and integration of multiple afferent input into the respiratory neural comparator. Respiratory sensations require neural somatic and visceral interoceptive elements that include gated attention and detection leading to respiratory modality discrimination with subsequent cognitive decision and behavioral compensation. Studies of brain areas mediating cortical and subcortical respiratory sensory pathways are summarized and used to develop a model of an integrated respiratory neural network mediating respiratory interoception.
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Affiliation(s)
- Pei-Ying Sarah Chan
- Department of Occupational Therapy, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Psychiatry, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
| | - Lu-Yuan Lee
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Paul W Davenport
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
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Zhao HZ, Guo ZW, Wang ZL, Wang C, Luo XY, Han NN, Li CR, Zheng HD, Hui ZY, Long Y, Zhao YL, Li QJ, Wang SY, Zhang GW. A Comparative Study of the Effects of Electronic Cigarette and Traditional Cigarette on the Pulmonary Functions of C57BL/6 Male Mice. Nicotine Tob Res 2024; 26:474-483. [PMID: 37535700 DOI: 10.1093/ntr/ntad139] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 07/11/2023] [Accepted: 08/02/2023] [Indexed: 08/05/2023]
Abstract
INTRODUCTION Electronic cigarettes (E-cigs) are in a controversial state. Although E-cig aerosol generally contains fewer harmful substances than smoke from burned traditional cigarettes, aerosol along with other compounds of the E-cigs may also affect lung functions and promote the development of lung-related diseases. We investigated the effects of E-cig on the pulmonary functions of male C57BL/6 mice and reveal the potential underlying mechanisms. METHODS A total of 60 male C57BL/6 mice were randomly divided into four groups. They were exposed to fresh-air, traditional cigarette smoke, E-cig vapor with 12 mg/mL of nicotine, and E-cig with no nicotine for 8 weeks. Lung functions were evaluated by using quantitative analysis of the whole body plethysmograph, FlexiVent system, lung tissue histological and morphometric analysis, and RT-PCR analysis of mRNA expression of inflammation-related genes. In addition, the effects of nicotine and acrolein on the survival rate and DNA damage were investigated using cultured human alveolar basal epithelial cells. RESULTS Exposure to E-cig vapor led to significant changes in lung functions and structures including the rupture of the alveolar cavity and enlarged alveolar space. The pathological changes were also accompanied by increased expression of interleukin-6 and tumor necrosis factor-α. CONCLUSIONS The findings of the present study indicate that the safety of E-cig should be further evaluated. IMPLICATIONS Some people currently believe that using nicotine-free E-cigs is a safe way to smoke. However, our research shows that E-cigs can cause lung damage regardless of whether they contain nicotine.
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Affiliation(s)
- Han-Zhi Zhao
- School of Public Health, Xi'an Medical University, Xi'an, China
- People's Hospital of Shaanxi province, Xi'an, China
- Office of Graduate Student Affairs, Xi'an Medical University, Xi'an, China
| | - Zi-Wei Guo
- Xi'an Gem Flower Chang Qing Hospital, Xi'an, China
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
| | - Zhang-Li Wang
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
- Institute of Health Sciences, China Medical University, Shenyang, China
| | - Chen Wang
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
- Institute of Health Sciences, China Medical University, Shenyang, China
| | - Xian-Yu Luo
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Ning-Ning Han
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
| | - Chen-Rui Li
- Academy of life sciences, northwestern polytechnical university, Xi'an, China
| | - Hua-Dong Zheng
- Department of Gerontology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Zi-Yi Hui
- The second clinical medical school of Xi'an Medical University, Xi'an, China
| | - Yang Long
- The second clinical medical school of Xi'an Medical University, Xi'an, China
| | - Yan-Lei Zhao
- The second clinical medical school of Xi'an Medical University, Xi'an, China
| | - Qiu-Jin Li
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
| | - Sheng-Yu Wang
- School of Public Health, Xi'an Medical University, Xi'an, China
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
- The First Affiliated Hospital of Xi'an Medical University, Xi'an, China
| | - Guang-Wei Zhang
- School of Public Health, Xi'an Medical University, Xi'an, China
- Department of Basic Medicine, Xi'an Medical University, Xi'an, China
- Office of Graduate Student Affairs, Xi'an Medical University, Xi'an, China
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Park TJ, Reznick J. Extreme Physiology Extreme Tolerance to Hypoxia, Hypercapnia, and Pain in the Naked Mole-Rat. J Muscle Res Cell Motil 2023; 44:61-72. [PMID: 35854159 PMCID: PMC10329625 DOI: 10.1007/s10974-022-09623-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/04/2022] [Indexed: 10/17/2022]
Abstract
Challenging environmental conditions can drive the evolution of extreme physiological traits. The naked mole-rat has evolved to survive and thrive in a low oxygen, high carbon dioxide environment that would be deadly to humans and most other mammals. The naked mole-rat's lifestyle is unusual in that this species combines subterranean living and living in large, social groups of up to 300 + individuals. Many respiring animals in a closed environment can lead to depletion of oxygen (hypoxia) and accumulation of carbon dioxide (hypercapnia). Naked mole-rats display a variety of physiological traits that negate the adverse effects of living in this atmosphere. For hypoxia tolerance, naked mole-rats have a low resting metabolism, high affinity hemoglobin, intrinsic brain tolerance, the ability to use fructose for anaerobic glycolysis, and the ability to enter a low energy, suspended animation-like state. For hypercapnia tolerance, these animals have a mutation in a voltage gated sodium channel that effectively eliminates neuronal responses to tissue acidosis. In other mammals, acidosis from exposure to high concentrations of carbon dioxide induces pain and pulmonary edema. Understanding these mechanisms of extreme physiology is not only inherently interesting, but it may lead to biomedical breakthroughs in research on heart attacks, strokes, and pain pathologies.
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Affiliation(s)
- Thomas J Park
- Department of Biological Sciences and Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, IL, United States of America.
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany.
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Xu F, Zhao L, Zhuang J, Gao X. Peripheral Neuroplasticity of Respiratory Chemoreflexes, Induced by Prenatal Nicotinic Exposure: Implication for SIDS. Respir Physiol Neurobiol 2023; 313:104053. [PMID: 37019251 DOI: 10.1016/j.resp.2023.104053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/23/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023]
Abstract
Sudden Infant Death Syndrome (SIDS) occurs during sleep in seemingly healthy infants. Maternal cigarette smoking and hypoxemia during sleep are assumed to be the major causal factors. Depressed hypoxic ventilatory response (dHVR) is observed in infants with high risk of SIDS, and apneas (lethal ventilatory arrest) appear during the fatal episode of SIDS. Disturbance of the respiratory center has been proposed to be involved, but the pathogenesis of SIDS is still not fully understood. Peripherally, the carotid body is critical to generate HVR, and bronchopulmonary and superior laryngeal C-fibers (PCFs and SLCFs) are important for triggering central apneas; however, their roles in the pathogenesis of SIDS have not been explored until recently. There are three lines of recently accumulated evidence to show the disorders of peripheral sensory afferent-mediated respiratory chemoreflexes in rat pups with prenatal nicotinic exposure (a SIDS model) in which acute severe hypoxia leads to dHVR followed by lethal apneas. (1) The carotid body-mediated HVR is suppressed with a reduction of the number and sensitivity of glomus cells. (2) PCF-mediated apneic response is largely prolonged via increased PCF density, pulmonary IL-1β and serotonin (5-hydroxytryptamine, 5-HT) release, along with the enhanced expression of TRPV1, NK1R, IL1RI and 5-HT3R in pulmonary C-neurons to strengthen these neural responses to capsaicin, a selective stimulant to C-fibers. (3) SLCF-mediated apnea and capsaicin-induced currents in superior laryngeal C-neurons are augmented by upregulation of TRPV1 expression in these neurons. These results, along with hypoxic sensitization/stimulation of PCFs, gain insight into the mechanisms of prenatal nicotinic exposure-induced peripheral neuroplasticity responsible for dHVR and long-lasting apnea during hypoxia in rat pups. Therefore, in addition to the disturbance in the respiratory center, the disorders of peripheral sensory afferent-mediated chemoreflexes may also be involved in respiratory failure and death denoted in SIDS victims.
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Abstract
Coughing is a dynamic physiological process resulting from input of vagal sensory neurons innervating the airways and perceived airway irritation. Although cough serves to protect and clear the airways, it can also be exploited by respiratory pathogens to facilitate disease transmission. Microbial components or infection-induced inflammatory mediators can directly interact with sensory nerve receptors to induce a cough response. Analysis of cough-generated aerosols and transmission studies have further demonstrated how infectious disease is spread through coughing. This review summarizes the neurophysiology of cough, cough induction by respiratory pathogens and inflammation, and cough-mediated disease transmission.
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Affiliation(s)
- Kubra F Naqvi
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, University of Melbourne, Victoria, Australia
| | - Michael U Shiloh
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA;
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Jareonsettasin P, Zeicu C, Diehl B, Harper RM, Astin R. Inappropriate Ventilatory Homeostatic Responses in Hospitalized COVID-19 Patients. Front Neurol 2022; 13:909915. [PMID: 35785338 PMCID: PMC9240262 DOI: 10.3389/fneur.2022.909915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/19/2022] [Indexed: 11/15/2022] Open
Abstract
Background The clinical presentation of COVID-19 suggests altered breathing control - tachypnoea, relative lack of dyspnoea, and often a discrepancy between severity of clinical and radiological findings. Few studies characterize and analyse the contribution of breathing drivers and their ventilatory and perceptual responses. Aim To establish the prevalence of inappropriate ventilatory and perceptual response in COVID-19, by characterizing the relationships between respiratory rate (RR), dyspnoea and arterial blood gas (ABG) in a cohort of COVID-19 patients at presentation to hospital, and their post-Covid respiratory sequelae at follow-up. Methods We conducted a retrospective cohort study including consecutive adult patients admitted to hospital with confirmed COVID-19 between 1st March 2020 and 30th April 2020. In those with concurrent ABG, RR and documented dyspnoea status on presentation, we documented patient characteristics, disease severity, and outcomes at hospital and 6-week post-discharge. Results Of 492 admissions, 194 patients met the inclusion criteria. Tachypnoea was present in 75% pronounced (RR>30) in 36%, and persisted during sleep. RR correlated with heart rate (HR) (r = 0.2674), temperature (r = 0.2824), CRP (r = 0.2561), Alveolar-arterial (A-a) gradient (r = 0.4189), and lower PaO2/FiO2 (PF) ratio (r = −0.3636). RR was not correlated with any neurological symptoms. Dyspnoea was correlated with RR (r = 0.2932), A-a gradient (r = 0.1723), and lower PF ratio (r = −0.1914), but not correlated with PaO2 (r = −0.1095), PaCO2 (r = −0.0598) or any recorded neurological symptom except for altered consciousness. Impaired ventilatory homeostatic control of pH/PaCO2 [tachypnoea (RR>20), hypocapnia (PaCO2 <4.6 kPa), and alkalosis (pH>7.45)] was observed in 29%. This group, of which 37% reported no dyspnoea, had more severe respiratory disease (A-a gradient 38.9 vs. 12.4 mmHg; PF ratio 120 vs. 238), and higher prevalence of anosmia (21 vs. 15%), dysgeusia (25 vs. 12%), headache (33 vs. 23%) and nausea (33 vs. 14%) with similar rates of new anxiety/depression (26 vs. 23%), but lower incidence of past neurological or psychiatric diagnoses (5 vs. 21%) compared to appropriate responders. Only 5% had hypoxia sufficiently severe to drive breathing (i.e. PaO2 <6.6 kPa). At 6 weeks post-discharge, 24% (8/34) showed a new breathing pattern disorder with no other neurological findings, nor previous respiratory, neurological, or psychiatric disorder diagnoses. Conclusions Impaired homeostatic control of ventilation i.e., tachypnoea, despite hypocapnia to the point of alkalosis appears prevalent in patients admitted to hospital with COVID-19, a finding typically accompanying more severe disease. Tachypnoea prevalence was between 12 and 29%. Data suggest that excessive tachypnoea is driven by both peripheral and central mechanisms, but not hypoxia. Over a third of patients with impaired homeostatic ventilatory control did not experience dyspnoea despite tachypnoea. A subset of followed-up patients developed post-covid breathing pattern disorder.
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Affiliation(s)
- Prem Jareonsettasin
- Department of Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, United Kingdom
- Division of Medical Specialties, University College London Hospitals NHS Foundation Trust, London, United Kingdom
- *Correspondence: Prem Jareonsettasin
| | - Claudia Zeicu
- Department of Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, United Kingdom
- Division of Medical Specialties, University College London Hospitals NHS Foundation Trust, London, United Kingdom
| | - Beate Diehl
- Department of Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, United Kingdom
- Department of Clinical Neurophysiology, University College London Hospitals NHS Foundation Trust National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Ronald M. Harper
- Department of Neurobiology and the Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Rónan Astin
- Division of Medical Specialties, University College London Hospitals NHS Foundation Trust, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
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Veerakumar A, Yung AR, Liu Y, Krasnow MA. Molecularly defined circuits for cardiovascular and cardiopulmonary control. Nature 2022; 606:739-746. [PMID: 35650438 PMCID: PMC9297035 DOI: 10.1038/s41586-022-04760-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 04/13/2022] [Indexed: 01/29/2023]
Abstract
The sympathetic and parasympathetic nervous systems powerfully regulate internal organs1, but the molecular and functional diversity of their constituent neurons and circuits remains largely unknown. Here we use retrograde neuronal tracing, single-cell RNA sequencing, optogenetics, and physiological experiments to dissect the cardiac parasympathetic control circuit in mice. We show that cardiac-innervating neurons in the brainstem nucleus ambiguus (Amb) are comprised of two molecularly, anatomically, and functionally distinct subtypes. One we call ACV (ambiguus cardiovascular) neurons (~35 neurons per Amb), define the classical cardiac parasympathetic circuit. They selectively innervate a subset of cardiac parasympathetic ganglion neurons and mediate the baroreceptor reflex, slowing heart rate and atrioventricular node conduction in response to increased blood pressure. The other, ACP (ambiguus cardiopulmonary) neurons (~15 neurons per Amb) innervate cardiac ganglion neurons intermingled with and functionally indistinguishable from those innervated by ACV neurons, but surprisingly also innervate most or all lung parasympathetic ganglion neurons; clonal labeling shows individual ACP neurons innervate both organs. ACP neurons mediate the dive reflex, the simultaneous bradycardia and bronchoconstriction that follows water immersion. Thus, parasympathetic control of the heart is organized into two parallel circuits, one that selectively controls cardiac function (ACV circuit) and another that coordinates cardiac and pulmonary function (ACP circuit). This new understanding of cardiac control has implications for treating cardiac and pulmonary diseases and for elucidating the control and coordination circuits of other organs.
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Affiliation(s)
- Avin Veerakumar
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Medical Scientist Training Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Andrea R Yung
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Yin Liu
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark A Krasnow
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.
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A breathing mask attenuates acute airway responses to exercise in sub-zero environment in healthy subjects. Eur J Appl Physiol 2022; 122:1473-1484. [PMID: 35391634 PMCID: PMC9132816 DOI: 10.1007/s00421-022-04939-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/22/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE Cold air exposure is associated with increased respiratory morbidity and mortality. Repeated inhalation of cold and dry air is considered the cause of the high prevalence of asthma among winter endurance athletes. This study assessed whether a heat- and moisture-exchanging breathing device (HME) attenuates airway responses to high-intensity exercise in sub-zero temperatures among healthy subjects. METHODS Using a randomized cross-over design, 23 healthy trained participants performed a 30-min warm-up followed by a 4-min maximal, self-paced running time trial in - 15 °C, with and without HME. Lung function was assessed pre- and immediately post-trials. Club cell protein (CC-16), 8-isoprostane, and cytokine concentrations were measured in plasma and urine pre- and 60 min post trials. Symptoms were assessed prior to, during, and immediately after each trial in the chamber. RESULTS HME use attenuated the decrease in forced expiratory volume in 1 s (FEV1) post trials (∆FEV1: mean (SD) HME - 0.5 (1.9) % vs. no-HME - 2.7 (2.7) %, p = 0.002). HME also substantially attenuated the median relative increase in plasma-CC16 concentrations (with HME + 27% (interquartile range 9-38) vs no-HME + 121% (55-162), p < 0.001) and reduced airway and general symptom intensity, compared to the trial without HME. No significant changes between trials were detected in urine CC16, 8-isoprostane, or cytokine concentrations. CONCLUSION The HME attenuated acute airway responses induced by moderate-to-maximal-intensity exercise in - 15 °C in healthy subjects. Further studies are needed to examine whether this HMEs could constitute primary prevention against asthma in winter endurance athletes.
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Domnik NJ, Vincent SG, Fisher JT. Mechanosensitivity of Murine Lung Slowly Adapting Receptors: Minimal Impact of Chemosensory, Serotonergic, and Purinergic Signaling. Front Physiol 2022; 13:833665. [PMID: 35250636 PMCID: PMC8889033 DOI: 10.3389/fphys.2022.833665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Murine slowly adapting receptors (SARs) within airway smooth muscle provide volume-related feedback; however, their mechanosensitivity and morphology are incompletely characterized. We explored two aspects of SAR physiology: their inherent static mechanosensitivity and a potential link to pulmonary neuroepithelial bodies (NEBs). SAR mechanosensitivity displays a rate sensitivity linked to speed of inflation; however, to what extent static SAR mechanosensitivity is tuned for the very rapid breathing frequency (B f ) of small mammals (e.g., mouse) is unclear. NEB-associated, morphologically described smooth muscle-associated receptors (SMARs) may be a structural analog for functionally characterized SARs, suggesting functional linkages between SARs and NEBs. We addressed the hypotheses that: (1) rapid murine B f is associated with enhanced in vivo SAR static sensitivity; (2) if SARs and NEBs are functionally linked, stimuli reported to impact NEB function would alter SAR mechanosensitivity. We measured SAR action potential discharge frequency (AP f, action potentials/s) during quasi-static inflation [0-20 cmH2O trans-respiratory pressure (PTR)] in NEB-relevant conditions of hypoxia (FIO2 = 0.1), hypercarbia (FICO2 = 0.1), and pharmacologic intervention (serotonergic 5-HT3 receptor antagonist, Tropisetron, 4.5 mg/kg; P2 purinergic receptor antagonist, Suramin, 50 mg/kg). In all protocols, we obtained: (1) AP f vs. PTR; (2) PTR threshold; and (3) AP f onset at PTR threshold. The murine AP f vs. PTR response comprises high AP f (average maximum AP f: 236.1 ± 11.1 AP/s at 20 cmH2O), a low PTR threshold (mean 2.0 ± 0.1 cmH2O), and a plateau in AP f between 15 and 20 cmH2O. Murine SAR mechanosensitivity (AP f vs. PTR) is up to 60% greater than that reported for larger mammals. Even the maximum difference between intervention and control conditions was minimally impacted by NEB-related alterations: Tropisetron -7.6 ± 1.8% (p = 0.005); Suramin -10.6 ± 1.5% (p = 0.01); hypoxia +9.3 ± 1.9% (p < 0.001); and hypercarbia -6.2 ± 0.9% (p < 0.001). We conclude that the high sensitivity of murine SARs to inflation provides enhanced resolution of operating lung volume, which is aligned with the rapid B f of the mouse. We found minimal evidence supporting a functional link between SARs and NEBs and speculate that the <10% change in SAR mechanosensitivity during altered NEB-related stimuli is not consistent with a meaningful physiologic role.
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Affiliation(s)
- Nicolle J. Domnik
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Sandra G. Vincent
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
| | - John T. Fisher
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
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Low T, Lee CH, Chen YC, Lo CL, Huang YC, Lin JY, Wu SS, Lai CJ. Effect of Prolonged Mechanical Ventilation on Cough Function and TRPV1 Expression. Respir Physiol Neurobiol 2022; 299:103859. [PMID: 35121102 DOI: 10.1016/j.resp.2022.103859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/29/2022] [Accepted: 01/30/2022] [Indexed: 10/19/2022]
Abstract
Cough is a pivotal airway protective reflex, yet the effects of prolonged mechanical ventilation (PMV) on cough function are unknown. This study compared the cough function in subjects with PMV (≥ 21 days, n = 29) and those with short-term mechanical ventilation (SMV, ≤ 7 days, n = 27). Cough reflex sensitivity was measured by capsaicin provocation concentrations after extubation. The cough strength of respiratory muscles was assessed by involuntary cough peak expiratory flow (iCPEF). The mRNA expression of transient receptor potential vanilloid 1 (TRPV1), a cough sensor activated by capsaicin, in tracheal tissues was determined. We found that cough reflex sensitivity and iCPEF were significantly lower in the PMV group than in the SMV group. The tracheal expression of TRPV1 was similar in both groups, suggesting that changes in TRPV1 expression may not be a contributing factor. Our finding regarding the cough dysfunction after PMV highlights the need to implement effective airway clearance management and rehabilitation in this population.
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Affiliation(s)
- Tissot Low
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan; Division of Chest Medicine, Department of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Chien-Hui Lee
- Department of Neurosurgery, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Yen-Cheng Chen
- Division of General Surgery, Department of Surgery, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chun-Lan Lo
- Division of Chest Medicine, Department of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Ya-Chen Huang
- Division of Chest Medicine, Department of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Jyun-Yi Lin
- Division of Chest Medicine, Department of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Siao-Syuan Wu
- Division of Chest Medicine, Department of Internal Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
| | - Ching Jung Lai
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan; Department of Physiology, Tzu Chi University, Hualien, Taiwan.
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Amorim MA, Jentsch Matias de Oliveira JR, Souza Oliveira VH, Cabrini DA, Otuki MF, André E. Role of nitric oxide, bradykinin B 2 receptor, and TRPV1 in the airway alterations caused by simvastatin in rats. Eur J Pharmacol 2021; 912:174591. [PMID: 34710369 DOI: 10.1016/j.ejphar.2021.174591] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/01/2021] [Accepted: 10/20/2021] [Indexed: 10/20/2022]
Abstract
Dry cough has been reported in patients receiving statin therapy. However, the underlying mechanism or other possible alterations in the airways induced by statins remain unknown. Thus, the aim of this study was to evaluate whether simvastatin promotes alterations in airways, such as bronchoconstriction and plasma extravasation, as well as the mechanism involved in these events. Using methods to detect alterations in airway resistance and plasma extravasation, we demonstrated that simvastatin [20 mg/kg, intravenous (i.v.)] caused plasma extravasation in the trachea (79.8 + 14.8 μg/g/tissue) and bronchi (73.3 + 8.8 μg/g/tissue) of rats, compared to the vehicle (34.2 + 3.6 μg/g/tissue and 29.3 + 5.3 μg/g/tissue, respectively). NG-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg, intraperitoneal), a nitric oxide (NO) synthase inhibitor, Icatibant [HOE 140, 10 nmol/50 μl, intratracheal (i.t.)], a bradykinin B2 antagonist, and capsazepine (100 nmol/50 μl, i.t.), a TRPV1 antagonist, attenuated simvastatin-induced plasma extravasation. Simvastatin (5, 10 and 20 mg/kg) did not cause bronchoconstriction per se, but exacerbated the bronchoconstrictive response to bradykinin (30 nmol/kg, i.v.), a B2 agonist (0.7 + 0.1 ml/H2O), or capsaicin (30 nmol/kg, i.v.), a TRPV1 agonist (0.8 + 0.1 ml/H2O), compared to the vehicle (0.1 + 0.04 ml/H2O and 0.04 + 0.01 ml/H2O, respectively). The bronchoconstriction elicited by bradykinin (100 nmol/kg, i.v.) in simvastatin non-treated rats was inhibited by L-NAME. The exacerbation of bronchoconstriction induced by bradykinin or capsaicin in simvastatin-treated rats was inhibited by L-NAME, HOE 140 or capsazepine. These results suggest that treatment with simvastatin promotes the release of bradykinin, which, via B2 receptors, releases NO that can then activate the TRPV1 to promote plasma extravasation and bronchoconstriction.
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Affiliation(s)
| | | | | | | | | | - Eunice André
- Department of Pharmacology, Federal University of Paraná, Brazil.
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12
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Rouadi PW, Idriss SA, Bousquet J, Laidlaw TM, Azar CR, Sulaiman AL-Ahmad M, Yáñez A, AL-Nesf MAY, Nsouli TM, Bahna SL, Abou-Jaoude E, Zaitoun FH, Hadi UM, Hellings PW, Scadding GK, Smith PK, Morais-Almeida M, Gómez RM, González Díaz SN, Klimek L, Juvelekian GS, Riachy MA, Canonica GW, Peden D, Wong GW, Sublett J, Bernstein JA, Wang L, Tanno LK, Chikhladze M, Levin M, Chang YS, Martin BL, Caraballo L, Custovic A, Ortega-Martell JA, Jensen-Jarolim E, Ebisawa M, Fiocchi A, Ansotegui IJ. WAO-ARIA consensus on chronic cough - Part 1: Role of TRP channels in neurogenic inflammation of cough neuronal pathways. World Allergy Organ J 2021; 14:100617. [PMID: 34934475 PMCID: PMC8654622 DOI: 10.1016/j.waojou.2021.100617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Cough features a complex peripheral and central neuronal network. The function of the chemosensitive and stretch (afferent) cough receptors is well described but partly understood. It is speculated that chronic cough reflects a neurogenic inflammation of the cough reflex, which becomes hypersensitive. This is mediated by neuromediators, cytokines, inflammatory cells, and a differential expression of neuronal (chemo/stretch) receptors, such as transient receptor potential (TRP) and purinergic P2X ion channels; yet the overall interaction of these mediators in neurogenic inflammation of cough pathways remains unclear. OBJECTIVES The World Allergy Organization/Allergic Rhinitis and its Impact on Asthma (WAO/ARIA) Joint Committee on Chronic Cough reviewed the current literature on neuroanatomy and pathophysiology of chronic cough. The role of TRP ion channels in pathogenic mechanisms of the hypersensitive cough reflex was also examined. OUTCOMES Chemoreceptors are better studied in cough neuronal pathways compared to stretch receptors, likely due to their anatomical overabundance in the respiratory tract, but also their distinctive functional properties. Central pathways are important in suppressive mechanisms and behavioral/affective aspects of chronic cough. Current evidence strongly suggests neurogenic inflammation induces a hypersensitive cough reflex marked by increased expression of neuromediators, mast cells, and eosinophils, among others. TRP ion channels, mainly TRP V1/A1, are important in the pathogenesis of chronic cough due to their role in mediating chemosensitivity to various endogenous and exogenous triggers, as well as a crosstalk between neurogenic and inflammatory pathways in cough-associated airways diseases.
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Affiliation(s)
- Philip W. Rouadi
- Department of Otolaryngology - Head and Neck Surgery, Eye and Ear University Hospital, Beirut, Lebanon
| | - Samar A. Idriss
- Department of Otolaryngology - Head and Neck Surgery, Eye and Ear University Hospital, Beirut, Lebanon
- Department of Audiology and Otoneurological Evaluation, Edouard Herriot Hospital, Lyon, France
| | - Jean Bousquet
- Hospital Charité, Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Dermatology and Allergy, Comprehensive Allergy Center, Berlin Institute of Health, Berlin, Germany
- Macvia France, Montpellier France
- Université Montpellier, Montpellier, France
| | - Tanya M. Laidlaw
- Department of Medicine, Harvard Medical School, Division of Allergy and Clinical Immunology, Brigham and Women's Hospital Boston, MA, USA
| | - Cecilio R. Azar
- Department of Gastroenterology, American University of Beirut Medical Center (AUBMC), Beirut, Lebanon
- Department of Gastroenterology, Middle East Institute of Health (MEIH), Beirut, Lebanon
- Department of Gastroenterology, Clemenceau Medical Center (CMC), Beirut, Lebanon
| | | | - Anahí Yáñez
- INAER - Investigaciones en Alergia y Enfermedades Respiratorias, Buenos Aires, Argentina
| | - Maryam Ali Y. AL-Nesf
- Allergy and Immunology Section, Department of Medicine, Hamad Medical Corporation, P.O. Box 3050, Doha, Qatar
| | | | - Sami L. Bahna
- Allergy & Immunology Section, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | | | - Fares H. Zaitoun
- Department of Allergy Otolaryngology, LAU-RIZK Medical Center, Beirut, Lebanon
| | - Usamah M. Hadi
- Clinical Professor Department of Otolaryngology Head and Neck Surgery, American University of Beirut, Lebanon
| | - Peter W. Hellings
- KU Leuven Department of Microbiology, Immunology and Transplantation, Laboratory of Allergy and Clinical Immunology, Leuven, Belgium
- University Hospitals Leuven, Department of Otorhinolaryngology, Leuven, Belgium
- University Hospital Ghent, Department of Otorhinolaryngology, Laboratory of Upper Airways Research, Ghent, Belgium
- Academic Medical Center, University of Amsterdam, Department of Otorhinolaryngology, Amsterdam, the Netherlands
| | | | - Peter K. Smith
- Clinical Medicine Griffith University, Southport Qld, 4215, Australia
| | | | | | - Sandra N. González Díaz
- Universidad Autónoma de Nuevo León, Hospital Universitario and Facultad de Medicina, Monterrey, Nuevo León, Mexico
| | - Ludger Klimek
- Center for Rhinology and Allergology, Wiesbaden, Germany
| | - Georges S. Juvelekian
- Department of Pulmonary, Critical Care and Sleep Medicine at Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Moussa A. Riachy
- Department of Pulmonary and Critical Care, Hôtel-Dieu de France University Hospital, Beirut, Lebanon
| | - Giorgio Walter Canonica
- Humanitas University, Personalized Medicine Asthma & Allergy Clinic-Humanitas Research Hospital-IRCCS-Milano Italy
| | - David Peden
- UNC Center for Environmental Medicine, Asthma, and Lung Biology, Division of Allergy, Immunology and Rheumatology, Department of Pediatrics UNS School of Medicine, USA
| | - Gary W.K. Wong
- Department of Pediatrics, Chinese University of Hong Kong, Hong Kong, China
| | - James Sublett
- Department of Pediatrics, Section of Allergy and Immunology, University of Louisville School of Medicine, 9800 Shelbyville Rd, Louisville, KY, USA
| | - Jonathan A. Bernstein
- University of Cincinnati College of Medicine, Department of Internal Medicine, Division of Immunology/Allergy Section, Cincinnati
| | - Lianglu Wang
- Department of Allergy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Precision Medicine for Diagnosis and Treatment of Allergic Disease, State Key Laboratory of Complex Severe and Rare Diseases, National Clinical Research Center for Dermatologic and Immunologic Diseases (NCRC-DID), Beijing 100730, China
| | - Luciana Kase Tanno
- Université Montpellier, Montpellier, France
- Desbrest Institute of Epidemiology and Public Health, UMR UA-11, INSERM University of Montpellier, Montpellier, France
- WHO Collaborating Centre on Scientific Classification Support, Montpellier, France
| | - Manana Chikhladze
- Medical Faculty at Akaki Tsereteli State University, National Institute of Allergy, Asthma & Clinical Immunology, KuTaisi, Tskaltubo, Georgia
| | - Michael Levin
- Division of Paediatric Allergology, Department of Paediatrics, University of Cape Town, South Africa
| | - Yoon-Seok Chang
- Division of Allergy and Clinical Immunology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Bryan L. Martin
- Department of Otolaryngology, Division of Allergy & Immunology, The Ohio State University, Columbus, OH, USA
| | - Luis Caraballo
- Institute for Immunological Research, University of Cartagena. Cartagena de Indias, Colombia
| | - Adnan Custovic
- National Heart and Lund Institute, Imperial College London, UK
| | | | - Erika Jensen-Jarolim
- Institute of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University Vienna, Austria
- The Interuniversity Messerli Research Institute, Medical University Vienna and Univ, of Veterinary Medicine Vienna, Austria
| | - Motohiro Ebisawa
- Clinical Research Center for Allergy and Rheumatology,National Hospital Organization Sagamihara National Hospital, Sagamihara, Japan
| | - Alessandro Fiocchi
- Translational Pediatric Research Area, Allergic Diseases Research Unit, Bambino Gesù Children's Hospital IRCCS, Rome, Holy See
| | - Ignacio J. Ansotegui
- Department of Allergy and Immunology, Hospital Quironsalud Bizkaia, Bilbao, Spain
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Mendonça FT, Barreto Filho JH, Hungria MDBCS, Magalhães TC. Efficacy of a single dose of esmolol to prevent extubation-related complications during emergence from anesthesia: a randomized, double-blind, placebo-controlled trial. Braz J Anesthesiol 2021:S0104-0014(21)00340-7. [PMID: 34560115 PMCID: PMC10362437 DOI: 10.1016/j.bjane.2021.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 08/09/2021] [Accepted: 08/28/2021] [Indexed: 10/20/2022] Open
Abstract
BACKGROUND Few trials have examined the efficacy of esmolol to attenuate hemodynamic and respiratory responses during extubation. However, the most appropriate dose of esmolol and an optimal protocol for administering this beta-blocker are uncertain. METHODS Ninety patients ASA physical status I, II, and III (aged 18-60 years) scheduled to procedures with general anesthesia and tracheal extubation were selected. Patients were randomized into esmolol and placebo group to evaluate the efficacy and safety of a single bolus dose of esmolol (2 mg.kg-1) on cardiorespiratory responses during the peri-extubation period. The primary outcome was the rate of tachycardia during extubation. RESULTS The rate of tachycardia was significantly lower in esmolol-treated patients compared to placebo-treated patients (2.2% vs. 48.9%, relative risk (RR): 0.04, 95% confidence interval (95% CI) = 0.01 to 0.32, p = 0.002). The rate of hypertension was also significantly lower in the esmolol group (4.4% vs. 31.1%, RR: 0.14, 95% CI 0.03 to 0.6, p = 0.004). Esmolol-treated patients were associated with higher extubation quality compared to patients who received placebo (p < 0.001), with an approximately two-fold increase in the rate of patients without cough (91.1%) in the esmolol group compared to the placebo group (46.7%). The rate of bucking was approximately 5-fold lower in the esmolol group (8.9% vs. 44.5%, respectively, RR: 0.20 (95% CI, 0.1 to 0.5, p = 0.002, with an NNT of 2.8). CONCLUSION A single bolus dose of esmolol is an effective and safe therapeutic strategy to attenuate cardiorespiratory responses during the peri-extubation period.
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Affiliation(s)
- Fabrício Tavares Mendonça
- Hospital de Base do Distrito Federal, Centro de Ensino e Treinamento em Anestesiologia (CET), Brasília, DF, Brasil; Sociedade Brasileira de Anestesiologia, Título Superior em Anestesiologia (TSA), Rio de Janeiro, RJ, Brasil; Universidade de Brasília, Mestrado em Ciências Médicas, Brasília, DF, Brasil.
| | - Jorge Humberto Barreto Filho
- Hospital de Base do Distrito Federal, Centro de Ensino e Treinamento em Anestesiologia (CET), Brasília, DF, Brasil
| | | | - Thiago Cavalcante Magalhães
- Hospital de Base do Distrito Federal, Centro de Ensino e Treinamento em Anestesiologia (CET), Brasília, DF, Brasil
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Vice EN, Lagestee S, Browe BM, Deb D, Smith ESJ, Park TJ. Sensory Systems of the African Naked Mole-Rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:137-156. [PMID: 34424515 DOI: 10.1007/978-3-030-65943-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Naked mole-rats share some sensory characteristics with other subterraneans, including lack of object vision, retention of the ability to entrain their circadian rhythm to light, and poor hearing. On the other hand, a characteristic that may be specialized in the naked mole-rat is their exquisite orienting responses to the touch of even a single body vibrissa. They have about 100 whisker-like body vibrissae on their otherwise furless bodies. They are also insensitive to chemical and inflammatory pain, likely an adaptation to living in an atmosphere that is high in carbon dioxide, a result of many respiring individuals driving carbon dioxide accumulation. Naked mole-rats have the highest population density among subterranean mammals. High levels of carbon dioxide cause tissue acidosis and associated pain. Remarkably, naked mole-rats are completely immune to carbon dioxide-induced pulmonary edema. However, they retain the ability to detect acid as a taste (sour). Finally, their ability to smell and discriminate odors is comparable to that of rats and mice, but their vomeronasal organ, associated with sensing pheromones, is extremely small and shows a complete lack of post-natal growth. In this chapter, we review what is known about the sensory systems of the naked mole-rat with emphasis on how they differ from other mammals, and even other subterraneans. More extensive accounts of the naked mole-rat's auditory and pain systems can be found in other chapters of this book.
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Affiliation(s)
- Emily N Vice
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Samantha Lagestee
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Brigitte M Browe
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Deblina Deb
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.,Kids In Motion Pediatric Therapy Services, Highland, MI, USA
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Thomas J Park
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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15
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Sykes DL, Morice AH. The Cough Reflex: The Janus of Respiratory Medicine. Front Physiol 2021; 12:684080. [PMID: 34267675 PMCID: PMC8277195 DOI: 10.3389/fphys.2021.684080] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/09/2021] [Indexed: 01/11/2023] Open
Abstract
In clinical practice, we commonly face adversity when encountering dysfunction of the cough reflex. Similar to ancient Roman deity Janus, it often presents with one of two opposing "faces". Continual aberrant activation of the cough reflex, also known as chronic cough, can cause great detriment to quality of life and many of these patients are left misdiagnosed and undertreated. In contrast, loss of normal functioning of the cough reflex is the cause of a significant proportion of mortality in the elderly, primarily through the development of aspiration pneumonia. In this review we discuss both hyper- and hypo-activation of the cough reflex and how airway reflux and chronic aspiration may be involved in the aetiology and sequalae of both disease states. We detail the physiological and pharmacological mechanisms involved in cough, and how the recent development of P2X3 receptor antagonists may lead to the first pharmaceutical agent licensed for chronic cough. The treatment and prevention of loss of the cough reflex, which has been largely neglected, is also discussed as novel low-cost interventions could help prevent a number of hospital and domiciliary deaths from both acute and chronic aspiration.
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Affiliation(s)
- Dominic L. Sykes
- Hull University Teaching Hospitals NHS Trust, Hull, United Kingdom
| | - Alyn H. Morice
- Hull York Medical School, University of York, York, United Kingdom
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16
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Brouns I, Verckist L, Pintelon I, Timmermans JP, Adriaensen D. Pulmonary Sensory Receptors. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2021; 233:1-65. [PMID: 33950466 DOI: 10.1007/978-3-030-65817-5_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Inge Brouns
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium.
| | - Line Verckist
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Isabel Pintelon
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Dirk Adriaensen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
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17
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Elberling J. Respiratory Symptoms from Fragrances and the Link with Dermatitis. Contact Dermatitis 2021. [DOI: 10.1007/978-3-030-36335-2_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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18
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Park TJ, Smith ESJ, Reznick J, Bennett NC, Applegate DT, Larson J, Lewin GR. African Naked Mole-Rats Demonstrate Extreme Tolerance to Hypoxia and Hypercapnia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:255-269. [PMID: 34424519 DOI: 10.1007/978-3-030-65943-1_9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Naked mole-rats are extremely tolerant to low concentrations of oxygen (hypoxia) and high concentrations of carbon dioxide (hypercapnia), which is consistent with the environment that they inhabit. Naked mole-rats combine subterranean living with living in very densely populated colonies where oxygen becomes depleted and carbon dioxide accumulates. In the laboratory, naked mole-rats fully recover from 5 h exposure to 5% O2 and 5 h exposure to 80% CO2, whereas both conditions are rapidly lethal to similarly sized laboratory mice. During anoxia (0% O2) naked mole-rats enter a suspended animation-like state and switch from aerobic metabolism of glucose to anaerobic metabolism of fructose. Additional fascinating characteristics include that naked mole-rats show intrinsic brain tolerance to anoxia; a complete lack of hypoxia-induced and CO2-induced pulmonary edema; and reduced aversion to high concentrations of CO2 and acidic fumes. Here we outline a constellation of physiological and molecular adaptations that correlate with the naked mole-rat's hypoxic/hypercapnic tolerance and which offer potential targets for ameliorating pathological conditions in humans, such as the damage caused during cerebral ischemia.
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Affiliation(s)
- Thomas J Park
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - N C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel T Applegate
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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Chang YC, Cracchiolo M, Ahmed U, Mughrabi I, Gabalski A, Daytz A, Rieth L, Becker L, Datta-Chaudhuri T, Al-Abed Y, Zanos TP, Zanos S. Quantitative estimation of nerve fiber engagement by vagus nerve stimulation using physiological markers. Brain Stimul 2020; 13:1617-1630. [PMID: 32956868 DOI: 10.1016/j.brs.2020.09.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/31/2020] [Accepted: 09/04/2020] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Cervical vagus nerve stimulation (VNS) is an emerging bioelectronic treatment for brain, metabolic, cardiovascular and immune disorders. Its desired and off-target effects are mediated by different nerve fiber populations and knowledge of their engagement could guide calibration and monitoring of VNS therapies. OBJECTIVE Stimulus-evoked compound action potentials (eCAPs) directly provide fiber engagement information but are currently not feasible in humans. A method to estimate fiber engagement through common, noninvasive physiological readouts could be used in place of eCAP measurements. METHODS In anesthetized rats, we recorded eCAPs while registering acute physiological response markers to VNS: cervical electromyography (EMG), changes in heart rate (ΔHR) and breathing interval (ΔBI). Quantitative models were established to capture the relationship between A-, B- and C-fiber type activation and those markers, and to quantitatively estimate fiber activation from physiological markers and stimulation parameters. RESULTS In bivariate analyses, we found that EMG correlates with A-fiber, ΔHR with B-fiber and ΔBI with C-fiber activation, in agreement with known physiological functions of the vagus. We compiled multivariate models for quantitative estimation of fiber engagement from these markers and stimulation parameters. Finally, we compiled frequency gain models that allow estimation of fiber engagement at a wide range of VNS frequencies. Our models, after calibration in humans, could provide noninvasive estimation of fiber engagement in current and future therapeutic applications of VNS.
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Affiliation(s)
- Yao-Chuan Chang
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Marina Cracchiolo
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA; The BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pisa, 56127, Italy
| | - Umair Ahmed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Ibrahim Mughrabi
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Arielle Gabalski
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Anna Daytz
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Loren Rieth
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Lance Becker
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Timir Datta-Chaudhuri
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Yousef Al-Abed
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Theodoros P Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA
| | - Stavros Zanos
- Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Manhasset, NY, 11030, USA.
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Involvement of Capsaicin-Sensitive Lung Vagal Neurons and TRPA1 Receptors in Airway Hypersensitivity Induced by 1,3-β-D-Glucan in Anesthetized Rats. Int J Mol Sci 2020; 21:ijms21186845. [PMID: 32961891 PMCID: PMC7555683 DOI: 10.3390/ijms21186845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 12/26/2022] Open
Abstract
Airway exposure to 1,3-β-D-glucan (β-glucan), an essential component of the cell wall of several pathogenic fungi, causes various adverse responses, such as pulmonary inflammation and airway hypersensitivity. The former response has been intensively investigated; however, the mechanism underlying β-glucan-induced airway hypersensitivity is unknown. Capsaicin-sensitive lung vagal (CSLV) afferents are very chemosensitive and stimulated by various insults to the lungs. Activation of CSLV afferents triggers several airway reflexes, such as cough. Furthermore, the sensitization of these afferents is known to contribute to the airway hypersensitivity during pulmonary inflammation. This study was carried out to determine whether β-glucan induces airway hypersensitivity and the role of the CSLV neurons in this hypersensitivity. Our results showed that the intratracheal instillation of β-glucan caused not only a distinctly irregular pattern in baseline breathing, but also induced a marked enhancement in the pulmonary chemoreflex responses to capsaicin in anesthetized, spontaneously breathing rats. The potentiating effect of β-glucan was found 45 min later and persisted at 90 min. However, β-glucan no longer caused the irregular baseline breathing and the potentiating of pulmonary chemoreflex responses after treatment with perineural capsaicin treatment that blocked the conduction of CSLV fibers. Besides, the potentiating effect of β-glucan on pulmonary chemoreflex responses was significantly attenuated by N-acetyl-L-cysteine (a ROS scavenger), HC-030031 (a TRPA1 antagonist), and Laminarin (a Dectin-1 antagonist). A combination of Laminarin and HC-030031 further reduced the β-glucan-induced effect. Indeed, our fiber activity results showed that the baseline fiber activity and the sensitivity of CSLV afferents were markedly elevated by β-glucan instillation, with a similar timeframe in anesthetized, artificially ventilated rats. Moreover, this effect was reduced by treatment with HC-030031. In isolated rat CSLV neurons, the β-glucan perfusion caused a similar pattern of potentiating effects on capsaicin-induced Ca2+ transients, and β-glucan-induced sensitization was abolished by Laminarin pretreatment. Furthermore, the immunofluorescence results showed that there was a co-localization of TRPV1 and Dectin-1 expression in the DiI-labeled lung vagal neurons. These results suggest that CSLV afferents play a vital role in the airway hypersensitivity elicited by airway exposure to β-glucan. The TRPA1 and Dectin-1 receptors appear to be primarily responsible for generating β-glucan-induced airway hypersensitivity.
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Ghali MGZ. Retracted: Control of hypoglossal pre‐inspiratory discharge. Exp Physiol 2020; 105:1232-1255. [DOI: 10.1113/ep087329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 06/11/2020] [Indexed: 12/22/2022]
Affiliation(s)
- Michael George Zaki Ghali
- Departments of Neurological Surgery, Internal Medicine, General Surgery, and Neuroscience Karolinska Institutet Huddinge Stockholm Sweden
- Departments of Neurological Surgery, Neurophysiology, Neuroscience University of Oslo Oslo Norway
- Departments of Neurological Surgery and Neurochemistry University of Helsinki Helsinki Finland
- Departments of Neurological Surgery, Internal Medicine, Cardiothoracic Surgery, and Neuroscience University of California Francisco San Francisco CA USA
- Departments of Neurological Surgery and Neuroscience Barrow Neurological Institute Phoenix AZ USA
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22
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Kupari J, Häring M, Agirre E, Castelo-Branco G, Ernfors P. An Atlas of Vagal Sensory Neurons and Their Molecular Specialization. Cell Rep 2020; 27:2508-2523.e4. [PMID: 31116992 PMCID: PMC6533201 DOI: 10.1016/j.celrep.2019.04.096] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/25/2019] [Accepted: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
Sensory functions of the vagus nerve are critical for conscious perceptions and for monitoring visceral functions in the cardio-pulmonary and gastrointestinal systems. Here, we present a comprehensive identification, classification, and validation of the neuron types in the neural crest (jugular) and placode (nodose) derived vagal ganglia by single-cell RNA sequencing (scRNA-seq) transcriptomic analysis. Our results reveal major differences between neurons derived from different embryonic origins. Jugular neurons exhibit fundamental similarities to the somatosensory spinal neurons, including major types, such as C-low threshold mechanoreceptors (C-LTMRs), A-LTMRs, Aδ-nociceptors, and cold-, and mechano-heat C-nociceptors. In contrast, the nodose ganglion contains 18 distinct types dedicated to surveying the physiological state of the internal body. Our results reveal a vast diversity of vagal neuron types, including many previously unanticipated types, as well as proposed types that are consistent with chemoreceptors, nutrient detectors, baroreceptors, and stretch and volume mechanoreceptors of the respiratory, gastrointestinal, and cardiovascular systems. A comprehensive molecular identification of neuronal types in vagal ganglion complex Prdm12+ jugular ganglion neurons share features with spinal somatosensory neurons Phox2b+ viscerosensory nodose neurons are molecularly versatile and highly specialized Nodose neuron types are consistent with chemo-, baro-, stretch-, tension-, and volume-sensors
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Affiliation(s)
- Jussi Kupari
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Martin Häring
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Eneritz Agirre
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Gonçalo Castelo-Branco
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm node, Karolinska Institutet, Stockholm, Sweden
| | - Patrik Ernfors
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden.
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23
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Chung CL, Lin YS, Chan NJ, Chen YY, Hsu CC. Hypersensitivity of Airway Reflexes Induced by Hydrogen Sulfide: Role of TRPA1 Receptors. Int J Mol Sci 2020; 21:ijms21113929. [PMID: 32486252 PMCID: PMC7312894 DOI: 10.3390/ijms21113929] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 01/14/2023] Open
Abstract
The activation of capsaicin-sensitive lung vagal (CSLV) afferents can elicit airway reflexes. Hypersensitivity of these afferents is known to contribute to the airway hypersensitivity during airway inflammation. Hydrogen sulfide (H2S) has been suggested as a potential therapeutic agent for airway hypersensitivity diseases, such as asthma, because of its relaxing effect on airway smooth muscle and anti-inflammatory effect. However, it is still unknown whether H2S affects airway reflexes. Our previous study demonstrated that exogenous application of H2S sensitized CSLV afferents and enhanced Ca2+ transients in CSLV neurons. The present study aimed to determine whether the H2S-induced sensitization leads to functional changes in airway reflexes and elevates the electrical excitability of the CSLV neurons. Our results showed that, first and foremost, in anesthetized, spontaneously breathing rats, the inhalation of aerosolized sodium hydrosulfide (NaHS, a donor of H2S; 5 mg/mL, 3 min) caused an enhancement in apneic response evoked by several stimulants of the CSLV afferents. This enhancement effect was found 5 min after NaHS inhalation and returned to control 30 min later. However, NaHS no longer enhanced the apneic response after perineural capsaicin treatment on both cervical vagi that blocked the conduction of CSLV fibers. Furthermore, the enhancing effect of NaHS on apneic response was totally abolished by pretreatment with intravenous HC-030031 (a TRPA1 antagonist; 8 mg/kg), whereas the potentiating effect was not affected by the pretreatment with the vehicle of HC-030031. We also found that intracerebroventricular infusion pretreated with HC-030031 failed to alter the potentiating effect of NaHS on the apneic response. Besides, the cough reflex elicited by capsaicin aerosol was enhanced by inhalation of NaHS in conscious guinea pigs. Nevertheless, this effect was entirely eliminated by pretreatment with HC-030031, not by its vehicle. Last but not least, voltage-clamp electrophysiological analysis of isolated rat CSLV neurons showed a similar pattern of potentiating effects of NaHS on capsaicin-induced inward current, and the involvement of TRPA1 receptors was also distinctly shown. In conclusion, these results suggest that H2S non-specifically enhances the airway reflex responses, at least in part, through action on the TRPA1 receptors expressed on the CSLV afferents. Therefore, H2S should be used with caution when applying for therapeutic purposes in airway hypersensitivity diseases.
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Affiliation(s)
- Chi-Li Chung
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 110, Taiwan
- Division of Pulmonary Medicine, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - You Shuei Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (N.-J.C.); (Y.-Y.C.)
| | - Nai-Ju Chan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (N.-J.C.); (Y.-Y.C.)
| | - Yueh-Yin Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (N.-J.C.); (Y.-Y.C.)
| | - Chun-Chun Hsu
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei 110, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (N.-J.C.); (Y.-Y.C.)
- Correspondence:
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24
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Grabczak EM, Stec S, Dabrowska M, Plevkova J, Krenke R. Cough as a Cause and Consequence of Heart Dysfunction - Current State of Art. Physiol Res 2020; 69:S105-S121. [PMID: 32228016 DOI: 10.33549/physiolres.934408] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The cough reflex is an airway defensive process that can be modulated by afferent inputs from organs located also out of the respiratory system. A bidirectional relationship between cough and heart dysfunctions are presented in the article, with the special insights into an arrhythmia-triggered cough. Albeit rare, cough induced by cardiac pathologies (mainly arrhythmias) seems to be an interesting and underestimated phenomenon. This condition is usually associated with the presence of abnormal heart rhythms and ceases with successful treatment of arrhythmia either by pharmacotherapy or by radiofrequency ablation of arrhythmogenic substrate. The two main hypotheses on cough-heart relationships - reflex and hemodynamic - are discussed in the review, including the authors' perspective based on the experiences with an arrhythmia-triggered cough.
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Affiliation(s)
- E M Grabczak
- Department of Internal Medicine, Pulmonary Diseases and Allergy, University Clinical Centre, Medical University of Warsaw, Poland.
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25
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Pecova T, Kocan I, Vysehradsky R, Pecova R. Itch and Cough - Similar Role of Sensory Nerves in Their Pathogenesis. Physiol Res 2020; 69:S43-S54. [PMID: 32228011 DOI: 10.33549/physiolres.934403] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Itch is the most common chief complaint in patients visiting dermatology clinics and is analogous to cough and also sneeze of the lower and upper respiratory tract, all three of which are host actions trying to clear noxious stimuli. The pathomechanisms of these symptoms are not completely determined. The itch can originate from a variety of etiologies. Itch originates following the activation of peripheral sensory nerve endings following damage or exposure to inflammatory mediators. More than one sensory nerve subtype is thought to subservepruriceptive itch which includes both unmyelinated C-fibers and thinly myelinated Adelta nerve fibers. There are a lot of mediators capable of stimulating these afferent nerves leading to itch. Cough and itch pathways are mediated by small-diameter sensory fibers. These cough and itch sensory fibers release neuropeptides upon activation, which leads to inflammation of the nerves. The inflammation is involved in the development of chronic conditions of itch and cough. The aim of this review is to point out the role of sensory nerves in the pathogenesis of cough and itching. The common aspects of itch and cough could lead to new thoughts and perspectives in both fields.
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Affiliation(s)
- T Pecova
- Clinic of Dermatovenerology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital in Martin, Martin, Slovak
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26
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Lin AH, Hsu CC, Lin YS, Lin RL, Lee LY. Mechanisms underlying the stimulatory effect of inhaled sulfur dioxide on vagal bronchopulmonary C-fibres. J Physiol 2020; 598:1093-1108. [PMID: 31891193 DOI: 10.1113/jp279152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 12/29/2019] [Indexed: 02/05/2023] Open
Abstract
KEY POINTS Brief inhalation of SO2 of concentration >500 p.p.m. triggered a pronounced stimulatory effect on vagal bronchopulmonary C-fibres in anaesthetized rats. This stimulatory effect was drastically diminished by a pretreatment with NaHCO3 that raised the baseline arterial pH, suggesting a possible involvement of acidification of airway fluid and/or tissue generated by inhaled SO2 . The stimulation was completely abolished by pretreatment with antagonists of both acid-sensing ion channels and transient receptor potential vanilloid type-1 receptors, indicating that this effect was caused by acid activation of these cation channels expressed in airway sensory nerves. This conclusion was further supported by the results obtained from studies in isolated rat vagal bronchopulmonary sensory neurones and also in the cough response to SO2 inhalation challenge in awake mice. These results provide new insight into the underlying mechanism of harmful irritant effects in the respiratory tract caused by accidental exposure to a high concentration of SO2 . ABSTRACT Inhalation of sulfur dioxide (SO2 ) triggers coughs and reflex bronchoconstriction, and stimulation of vagal bronchopulmonary C-fibres is primarily responsible. However, the mechanism underlying this stimulatory effect is not yet fully understood. In this study, we tested the hypothesis that the C-fibre stimulation was caused by SO2 -induced local tissue acidosis in the lung and airways. Single-unit activities of bronchopulmonary C-fibres in response to inhalation challenges of SO2 (500-1500 p.p.m., 10 breaths) were measured in anaesthetized rats. Inhalation of SO2 reproducibly induced a pronounced and sustained stimulation (lasting for 15-60 s) of pulmonary C-fibres in a concentration-dependent manner. This stimulatory effect was significantly attenuated by an increase in arterial pH generated by infusion of sodium bicarbonate (NaHCO3 ), and completely abrogated by a combined pretreatment with amiloride (an antagonist of acid-sensing ion channels, ASICs) and AMG8910 (a selective antagonist of the transient receptor potential vanilloid type-1 receptor, TRPV1). Furthermore, in isolated rat vagal pulmonary sensory neurones, perfusion of an aqueous solution of SO2 evoked a transient increase in the intracellular Ca2+ concentration; this response was also markedly diminished by a pretreatment with amiloride and AMG8910. In addition, inhalation of SO2 consistently evoked coughs in awake mice; responses were significantly smaller in TRPV1-/- mice than in wild-type mice, and almost completely abolished after a pretreatment with amiloride in TRPV1-/- mice. These results suggested that the stimulatory effect of inhaled SO2 on bronchopulmonary C-fibres was generated by acidification of fluid and/or tissue in the lung and airways, which activated both ASICs and TRPV1 expressed in these sensory nerves.
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Affiliation(s)
- An-Hsuan Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
| | - Chun-Chun Hsu
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA.,School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - You Shuei Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ruei-Lung Lin
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky Medical Centre, Lexington, KY, USA
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27
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Spinelli E, Mauri T, Beitler JR, Pesenti A, Brodie D. Respiratory drive in the acute respiratory distress syndrome: pathophysiology, monitoring, and therapeutic interventions. Intensive Care Med 2020; 46:606-618. [PMID: 32016537 PMCID: PMC7224136 DOI: 10.1007/s00134-020-05942-6] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/16/2020] [Indexed: 12/18/2022]
Abstract
Neural respiratory drive, i.e., the activity of respiratory centres controlling breathing, is an overlooked physiologic variable which affects the pathophysiology and the clinical outcome of acute respiratory distress syndrome (ARDS). Spontaneous breathing may offer multiple physiologic benefits in these patients, including decreased need for sedation, preserved diaphragm activity and improved cardiovascular function. However, excessive effort to breathe due to high respiratory drive may lead to patient self-inflicted lung injury (P-SILI), even in the absence of mechanical ventilation. In the present review, we focus on the physiological and clinical implications of control of respiratory drive in ARDS patients. We summarize the main determinants of neural respiratory drive and the mechanisms involved in its potentiation, in health and ARDS. We also describe potential and pitfalls of the available bedside methods for drive assessment and explore classical and more “futuristic” interventions to control drive in ARDS patients.
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Affiliation(s)
- Elena Spinelli
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy
| | - Tommaso Mauri
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy. .,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
| | - Jeremy R Beitler
- Center for Acute Respiratory Failure, Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons/New York-Presbyterian Hospital, New York, NY, USA
| | - Antonio Pesenti
- Dipartimento di Anestesia, Rianimazione ed Emergenza-Urgenza, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Università Degli Studi Di Milano, Via F. Sforza 35, 20122, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Daniel Brodie
- Center for Acute Respiratory Failure, Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons/New York-Presbyterian Hospital, New York, NY, USA
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28
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Wei W, Gao X, Zhao L, Zhuang J, Jiao Y, Xu F. Liquiritin apioside attenuates laryngeal chemoreflex but not mechanoreflex in rat pups. Am J Physiol Lung Cell Mol Physiol 2020; 318:L89-L97. [PMID: 31617735 PMCID: PMC6985871 DOI: 10.1152/ajplung.00306.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 02/08/2023] Open
Abstract
Liquiritin apioside (LA), a main flavonoid component of licorice, reportedly suppresses cough responses to inhalation of aerosolized capsaicin [CAP; a stimulant to transient receptor potential vanilloid 1 (TRPV1)] in conscious guinea pigs via acting on peripheral nerves. However, the evidence of LA having a direct effect on airway sensory fibers is lacking. Considering the important role laryngeal chemoreceptors and mechanoreceptors play in triggering apnea and cough, we studied whether LA suppressed the apneic responses to stimulation of these receptors via directly acting on the superior laryngeal nerve (SLN). Intralaryngeal delivery of chemical [CAP, HCl, and distilled water (DW)] and mechanical [an air-pulse (AP)] stimulations was applied in anesthetized rat pups to evoke the apnea. These stimuli were repeated after intralaryngeal LA treatment or peri-SLN LA treatment to determine the direct effect of LA on the SLN. Our results showed that all stimuli triggered an immediate apnea. Intralaryngeal LA treatment significantly attenuated the apneic response to chemical but not mechanical stimulations. The same attenuation was observed after peri-SLN LA treatment. Owing that TRPV1 receptors of laryngeal C fibers are responsible for the CAP-triggered apneas, the LA impact on the activity of laryngeal C neurons retrogradely traced by DiI was subsequently studied using a patch-clamp approach. LA pretreatment significantly altered the electrophysiological kinetics of CAP-induced currents in laryngeal C neurons by reducing their amplitudes, increasing the rise times, and prolonging the decay times. In conclusion, our results, for the first time, reveal that LA suppresses the laryngeal chemoreceptor-mediated apnea by directly acting on the SLN (TRPV1 receptors of laryngeal C fibers).
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Affiliation(s)
- Wan Wei
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
- Graduate School, Beijing University of Chinese Medicine, Beijing, China
| | - Xiuping Gao
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Lei Zhao
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Jianguo Zhuang
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Yang Jiao
- Dongfang Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, China
| | - Fadi Xu
- Pathophysiology Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico
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29
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Tang CS, Chuang KJ, Chang TY, Chuang HC, Chen LH, Lung SCC, Chang LT. Effects of Personal Exposures to Micro- and Nano-Particulate Matter, Black Carbon, Particle-Bound Polycyclic Aromatic Hydrocarbons, and Carbon Monoxide on Heart Rate Variability in a Panel of Healthy Older Subjects. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16234672. [PMID: 31771182 PMCID: PMC6926945 DOI: 10.3390/ijerph16234672] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Revised: 11/12/2019] [Accepted: 11/21/2019] [Indexed: 12/14/2022]
Abstract
As a non-invasive method, heart rate variability (HRV) has been widely used to study cardiovascular autonomous control. Environmental epidemiological studies indicated that the increase in an average concentration of particulate matter (PM) would result in a decrease in HRV, which was related to the increase of cardiovascular mortality in patients with myocardial infarction and the general population. With rapid economic and social development in Asia, how air pollutants, such as PM of different sizes and their components, affect the cardiovascular health of older people, still need to be further explored. The current study includes a 72 h personal exposure monitoring of seven healthy older people who lived in the Taipei metropolitan area. Mobile equipment, a portable electrocardiogram recorder, and the generalized additive mixed model (GAMM) were adopted to evaluate how HRV indices were affected by size-fractionated PM, particle-bound polycyclic aromatic hydrocarbons (p-PAHs), black carbon (BC), and carbon monoxide (CO). Other related confounding factors, such as age, sex, body mass index (BMI), temperature, relative humidity (RH), time, and monitoring week were controlled by fixed effects of the GAMM. Statistical analyses of multi-pollutant models showed that PM2.5–10, PM1, and nanoparticle (NP) could cause heart rate (HR), time-domain indices, and frequency-domain indices to rise; PM1–2.5 and BC would cause the frequency-domain index to rise; p-PAHs would cause HR to rise, and CO would cause time-domain index and frequency-domain index to decline. In addition, the moving average time all fell after one hour and might appear at 8 h in HRVs’ largest percentage change caused by each pollutant, results of which suggested that size-fractionated PM, p-PAHs, BC, and CO exposures have delayed effects on HRVs. In conclusion, the results of the study showed that the increase in personal pollutant exposure would affect cardiac autonomic control function of healthy older residents in metropolitan areas, and the susceptibility of cardiovascular effects was higher than that of healthy young people. Since the small sample size would limit the generalizability of this study, more studies with larger scale are warranted to better understand the HRV effects of simultaneous PM and other pollution exposures for subpopulation groups.
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Affiliation(s)
- Chin-Sheng Tang
- Department of Public Health, College of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | - Kai-Jen Chuang
- School of Public Health, College of Public Health, Taipei Medical University, Taipei 11031, Taiwan
- Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Ta-Yuan Chang
- Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung 40402, Taiwan
| | - Hsiao-Chi Chuang
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
- Cell Physiology and Molecular Image Research Center, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan
- Division of Pulmonary Medicine, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan
| | - Li-Hsin Chen
- Department of Public Health, College of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan
| | | | - Li-Te Chang
- Department of Environmental Engineering and Science, Feng Chia University, Taichung 40724, Taiwan
- Correspondence: ; Tel.: +886-4-2451-7250
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30
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Zhao L, Gao X, Zhuang J, Wallen M, Leng S, Xu F. Prolongation of bronchopulmonary C-fiber-mediated apnea by prenatal nicotinic exposure in rat pups: role of 5-HT 3 receptors. FASEB J 2019; 33:10731-10741. [PMID: 31251077 PMCID: PMC6766661 DOI: 10.1096/fj.201900279rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 06/04/2019] [Indexed: 01/30/2023]
Abstract
Prenatal nicotinic exposure (PNE) reportedly sensitizes bronchopulmonary C-fibers (PCFs) and prolongs PCF-mediated apnea in rat pups, contributing to the pathogenesis of sudden infant death syndrome. Serotonin, or 5-hydroxytryptamine (5-HT), induces apnea via acting on 5-HT receptor 3 (5-HT3R) in PCFs, and among the 5-HT3R subunits, 5-HT3B is responsible for shortening the decay time of 5-HT3R-mediated currents. We examined whether PNE would promote pulmonary 5-HT secretion and prolong the apnea mediated by 5-HT3Rs in PCFs via affecting the 5-HT3B subunit. To this end, the following variables were compared between the control and PNE rat pups: 1) the 5-HT content in bronchoalveolar lavage fluid, 2) the apneic response to the right atrial bolus injection of phenylbiguanide (a 5-HT3R agonist) before and after PCF inactivation, 3) 5-HT3R currents and the stimulus threshold of the action currents of vagal pulmonary C-neurons, and 4) the immunoreactivity (IR) and mRNA expression of 5-HT3A and 5-HT3B in these neurons. Our results showed that PNE up-regulated the pulmonary 5-HT concentration and strengthened the PCF 5-HT3R-mediated apnea. PNE significantly facilitated neural excitability by shortening the decay time of 5-HT3R currents, lowering the stimulus threshold, and increasing 5-HT3B IR. In summary, PNE prolongs the apnea mediated by 5-HT3Rs in PCFs, likely by increasing 5-HT3B subunits to enhance the excitability of 5-HT3 channels.-Zhao, L., Gao, X., Zhuang, J., Wallen, M., Leng, S., Xu, F. Prolongation of bronchopulmonary C-fiber-mediated apnea by prenatal nicotinic exposure in rat pups: role of 5-HT3 receptors.
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MESH Headings
- Animals
- Animals, Newborn
- Apnea/etiology
- Apnea/genetics
- Apnea/physiopathology
- Biguanides/administration & dosage
- Bronchoalveolar Lavage Fluid/chemistry
- Disease Models, Animal
- Female
- Humans
- Infant, Newborn
- Lung/drug effects
- Lung/innervation
- Lung/physiopathology
- Male
- Nerve Fibers, Unmyelinated/drug effects
- Nerve Fibers, Unmyelinated/physiology
- Nicotine/administration & dosage
- Nicotine/toxicity
- Pregnancy
- Prenatal Exposure Delayed Effects/etiology
- Prenatal Exposure Delayed Effects/physiopathology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Serotonin, 5-HT3/genetics
- Receptors, Serotonin, 5-HT3/physiology
- Serotonin/metabolism
- Serotonin 5-HT3 Receptor Agonists/administration & dosage
- Sudden Infant Death/etiology
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Affiliation(s)
- Lei Zhao
- Pathophysiological Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA
| | - Xiuping Gao
- Pathophysiological Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA
| | - Jianguo Zhuang
- Pathophysiological Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA
| | - Morgan Wallen
- Department of Arts and Sciences, University of Tennessee, Knoxville, Tennessee, USA
| | - Shuguang Leng
- Pathophysiological Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA
| | - Fadi Xu
- Pathophysiological Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico, USA
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31
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Hsu CC, Ruan T, Lee LY, Lin YS. Stimulatory Effect of 5-Hydroxytryptamine (5-HT) on Rat Capsaicin-Sensitive Lung Vagal Sensory Neurons via Activation of 5-HT 3 Receptors. Front Physiol 2019; 10:642. [PMID: 31191346 PMCID: PMC6546846 DOI: 10.3389/fphys.2019.00642] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 05/06/2019] [Indexed: 12/13/2022] Open
Abstract
5-hydroxytryptamine (5-HT) is an inflammatory mediator known to be released in lung. Capsaicin-sensitive lung vagal (CSLV) afferents function as a primary sensor for detecting chemical stimuli and produce consequent reflexes during lung inflammation. To characterize the effect of 5-HT on CSLV afferents, responses of cardiorespiratory reflexes and single-unit C-fiber afferents to right-atrial injections of 5-HT were investigated in anesthetized Sprague-Dawley rats. Bolus injection of 5-HT (8 μg/kg) caused an immediate augmented breath and apnea, accompanied by hypotension and bradycardia. These initial responses were then followed by a brief pressor response and a more sustained depressor response. After a perineural treatment of both cervical vagi with capsaicin to block the conduction of C fibers, 5-HT still triggered the augmented breath, but no longer evoked the apnea, bradycardia and hypotension, indicating an involvement of C-fiber activation. The remaining augmented breath induced by 5-HT after perineural capsaicin treatment was totally eliminated by vagotomy. To further study the effect of 5-HT on CSLV afferents, activities arising from these afferents were determined using the single-fiber recording technique. Right-atrial injection of 5-HT evoked an intense discharge in CSLV afferents in a dose-dependent manner. The highest dose of 5-HT (16 μg/kg) activated 79% (19/24) of CSLV afferents which were also sensitive to capsaicin (0.8 μg/kg). The pretreatment of tropisetron, a selective antagonist of the 5-HT3 receptor, completely blocked CSLV-afferents stimulation induced by 5-HT but did not affect that by capsaicin. Furthermore, a similar afferent response of CSLV afferents was mimicked by phenylbiguanide, a selective agonist of the 5-HT3 receptor. In isolated rat lung vagal C neurons, 5-HT induced intense calcium transients in a dose-dependent manner. The highest concentration (3 μM) of 5-HT activated 67% (18/27) of the CSLV neurons. The 5-HT-induced response was totally abolished by pretreatment of tropisetron. In conclusion, 5-HT exerts an intense stimulatory effect on lung C-fiber terminals mediated through an activation of the 5-HT3 receptor, which may contribute to the airway hypersensitivity under lung inflammation.
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Affiliation(s)
- Chun-Chun Hsu
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan.,Department of Physiology, University of Kentucky Chandler Medical Center, Lexington, KY, United States
| | - Ting Ruan
- Department of Physiology, University of Kentucky Chandler Medical Center, Lexington, KY, United States.,School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky Chandler Medical Center, Lexington, KY, United States
| | - You Shuei Lin
- Department of Physiology, University of Kentucky Chandler Medical Center, Lexington, KY, United States.,Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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McKleroy W, Lyn-Kew K. 500 Million Alveoli from 30,000 Feet: A Brief Primer on Lung Anatomy. Methods Mol Biol 2019; 1809:3-15. [PMID: 29987778 DOI: 10.1007/978-1-4939-8570-8_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The lungs are a complex organ that fulfill multiple life-sustaining roles including transfer of oxygen and carbon dioxide between the ambient environment and the bloodstream, host defense, and immune homeostasis. As in any biological system, an understanding of the underlying anatomy is prerequisite for successful experimental design and appropriate interpretation of data, regardless of the precise experimental model or procedure in use. This chapter provides an overview of human lung anatomy focused on the airways, the ultrastructure or parenchyma of the lung, the pulmonary vasculature, the innervation of the lungs, and the pulmonary lymphatic system. We will also discuss notable anatomic differences between mouse and human lungs.
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Affiliation(s)
- William McKleroy
- Division of Pulmonary, Critical Care, and Sleep Medicine, National Jewish Health, Denver, CO, USA.,Department of Internal Medicine, University of Colorado School of Medicine, Aurora, CO, USA
| | - Kenneth Lyn-Kew
- Division of Pulmonary, Critical Care, and Sleep Medicine, National Jewish Health, Denver, CO, USA.
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33
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Lee KZ, Xu KJ. The Impact of Cervical Spinal Cord Contusion on the Laryngeal Resistance in the Rat. J Neurotrauma 2019; 36:448-459. [DOI: 10.1089/neu.2018.5798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Kun-Ze Lee
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
- Center for Neuroscience, National Sun Yat-sen University, Kaohsiung, Taiwan
- Institute of Medical Science and Technology, National Sun Yat-sen University, Kaohsiung, Taiwan
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University and Academia Sinica, Taiwan
| | - Ke-Jun Xu
- Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan
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34
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Respiratory Symptoms from Fragrances and the Link with Dermatitis. Contact Dermatitis 2019. [DOI: 10.1007/978-3-319-72451-5_23-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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35
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Slovarp LJ, Bozarth E. Altering cough reflex sensitivity with aerosolized capsaicin paired with behavioral cough suppression: a proof-of-concept study. ANNALS OF TRANSLATIONAL MEDICINE 2019; 7:7. [PMID: 30788354 DOI: 10.21037/atm.2018.12.26] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background The purpose of this prospective, quasi-experimental, single cohort proof-of-concept study was to determine feasibility and proof-of-concept of programmatically decreasing cough sensitivity through use of cough suppression strategies following inhalation of aerosolized capsaicin, in gradually increasing doses, across repeated treatment sessions. Methods Five healthy adults, ages 20-32 years of age, enrolled and completed the study. The study commenced in three phases. Phase I consisted of baseline cough sensitivity testing using pharmaceutical-grade aerosolized capsaicin, delivered via a Koko DigiDoser with nebulizer. The single-inhale, dose-response method was used. Doses that elicited two coughs (C2) and five coughs (C5) were recorded. Testing ceased when participants met the C5 threshold or when they had been given the maximum dose of 1,000 µmol/L. Phase II consisted of 5-6 treatment sessions, during which participants were exposed to increasing doses of aerosolized capsaicin while implementing behavioral cough suppression strategies. In phase III, cough sensitivity was re-tested at 1 and 3 weeks post-treatment. Participants were given explicit instructions to not try to suppress their cough. Participants who did not reach the C2 or C5 threshold at 1,000 µmol/L were assigned a score of 1,250 µmol/L. Results Each participant demonstrated a gradual increase in maximum capsaicin dose suppressed during each treatment session, with each successfully suppressing at 1,000 µmol/L by the final treatment session. C2 was greater than baseline in 4 of the 5 participants at 1 week post-treatment, and in 3 of the 5, at 3 weeks post-treatment. C5 was greater in all 5 participants at both post-treatment time points. In fact, 4 of the 5 participants did not reach the C5 threshold during either post-treatment testing sessions. Wilcoxon's Signed Rank Test, using the logC2 and logC5 values, revealed a significant difference relative to baseline in logC5 at 1 week (z=-2.02, P=0.04) and 3 weeks (z=-2.03, P=0.04) post-treatment. The difference in logC2 neared significance at 1 week post-treatment (z=-1.77, P=0.077), but was insignificant at 3 weeks post-treatment (z=-1.46, P=0.144). Conclusions This study demonstrates the potential of treating patients with refractory chronic cough (RCC), due to cough hypersensitivity, with a progressive desensitization approach paired with behavioral cough suppression. Additional research is needed using a randomized, placebo-controlled trial with patients with RCC.
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Affiliation(s)
- Laurie J Slovarp
- Department of Communicative Sciences and Disorders, The University of Montana, Missoula, MT, USA
| | - Emma Bozarth
- Department of Communicative Sciences and Disorders, The University of Montana, Missoula, MT, USA
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Du C, Kang J, Yu W, Chen M, Li B, Liu H, Wang H. Repeated exposure to temperature variation exacerbates airway inflammation through TRPA1 in a mouse model of asthma. Respirology 2018; 24:238-245. [PMID: 30440113 DOI: 10.1111/resp.13433] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/08/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND OBJECTIVE Studies from epidemiology suggest that ambient temperature is one of the underlying triggers and potential causes of asthma. The aim of this study was to examine the impact and the molecular mechanism of temperature-invoked airway inflammation using an experimental model of asthma in BALB/c mice. METHODS Mice were exposed to different temperature conditions (steady 26°C, 26°C/18°C cycle, 26°C/10°C cycle) and received sensitization and challenge of ovalbumin (OVA) during a 21-day period. HC030031, a selective transient receptor potential A1 (TRPA1) channel blocker, was used to investigate the underlying mechanism of TRPA1 in 'asthmatic' airways. After the final OVA challenge, in vivo lung function was measured, and bronchoalveolar lavage fluid (BALF) and pulmonary inflammation were assessed. RESULTS The temperature variations, especially the largest temperature difference (16°C), exacerbated airway inflammation in OVA-induced mice, increasing the levels of serum total-IgE (immunoglobulin E) and IgG1, inflammatory cells and cytokines in BALF. Analysis of histopathological changes and lung function verified that repeated exposure to very cold and changed temperatures aggravated airway hyperresponsiveness (AHR). Significant upregulation of TRPA1 expression was revealed by immunohistochemistry in the presence of the largest temperature variation (26°C/10°C cycle), while administration of HC030031 successfully inhibited TRPA1 expression, thus attenuating the asthma-like pathological features. CONCLUSION Repeated exposure to temperature variation exacerbated experimental 'asthma' and TRPA1 mediated this temperature-dependent inflammatory effect.
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Affiliation(s)
- Chenqiu Du
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.,National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China
| | - Jun Kang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Wei Yu
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.,National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China
| | - Mingqing Chen
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, China
| | - Baizhan Li
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.,National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China
| | - Hong Liu
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.,National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China
| | - Han Wang
- Joint International Research Laboratory of Green Buildings and Built Environments (Ministry of Education), Chongqing University, Chongqing, China.,National Centre for International Research of Low-Carbon and Green Buildings (Ministry of Science and Technology), Chongqing University, Chongqing, China
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Abstract
Recognizing and acting early on airway compromise reduces morbidity and mortality in patients with airway obstruction. Causes include foreign bodies, toxic/hot fumes, difficult intubation, laryngeal spasm, and tumors. Before definitive control of the airway is possible, provide 100% oxygen with a tightly fitting mask to optimize body oxygen stores. Pulse oximetry is a poor indicator of airway compromise; a decreasing arterial hemoglobin oxygen saturation is a late sign of impending hypoxemia. Basic airway maneuvers improve the patency of an obstructed airway. Getting help from an anesthetist early is a priority.
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38
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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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39
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Malaspinas I, Petak F, Baudat A, Doras C, Eigenmann PA, Habre W. Blockade of the cholinergic system during sensitization enhances lung responsiveness to allergen in rats. Clin Exp Pharmacol Physiol 2018; 45:1293-1301. [PMID: 29992592 DOI: 10.1111/1440-1681.13009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 06/18/2018] [Accepted: 06/26/2018] [Indexed: 11/27/2022]
Abstract
Although acute prophylactic administration of atropine modulates airway responsiveness, the role of the parasympathetic nervous system in the pathogenesis of sensitization and in antigen-induced bronchoconstriction remains unclear. The aim of the present study is to determine whether blocking muscarinic receptors during chronic allergen exposure modulates lung responsiveness to the specific allergen. Forty rats were randomly assigned to one of the following five treatment groups: sensitization with saline vehicle, intraperitoneal injection of ovalbumin (1 mg) with or without atropine treatment (10 mg/kg per day) and repeated ovalbumin aerosol (1.25 mg/mL for 20 minutes) either alone or combined with atropine. Lung responsiveness to methacholine (4-16 μg/kg per minute) and intravenous ovalbumin (2 mg) was established before and 21 days after treatment with forced oscillations following bilateral vagotomy. Lung cellularity was determined by analysis of bronchoalveolar lavage fluid (BALF). A lung inflammatory response in all sensitized animals was defined as an increase in the number of inflammatory cells in the BALF. Baseline respiratory mechanics and methacholine responsiveness on Days 0 and 21 were comparable in all groups. However, increases in airway resistance following intravenous allergen challenge were significantly exacerbated in rats that received atropine. Inhibition of the cholinergic nervous system during allergic sensitization potentiates bronchoconstriction following exposure to the specific allergen. These findings highlight the role of the cholinergic neuronal pathway in airway sensitization to a specific allergen.
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Affiliation(s)
- Iliona Malaspinas
- Anaesthesiological Investigation Unit, University of Geneva, Geneva, Switzerland
| | - Ferenc Petak
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Aurélie Baudat
- Anaesthesiological Investigation Unit, University of Geneva, Geneva, Switzerland
| | - Camille Doras
- Anaesthesiological Investigation Unit, University of Geneva, Geneva, Switzerland
| | - Philippe A Eigenmann
- Department of Paediatrics, Geneva Children's Hospital, University Hospital of Geneva, Geneva, Switzerland
| | - Walid Habre
- Anaesthesiological Investigation Unit, University of Geneva, Geneva, Switzerland.,Pediatric Anaesthesia Unit, Geneva Children's Hospital, University Hospitals of Geneva, Geneva, Switzerland
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40
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Lee LY, Lin RL, Khosravi M, Xu F. Reflex bronchoconstriction evoked by inhaled nicotine aerosol in guinea pigs: role of the nicotinic acetylcholine receptor. J Appl Physiol (1985) 2018; 125:117-123. [PMID: 29369741 DOI: 10.1152/japplphysiol.01039.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inhaled cigarette smoke stimulated vagal bronchopulmonary C fibers via an action of nicotine on neuronal nicotinic acetylcholine receptor (nAChR). Recent studies have reported that nicotine at high concentrations can also activate the transient receptor potential ankyrin 1 receptor (TRPA1) expressed in these sensory nerves. This study was performed to characterize the airway response to inhaled nicotine aerosol and to investigate the relative roles of nAChR and TRPA1 in this response. Guinea pigs were anesthetized and mechanically ventilated; one tidal volume of nicotine aerosol (2% solution) was diluted by an equal volume of air and delivered directly into the lung via a tracheal cannula in a single breath. Our results showed the following: 1) Inhalation of nicotine aerosol triggered an immediate and pronounced bronchoconstriction; the increase in total pulmonary resistance reached a peak of 588 ± 205% (mean ± SE) in 10-40 s, which gradually returned to baseline after 1-5 min. 2) Pretreatment with either atropine (iv) or mecamylamine (aerosol) almost completely abolished the nicotine-induced bronchoconstriction; the mecamylamine pretreatment did not block the bronchoconstriction and bradycardia evoked by electrical stimulation of the distal end of one sectioned vagus nerve, indicating its minimal systemic effects. 3) Pretreatment with HC-030031, a selective TRPA1 antagonist, abolished the bronchoconstriction induced by allyl isothiocyanate, a selective TRPA1 agonist, but did not attenuate the nicotine-evoked bronchoconstriction. In conclusion, inhalation of a single breath of nicotine aerosol evoked acute bronchoconstriction mediated through the cholinergic reflex pathway. This reflex response was triggered by activation of nAChR, but not TRPA1, located in airway sensory nerves. NEW & NOTEWORTHY Recent reports revealed that nicotine at high concentration activated transient receptor potential ankyrin 1 receptor (TRPA1) expressed in vagal bronchopulmonary sensory nerves. This study showed that inhalation of a single breath of nicotine aerosol consistently evoked acute bronchoconstriction that was mediated through the cholinergic reflex pathway and triggered by activation of nicotinic acetylcholine receptor, but not TRPA1, located in these nerves. This is new and important information considering the recent rapid and alarming rise in the prevalence of e-cigarette use for nicotine inhalation.
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Affiliation(s)
- L-Y Lee
- Department of Physiology, University of Kentucky Medical Center , Lexington, Kentucky
| | - R-L Lin
- Department of Physiology, University of Kentucky Medical Center , Lexington, Kentucky
| | - M Khosravi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Kentucky Medical Center , Lexington, Kentucky
| | - F Xu
- Lovelace Respiratory Research Institute , Albuquerque, New Mexico
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Zhang L, Sun T, Liu L, Wang L. The research of the possible mechanism and the treatment for capsaicin-induced cough. Pulm Pharmacol Ther 2017; 49:1-9. [PMID: 29288742 DOI: 10.1016/j.pupt.2017.12.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 10/18/2022]
Abstract
Unexplained chronic cough (UCC) affects millions of patients worldwide. New therapeutic approaches to this condition are urgently needed, since current treatment options provide only symptomatic relief. Cough reflex hypersensitivity has been shown to play an important role in the pathogenesis of UCC. The transient receptor potential vanilloid type 1 (TRPV1) is present on peripheral terminals of airway sensory nerves and modulation of its activity represents a potential target for the pharmacological treatment of UCC. The aim of this study was to explore the efficacy and the possible mechanism of SB705498, a TRPV1 antagonist, for cough in a capsaicin-induced cough animal model (i.e. guinea pigs). Induction of cough by capsaicin was successfully implemented in the guinea pigs, and the animals that met the inclusion criteria were randomly divided into four treatment groups: (1) Saline inhalation group (NSInh group, N = 10, negative control group), (2) Codeine phosphate intraperitoneal injection group (CPInp group, N = 10, positive control group), (3) SB705498 inhalation group (SBInh group, N = 10), (4) SB705498 intragastric administration group (SBIng group, N = 10). After treatment with above compounds, the capsaicin-induced cough experiment was performed again. The cough numbers and the cough incubation periods were recorded to evaluate the antitussive effect of SB705498. Enzyme-linked immunosorbent assay (ELISA) testing and Immunohistochemistry (IHC) staining for substance P (SP), calcitonin gene related peptide (CGRP) and neurokinin A (NKA) expression in lung and brain tissues were performed as an indication of neurogenic inflammation. Hematoxylin-Eosin (H&E) staining was used to observe the pathology morphology of lung and brain tissues. When the CPInp, SBInh and SBIng groups were compared to the NSInh group, the cough numbers were significantly reduced (p < .001), while the cough incubation periods were significantly prolonged (P < .001). In addition, the expression of SP, CGRP and NKA in lung and brain tissue was reduced (P < .05). None of the animals in the four groups exhibited lung and brain parenchymal inflammation. The results from this study showed that SB705498 had a significant antitussive effect, could reduce the neurogenic inflammation by reducing the expression of SP, CGRP and NKA in a capsaicin-induced cough model of guinea pigs. The results further indicated that TRPV1 played an important role in UCC and SB705498 might be a promising therapeutic agent for UCC.
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Affiliation(s)
- Li Zhang
- Department of Respiratory and Critical Care Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China; Peking University, The Fifth School of Clinical Medicine, Beijing, China.
| | - Tieying Sun
- Department of Respiratory and Critical Care Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China; Peking University, The Fifth School of Clinical Medicine, Beijing, China.
| | - Longteng Liu
- Peking University, The Fifth School of Clinical Medicine, Beijing, China; Department of Pathology, Beijing Hospital, National Center of Gerontology, Beijing, China.
| | - Lifang Wang
- Department of Respiratory and Critical Care Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China; Peking University, The Fifth School of Clinical Medicine, Beijing, China.
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42
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Abstract
Syncope can result from certain activities that trigger an exaggerated physiological response in susceptible individuals; examples include cough, laugh, and micturition syncope. We report a novel cause for syncope, that due to reflex bradycardia and asystole produced by the use of asthma inhalers. We discuss the possible mechanisms for this effect and briefly review other breathing-related causes of bradycardia.
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Affiliation(s)
- Robert L Rosenthal
- Division of Cardiology, Baylor Heart and Vascular Hospital, Dallas, Texas
| | - Jay O Franklin
- Division of Cardiology, Baylor Heart and Vascular Hospital, Dallas, Texas
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43
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Vencloviene J, Braziene A, Dedele A, Lopatiene K, Dobozinskas P. Associations of short-term exposure to ambient air pollutants with emergency ambulance calls for the exacerbation of essential arterial hypertension. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2017; 27:509-524. [PMID: 29149802 DOI: 10.1080/09603123.2017.1405246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/23/2017] [Indexed: 06/07/2023]
Abstract
We investigated the association between daily emergency ambulance calls (EAC) for elevated blood pressure that occurred during the time intervals of 8:00-13:59, 14:00-21:59, and 22:00-7:59, and exposure to CO, PM10, and ozone. We used Poisson regression to explore the association between the risk of EAC and short-term variation of pollutants, adjusting for seasonality and weather variables. Before noon, the risk was associated with an interquartile range (IQR) (7.9 μg/m3) increase in PM10 at lag 2-4 days below the median (RR = 1.08, p = 0.031) and with an IQR (0.146 mg/m3) increase in CO at lag 6-7 below the median (RR = 1.05, p = 0.028). During 14:00-21:59, the risk was associated with an IQR (18.8 μg/m3) increase in PM10 on the previous day below the median (RR = 1.04, p = 0.031). At night, EAC were negatively affected by lower O3 (lag 0-2) below the median (per IQR decrease RR = 1.10, p = 0.018) and a higher PM10 at lag 0-1 above the median for the elderly (RR = 1.07, p = 0.030).
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Affiliation(s)
- Jone Vencloviene
- a Department of Environmental Sciences , Vytautas Magnus University , Kaunas , Lithuania
| | - Agne Braziene
- a Department of Environmental Sciences , Vytautas Magnus University , Kaunas , Lithuania
| | - Audrius Dedele
- a Department of Environmental Sciences , Vytautas Magnus University , Kaunas , Lithuania
| | - Kristina Lopatiene
- b Department of Orthodontics , Lithuanian University of Health Sciences , Kaunas , Lithuania
| | - Paulius Dobozinskas
- c Department of Disaster Medicine , Lithuanian University of Health Sciences , Kaunas , Lithuania
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Wasilewski NV, Fisher T, Turcotte SE, Fisher JT, Lougheed MD. Bronchoprotective effect of deep inspirations in cough variant asthma: A distinguishing feature in the spectrum of airway disease? Respir Physiol Neurobiol 2017; 257:55-64. [PMID: 28917529 DOI: 10.1016/j.resp.2017.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/30/2017] [Accepted: 09/06/2017] [Indexed: 11/18/2022]
Abstract
PURPOSE To assess the effect of deep inspirations (DIs) on airway behaviour in individuals with classic asthma (CA), cough variant asthma (CVA), and methacholine (MCh)-induced cough but normal airway sensitivity (COUGH) during bronchoprovocation. METHODS Twenty-five adults (18 female; 44.8 ± 12.3 years (Mean ± SD); n = 9 CA, n = 9 CVA, and n = 7 COUGH) completed two single-dose MCh challenges, with and without DIs. Bronchoprotection was assessed by comparing changes in bronchoconstriction (FEV1, FVC, FEV1/FVC, FEF50, FEF25-75), gas trapping (RV, RV/TLC) and impulse oscillometry (IOS) measurements. RESULTS The% changes in FEV1 with and without DIs were not significantly different within any group. Decreases in FEF50 and FEF25-75 were greater in CA (p = 0.041 and p = 0.029), decreases in FVC (% predicted) and FEV1/FVC(%) were less in CVA (p = 0.048 and p = 0.010), and increases in RV (L) and RV/TLC (% predicted) were less in COUGH (p = 0.007 and p = 0.028), respectively. No differences in IOS measurements were noted. CONCLUSIONS DIs triggered bronchoconstriction in CA, bronchoprotection in CVA, and prevented gas trapping in COUGH.
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Affiliation(s)
- Nastasia V Wasilewski
- Department of Medicine, Kingston General Hospital and Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Thomas Fisher
- Department of Medicine, Kingston General Hospital and Queen's University, Kingston, ON, Canada
| | - Scott E Turcotte
- Department of Medicine, Kingston General Hospital and Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - John T Fisher
- Department of Medicine, Kingston General Hospital and Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - M Diane Lougheed
- Department of Medicine, Kingston General Hospital and Queen's University, Kingston, ON, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
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45
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Brainstem mechanisms underlying the cough reflex and its regulation. Respir Physiol Neurobiol 2017; 243:60-76. [DOI: 10.1016/j.resp.2017.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 12/12/2022]
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Lin RL, Gu Q, Lee LY. Hypersensitivity of Vagal Pulmonary Afferents Induced by Tumor Necrosis Factor Alpha in Mice. Front Physiol 2017; 8:411. [PMID: 28659824 PMCID: PMC5470033 DOI: 10.3389/fphys.2017.00411] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 05/30/2017] [Indexed: 12/31/2022] Open
Abstract
Tumor necrosis factor alpha (TNFα), a pro-inflammatory cytokine, plays a significant role in the pathogenesis of allergic asthma. Inhalation of TNFα also induces airway hyperresponsiveness in healthy human subjects, and the underlying mechanism is not fully understood. A recent study reported that TNFα caused airway inflammation and a sustained elevation of pulmonary chemoreflex responses in mice, suggesting a possible involvement of heightened sensitivity of vagal pulmonary C-fibers. To investigate this possibility, the present study aimed to investigate the effect of a pretreatment with TNFα on the sensitivity of vagal pulmonary afferents in anesthetized mice. After TNFα (10 μg/ml, 0.03 ml) and vehicle (Veh; phosphate buffered saline (PBS), 0.03 ml) were administered by intra-tracheal instillation in each mouse of treated (TNF) and control (Veh) groups, respectively, the peak activity of pulmonary C-fibers in response to an intravenous bolus injection of a low dose of capsaicin (Cap; 0.5 μg/kg) was significantly elevated in TNF group (6.5 ± 1.3 impulses/s, n = 12) 24–48 h later, compared to that in Veh group (2.2 ± 0.5 impulses/s, n = 11; P < 0.05). Interestingly, the same low dose of Cap injection also evoked a distinct burst of discharge (2.4 ± 0.7 impulses/s) in 75% of the silent rapidly adapting receptors (RARs), a subtype of RARs exhibiting no phasic activity, in TNF group, but did not stimulate any of the silent RARs in Veh group. To further determine if this sensitizing effect involves a direct action of TNFα on these sensory nerves, the change in intracellular Ca2+ concentration in response to Cap challenge was measured in isolated mouse vagal pulmonary sensory neurons. The Cap-evoked Ca2+ influx was markedly enhanced in the neurons incubated with TNFα (50 ng/ml) for ~24 h, and this sensitizing effect was attenuated in the neurons isolated from the TNF-receptor double homozygous mutant mice. In conclusion, the TNFα pretreatment enhanced the Cap sensitivity in both pulmonary C-fibers and silent RARs, and the action was mediated through TNF receptors. These sensitizing effects of TNFα may contribute, at least in part, to the pathogenesis of airway hyperresponsiveness induced by this cytokine.
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Affiliation(s)
- Ruei-Lung Lin
- Department of Physiology, University of Kentucky, Lexington, KY, United States
| | - Qihai Gu
- Department of Biomedical Sciences, Mercer University, Macon, GA, United States
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky, Lexington, KY, United States
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Lin RL, Gu Q, Khosravi M, Lee LY. Sustained sensitizing effects of tumor necrosis factor alpha on sensory nerves in lung and airways. Pulm Pharmacol Ther 2017; 47:29-37. [PMID: 28587842 DOI: 10.1016/j.pupt.2017.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 05/30/2017] [Accepted: 06/03/2017] [Indexed: 01/07/2023]
Abstract
Tumor necrosis factor alpha (TNFα) plays a significant role in the pathogenesis of airway inflammatory diseases. Inhalation of aerosolized TNFα induced airway hyperresponsiveness accompanied by airway inflammation in healthy human subjects, but the underlying mechanism is not fully understood. We recently reported a series of studies aimed to investigate if TNFα elevates the sensitivity of vagal bronchopulmonary sensory nerves in a mouse model; these studies are summarized in this mini-review. Our results showed that intratracheal instillation of TNFα induced pronounced airway inflammation 24 h later, as illustrated by infiltration of eosinophils and neutrophils and the release of inflammatory mediators and cytokines in the lung and airways. Accompanying these inflammatory reactions, the sensitivity of vagal pulmonary C-fibers and silent rapidly adapting receptors to capsaicin, a selective agonist of transient receptor potential vanilloid type 1 receptor, was markedly elevated after the TNFα treatment. A distinct increase in the sensitivity to capsaicin induced by TNFα was also observed in isolated pulmonary sensory neurons, suggesting that the sensitizing effect is mediated primarily through a direct action of TNFα on these neurons. Furthermore, the same TNFα treatment also induced a lingering (>7days) cough hyperresponsiveness to inhalation challenge of NH3 in awake mice. Both the airway inflammation and the sensitizing effect on pulmonary sensory neurons caused by the TNFα treatment were abolished in the TNF-receptor double homozygous mutant mice, indicating the involvement of TNF-receptor activation. These findings suggest that the TNFα-induced hypersensitivity of vagal bronchopulmonary afferents may be responsible for, at least in part, the airway hyperresponsiveness caused by inhaled TNFα in healthy individuals.
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Affiliation(s)
- Ruei-Lung Lin
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Qihai Gu
- Department of Biomedical Sciences, Mercer University, Macon, GA, USA
| | - Mehdi Khosravi
- Department of Medicine, University of Kentucky, Lexington, KY, USA
| | - Lu-Yuan Lee
- Department of Physiology, University of Kentucky, Lexington, KY, USA.
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Nault S, Samson N, Nadeau C, Djeddi D, Praud JP. Reflex cardiorespiratory events from esophageal origin are heightened by preterm birth. J Appl Physiol (1985) 2017; 123:489-497. [PMID: 28572501 DOI: 10.1152/japplphysiol.00915.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 05/08/2017] [Accepted: 05/24/2017] [Indexed: 12/19/2022] Open
Abstract
The involvement of gastroesophageal refluxes in cardiorespiratory events of preterm infants remains controversial. While a few studies in full-term newborn animals have shown that stimulation of esophageal receptors leads to cardiorespiratory reflexes, the latter remain largely unknown, especially after premature birth. The present study aimed to 1) characterize the cardiorespiratory reflexes originating from esophageal receptors in newborn lambs and 2) test the hypotheses that preterm birth enhances reflex cardiorespiratory inhibition and that C-fibers are involved in these reflexes. Eight full-term lambs and 10 lambs born 14 days prematurely were studied. Following surgical instrumentation, a 6-h polysomnography was performed without sedation to record electrocardiogram, respiratory movements, arterial pressure, laryngeal constrictor muscle activity, state of alertness, and hemoglobin oxygen saturation. Five esophageal stimulations of the upper and/or lower esophagus, including rapid balloon inflation and/or HCl injection, were performed in random order. A second recording was performed in full-term lambs 24 h later, after C-fiber blockade by capsaicin. Results confirmed that esophageal stimulations induced inhibitory cardiorespiratory reflexes combined with protective mechanisms, including laryngeal closure, swallowing, coughing, increased arterial pressure, and arousal. Preterm birth heightened cardiorespiratory inhibition. The strongest cardiorespiratory inhibition was observed following simultaneous stimulation of the lower and upper esophagus. Finally, cardiorespiratory inhibition was decreased after C-fiber blockade. In conclusion, esophageal stimulation induces inhibitory cardiorespiratory reflexes, which are partly mediated by C-fibers and more pronounced in preterm lambs. Clinical relevance of these findings requires further studies, especially in conditions associated with increased cardiorespiratory events, e.g., neonatal infection.NEW & NOTEWORTHY Preterm birth heightens the cardiorespiratory events triggered by esophageal stimulation. The most extensive cardiorespiratory events are induced by simultaneous stimulation of the proximal and distal esophagus.
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Affiliation(s)
- Stéphanie Nault
- Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology, Université de Sherbrooke, Quebec, Canada; and
| | - Nathalie Samson
- Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology, Université de Sherbrooke, Quebec, Canada; and
| | - Charlène Nadeau
- Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology, Université de Sherbrooke, Quebec, Canada; and
| | - Djamal Djeddi
- Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology, Université de Sherbrooke, Quebec, Canada; and.,Department of Pediatrics, Université de Picardie Jules Verne, Amiens, France
| | - Jean-Paul Praud
- Neonatal Respiratory Research Unit, Departments of Pediatrics and Pharmacology-Physiology, Université de Sherbrooke, Quebec, Canada; and
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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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Mikami M, Zhang Y, Kim B, Worgall TS, Groeben H, Emala CW. Dexmedetomidine's inhibitory effects on acetylcholine release from cholinergic nerves in guinea pig trachea: a mechanism that accounts for its clinical benefit during airway irritation. BMC Anesthesiol 2017; 17:52. [PMID: 28356076 PMCID: PMC5372301 DOI: 10.1186/s12871-017-0345-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Airway instrumentation can evoke upper airway reflexes including bronchoconstriction and cough which can cause serious complications including airway trauma, laryngospasm or bronchospasm which may in turn lead to difficulty with ventilation and hypoxemia. These airway events are mediated in part by irritant-induced neuronal modulation of airway tone and cough responses. We investigated whether the commonly used anesthetic agents dexmedetomidine, lidocaine or remifentanil attenuated neuronal and airway smooth muscle responses in the upper airways of guinea pigs. METHODS The ability of dexmedetomidine, lidocaine or remifentanil to attenuate direct cholinergic nerve stimulation, C-fiber stimulation or direct smooth muscle contraction were studied using isolated tracheal rings from male guinea pigs under four paradigms; (1) the magnitude of contractile force elicited by cholinergic electrical field stimulation (EFS); (2) the amount of acetylcholine released during cholinergic EFS; (3) the direct airway smooth muscle relaxation of a sustained acetylcholine-induced contraction and (4) the magnitude of C-fiber mediated contraction. RESULTS Dexmedetomidine (1-100 μM) and lidocaine (1 mM) attenuated cholinergic 30Hz EFS-induced tracheal ring contraction while remifentanil (10 μM) had no effect. Dexmedetomidine at 10 μM (p = 0.0047) and 100 μM (p = 0.01) reduced cholinergic EFS-induced acetylcholine release while lidocaine (10 μM-1 mM) and remifentanil (0.1-10 μM) did not. Tracheal ring muscle force induced by the exogenous addition of the contractile agonist acetylcholine or by a prototypical C-fiber analogue of capsaicin were also attenuated by 100 μM dexmedetomidine (p = 0.0061 and p = 0.01, respectively). The actual tracheal tissue concentrations of dexmedetomidine achieved (0.54-26 nM) following buffer application of 1-100 μM of dexmedetomidine were within the range of clinically achieved plasma concentrations (12 nM). CONCLUSIONS The α2 adrenoceptor agonist dexmedetomidine reduced cholinergic EFS-induced contractions and acetylcholine release consistent with the presence of inhibitory α2 adrenoceptors on the prejunctional side of the postganglionic cholinergic nerve-smooth muscle junction. Dexmedetomidine also attenuated both exogenous acetylcholine-induced contraction and C-fiber mediated contraction, suggesting a direct airway smooth muscle effect and an underlying mechanism for cough suppression, respectively.
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Affiliation(s)
- Maya Mikami
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, 630 West 168th Street, P&S Box 46, New York, NY, 10032, USA.
| | - Yi Zhang
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, 630 West 168th Street, P&S Box 46, New York, NY, 10032, USA
| | - Benjamin Kim
- Department of Pathology and Cell Biology, College of Physicians and Surgeons of Columbia University, New York, NY, USA
| | - Tilla S Worgall
- Department of Pathology and Cell Biology, College of Physicians and Surgeons of Columbia University, New York, NY, USA
| | - Harald Groeben
- Department of Anesthesiology, Intensive Care and Pain Therapy, Kliniken Essen-Mitte, Essen, Germany
| | - Charles W Emala
- Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, 630 West 168th Street, P&S Box 46, New York, NY, 10032, USA
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