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Guedes MR, de Noronha SISR, Chírico MTT, da Costa GDC, de Freitas Castro T, de Brito RCF, Vieira LG, Reis TO, Ribeiro MC, Reis AB, Carneiro CM, Bezerra FS, Montano N, da Silva VJD, de Menezes RCA, Chianca-Jr DA, Silva FCDS. Ivabradine restores tonic cardiovascular autonomic control and reduces tachycardia, hypertension and left ventricular inflammation in post-weaning protein malnourished rats. Life Sci 2024; 346:122636. [PMID: 38614307 DOI: 10.1016/j.lfs.2024.122636] [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: 01/25/2024] [Revised: 03/22/2024] [Accepted: 04/10/2024] [Indexed: 04/15/2024]
Abstract
Malnutrition results in autonomic imbalance and heart hypertrophy. Overexpression of hyperpolarization-activated cyclic nucleotide-gated channels (HCN) in the left ventricles (LV) is linked to hypertrophied hearts and abnormal myocardium automaticity. Given that ivabradine (IVA) has emerging pleiotropic effects, in addition to the widely known bradycardic response, this study evaluated if IVA treatment could repair the autonomic control and cardiac damages in malnourished rats. AIM Assess the impact of IVA on tonic cardiovascular autonomic control and its relationship with hemodynamics regulation, LV inflammation, and HCN gene expression in post-weaning protein malnutrition condition. MAIN METHODS After weaning, male rats were divided into control (CG; 22 % protein) and malnourished (MG; 6 % protein) groups. At 35 days, groups were subdivided into CG-PBS, CG-IVA, MG-PBS and MG-IVA (PBS 1 ml/kg or IVA 1 mg/kg) received during 8 days. We performed jugular vein cannulation and electrode implant for drug delivery and ECG registration to assess tonic cardiovascular autonomic control; femoral cannulation for blood pressure (BP) and heart rate (HR) assessment; and LV collection to evaluate ventricular remodeling and HCN gene expression investigation. KEY FINDINGS Malnutrition induced BP and HR increases, sympathetic system dominance, and LV remodeling without affecting HCN gene expression. IVA reversed the cardiovascular autonomic imbalance; prevented hypertension and tachycardia; and inhibited the LV inflammatory process and fiber thickening caused by malnutrition. SIGNIFICANCE Our findings suggest that ivabradine protects against malnutrition-mediated cardiovascular damage. Moreover, our results propose these effects were not attributed to HCN expression changes, but rather to IVA pleiotropic effects on autonomic control and inflammation.
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Affiliation(s)
- Mariana Reis Guedes
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Sylvana Izaura Salyba Rendeiro de Noronha
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Máira Tereza Talma Chírico
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Gabriela Dias Carvalho da Costa
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Thalles de Freitas Castro
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Rory Cristiane Fortes de Brito
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Lucas Gabriel Vieira
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Thayane Oliveira Reis
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Marcelo Carlos Ribeiro
- Statistics Department, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Alexandre Barbosa Reis
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Cláudia Martins Carneiro
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Frank Silva Bezerra
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Nicola Montano
- Department of Clinical Sciences and Community Health, IRCCS Ca' Granda Foundation, Ospedale Maggiore Policlinico, University of Milan, Milan, Italy.
| | - Valdo José Dias da Silva
- Department of Biochemistry, Pharmacology and Physiology, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil; Graduate Program in Physiological Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil.
| | - Rodrigo Cunha Alvim de Menezes
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Deoclécio Alves Chianca-Jr
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
| | - Fernanda Cacilda Dos Santos Silva
- Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil; Graduate Program in Biological Sciences - CBIOL/NUPEB, Federal University of Ouro Preto, Ouro Preto, Brazil.
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2
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Lataro RM, Brognara F, Iturriaga R, Paton JFR. Inflammation of some visceral sensory systems and autonomic dysfunction in cardiovascular disease. Auton Neurosci 2024; 251:103137. [PMID: 38104365 DOI: 10.1016/j.autneu.2023.103137] [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: 07/27/2023] [Revised: 11/15/2023] [Accepted: 12/04/2023] [Indexed: 12/19/2023]
Abstract
The sensitization and hypertonicity of visceral afferents are highly relevant to the development and progression of cardiovascular and respiratory disease states. In this review, we described the evidence that the inflammatory process regulates visceral afferent sensitivity and tonicity, affecting the control of the cardiovascular and respiratory system. Some inflammatory mediators like nitric oxide, angiotensin II, endothelin-1, and arginine vasopressin may inhibit baroreceptor afferents and contribute to the baroreflex impairment observed in cardiovascular diseases. Cytokines may act directly on peripheral afferent terminals that transmit information to the central nervous system (CNS). TLR-4 receptors, which recognize lipopolysaccharide, were identified in the nodose and petrosal ganglion and have been implicated in disrupting the blood-brain barrier, which can potentiate the inflammatory process. For example, cytokines may cross the blood-brain barrier to access the CNS. Additionally, pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α and some of their receptors have been identified in the nodose ganglion and carotid body. These pro-inflammatory cytokines also sensitize the dorsal root ganglion or are released in the nucleus of the solitary tract. In cardiovascular disease, pro-inflammatory mediators increase in the brain, heart, vessels, and plasma and may act locally or systemically to activate/sensitize afferent nervous terminals. Recent evidence demonstrated that the carotid body chemoreceptor cells might sense systemic pro-inflammatory molecules, supporting the novel proposal that the carotid body is part of the afferent pathway in the central anti-inflammatory reflexes. The exact mechanisms of how pro-inflammatory mediators affects visceral afferent signals and contribute to the pathophysiology of cardiovascular diseases awaits future research.
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Affiliation(s)
- R M Lataro
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil.
| | - F Brognara
- Department of Nursing, General and Specialized, Nursing School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - R Iturriaga
- Facultad de Ciencias Biológicas, Pontificia Universidad Catolica de Chile, Santiago, Chile; Centro de Investigación en Fisiología y Medicina en Altura - FIMEDALT, Universidad de Antofagasta, Antofagasta, Chile
| | - J F R Paton
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Grafton, Auckland, New Zealand
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3
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Tsai SF, Kuo YM. The Role of Central Oxytocin in Autonomic Regulation. CHINESE J PHYSIOL 2024; 67:3-14. [PMID: 38780268 DOI: 10.4103/ejpi.ejpi-d-23-00037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/10/2023] [Indexed: 05/25/2024] Open
Abstract
Oxytocin (OXT), a neuropeptide originating from the hypothalamus and traditionally associated with peripheral functions in parturition and lactation, has emerged as a pivotal player in the central regulation of the autonomic nervous system (ANS). This comprehensive ANS, comprising sympathetic, parasympathetic, and enteric components, intricately combines sympathetic and parasympathetic influences to provide unified control. The central oversight of sympathetic and parasympathetic outputs involves a network of interconnected regions spanning the neuroaxis, playing a pivotal role in the real-time regulation of visceral function, homeostasis, and adaptation to challenges. This review unveils the significant involvement of the central OXT system in modulating autonomic functions, shedding light on diverse subpopulations of OXT neurons within the paraventricular nucleus of the hypothalamus and their intricate projections. The narrative progresses from the basics of central ANS regulation to a detailed discussion of the central controls of sympathetic and parasympathetic outflows. The subsequent segment focuses specifically on the central OXT system, providing a foundation for exploring the central role of OXT in ANS regulation. This review synthesizes current knowledge, paving the way for future research endeavors to unravel the full scope of autonomic control and understand multifaceted impact of OXT on physiological outcomes.
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Affiliation(s)
- Sheng-Feng Tsai
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yu-Min Kuo
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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4
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Afonso AI, Amaro-Leal Â, Machado F, Rocha I, Geraldes V. Doxorubicin Dose-Dependent Impact on Physiological Balance-A Holistic Approach in a Rat Model. BIOLOGY 2023; 12:1031. [PMID: 37508460 PMCID: PMC10376408 DOI: 10.3390/biology12071031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023]
Abstract
Doxorubicin (DOX) is commonly used in several chemotherapies to treat various cancers, but it is known to cause cardiotoxicity and cardiac symptoms. Autonomic dysfunction is thought to contribute to the cardiotoxic effects of DOX, but the specific dose required to disrupt homeostatic processes is still unclear and is influenced by numerous factors. This study aimed to investigate how the DOX dosage affects autonomic function and physiological parameters, to elucidate the neurocardiac mechanisms underlying the observed cardiovascular side effects. Wistar rats were treated with DOX for four weeks and divided into three dosing groups: DOX8 (2 mg/kg/week), DOX16 (4 mg/kg/week), and DOX20 (5 mg/kg/week). A control group received NaCl 0.9% saline (1 mL/kg/week). In an acute experiment, we recorded blood pressure (BP), electrocardiogram, heart rate (HR), and respiratory rate (RF). Baroreflex gain and chemoreflex sensitivity were calculated, and cardiac tissue was analyzed with picrosirius histochemistry to measure collagen content. Our results showed that the LF/HF ratio, indicative of autonomic activity, was altered along with hypotension and bradycardia at a cumulative DOX dose threshold of 16 mg/kg. We observed a positive correlation between DOX dose and BP, HR, urinary norepinephrine, LF/HF ratio, and fibrotic heart area. Lower LF/HF ratios were associated with high DOX doses, reflecting drug-induced impairment of autonomic control of HR. This study provides valuable insights into the dose-dependent effects of DOX on physiological parameters and the development of cardiovascular dysfunction. These findings are critical, which is important for optimizing the management and therapeutic strategies for patients undergoing DOX-based chemotherapy.
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Affiliation(s)
- Ana I Afonso
- Cardiovascular Centre of the University of Lisbon, 1649-028 Lisbon, Portugal
| | - Ângela Amaro-Leal
- Cardiovascular Centre of the University of Lisbon, 1649-028 Lisbon, Portugal
- Egas Moniz School of Health and Science, 2829-511 Caparica, Portugal
| | - Filipa Machado
- Cardiovascular Centre of the University of Lisbon, 1649-028 Lisbon, Portugal
| | - Isabel Rocha
- Cardiovascular Centre of the University of Lisbon, 1649-028 Lisbon, Portugal
- Institute of Physiology, Faculty of Medicine of the University of Lisbon, 1649-028 Lisbon, Portugal
| | - Vera Geraldes
- Cardiovascular Centre of the University of Lisbon, 1649-028 Lisbon, Portugal
- Institute of Physiology, Faculty of Medicine of the University of Lisbon, 1649-028 Lisbon, Portugal
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5
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Giannoni A, Borrelli C, Gentile F, Sciarrone P, Spießhöfer J, Piepoli M, Richerson GB, Floras JS, Coats AJS, Javaheri S, Emdin M, Passino C. Autonomic and respiratory consequences of altered chemoreflex function: clinical and therapeutic implications in cardiovascular diseases. Eur J Heart Fail 2023; 25:642-656. [PMID: 36907827 PMCID: PMC10989193 DOI: 10.1002/ejhf.2819] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 02/10/2023] [Accepted: 02/26/2023] [Indexed: 03/14/2023] Open
Abstract
The importance of chemoreflex function for cardiovascular health is increasingly recognized in clinical practice. The physiological function of the chemoreflex is to constantly adjust ventilation and circulatory control to match respiratory gases to metabolism. This is achieved in a highly integrated fashion with the baroreflex and the ergoreflex. The functionality of chemoreceptors is altered in cardiovascular diseases, causing unstable ventilation and apnoeas and promoting sympathovagal imbalance, and it is associated with arrhythmias and fatal cardiorespiratory events. In the last few years, opportunities to desensitize hyperactive chemoreceptors have emerged as potential options for treatment of hypertension and heart failure. This review summarizes up to date evidence of chemoreflex physiology/pathophysiology, highlighting the clinical significance of chemoreflex dysfunction, and lists the latest proof of concept studies based on modulation of the chemoreflex as a novel target in cardiovascular diseases.
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Affiliation(s)
- Alberto Giannoni
- Health Science Interdisciplinary Center, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana G. Monasterio, Pisa, Italy
| | | | - Francesco Gentile
- Health Science Interdisciplinary Center, Scuola Superiore Sant’Anna, Pisa, Italy
| | | | - Jens Spießhöfer
- Health Science Interdisciplinary Center, Scuola Superiore Sant’Anna, Pisa, Italy
- University of Aachen, Aachen, Germany
| | | | | | - John S Floras
- Division of Cardiology, Mount Sinai Hospital, University of Toronto, Ontario, Canada
| | | | - Shahrokh Javaheri
- Division of Pulmonary and Sleep Medicine, Bethesda North Hospital, Cincinnati, Ohio, Division of Pulmonary, Critical Care and Sleep Medicine, University of Cincinnati, Cincinnati, Ohio, and Division of Cardiology, The Ohio State University, Columbus, Ohio USA
| | - Michele Emdin
- Health Science Interdisciplinary Center, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana G. Monasterio, Pisa, Italy
| | - Claudio Passino
- Health Science Interdisciplinary Center, Scuola Superiore Sant’Anna, Pisa, Italy
- Fondazione Toscana G. Monasterio, Pisa, Italy
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6
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Lataro RM, Moraes DJA, Gava FN, Omoto ACM, Silva CAA, Brognara F, Alflen L, Brazão V, Colato RP, do Prado JC, Ford AP, Salgado HC, Paton JFR. P2X3 receptor antagonism attenuates the progression of heart failure. Nat Commun 2023; 14:1725. [PMID: 36977675 PMCID: PMC10050083 DOI: 10.1038/s41467-023-37077-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/02/2023] [Indexed: 03/30/2023] Open
Abstract
Despite advances in the treatment of heart failure, prognosis is poor, mortality high and there remains no cure. Heart failure is associated with reduced cardiac pump function, autonomic dysregulation, systemic inflammation and sleep-disordered breathing; these morbidities are exacerbated by peripheral chemoreceptor dysfunction. We reveal that in heart failure the carotid body generates spontaneous, episodic burst discharges coincident with the onset of disordered breathing in male rats. Purinergic (P2X3) receptors were upregulated two-fold in peripheral chemosensory afferents in heart failure, and when antagonized abolished these episodic discharges, normalized both peripheral chemoreceptor sensitivity and the breathing pattern, reinstated autonomic balance, improved cardiac function, and reduced both inflammation and biomarkers of cardiac failure. Aberrant ATP transmission in the carotid body triggers episodic discharges that via P2X3 receptors play a crucial role in the progression of heart failure and as such offer a distinct therapeutic angle to reverse multiple components of its pathogenesis.
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Affiliation(s)
- Renata M Lataro
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Davi J A Moraes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Fabio N Gava
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
- Department of Clinical Veterinary, Agrarian Sciences Center, Londrina State University, Londrina, Brazil
| | - Ana C M Omoto
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Carlos A A Silva
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Fernanda Brognara
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Lais Alflen
- Department of Physiological Sciences, Center of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Vânia Brazão
- College of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Rafaela Pravato Colato
- College of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - José Clóvis do Prado
- College of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Julian F R Paton
- Manaaki Manawa-The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand.
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7
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Ou YH, Tan A, Lee CH. Management of hypertension in obstructive sleep apnea. Am J Prev Cardiol 2023; 13:100475. [PMID: 36873802 PMCID: PMC9976208 DOI: 10.1016/j.ajpc.2023.100475] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 02/08/2023] [Accepted: 02/12/2023] [Indexed: 02/17/2023] Open
Abstract
Obstructive sleep apnea (OSA) plays an important role in the development of hypertension. Thus, this review summarizes pharmacological and non-pharmacological approaches to blood pressure (BP) control in patients with OSA. Current treatments for OSA, such as continuous positive airway pressure, are effective at lowering BP. However, they only provide a modest BP reduction, and pharmacological treatment remains important for achieving optimal BP control. Furthermore, current guidelines for the treatment of hypertension do not make specific recommendations on pharmacological treatment protocols for controlling BP in patients with OSA. Moreover, the BP-lowering effects of various classes of antihypertensives may be different in hypertensive patients with OSA than in those without OSA due to the underlying mechanisms that promote hypertension in OSA. The acute and chronic increase in sympathetic nerve activity in patients with OSA explain the effectiveness of beta blockers in controlling BP in these patients. As activation of the renin-angiotensin-aldosterone system may also promote hypertension in OSA, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have generally been found effective for lowering BP in hypertensive patients with OSA. The aldosterone antagonist spironolactone also produces a good antihypertensive response in patients with OSA and resistant hypertension. However, there are limited data available that compare the effects of various classes of antihypertensive medication on BP control in those with OSA, and most data have been obtained from small-scale studies. This demonstrates the need for large-scale randomized controlled trials to evaluate a range of BP-lowering regimens in patients with OSA and hypertension.
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Affiliation(s)
- Yi-Hui Ou
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Adeline Tan
- Department of Respiratory Medicine, Ng Teng Fong General Hospital, Singapore
| | - Chi-Hang Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Department of Cardiology, National University Heart Centre Singapore, Singapore
- Cardiovascular Research Institute, National University of Singapore, Singapore
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8
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Yang H, Tenorio Lopes L, Barioni NO, Roeske J, Incognito AV, Baker J, Raj SR, Wilson RJA. The molecular makeup of peripheral and central baroreceptors: stretching a role for Transient Receptor Potential (TRP), Epithelial Sodium Channel (ENaC), Acid Sensing Ion Channel (ASIC), and Piezo channels. Cardiovasc Res 2022; 118:3052-3070. [PMID: 34734981 DOI: 10.1093/cvr/cvab334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/27/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
The autonomic nervous system maintains homeostasis of cardiovascular, respiratory, gastrointestinal, urinary, immune, and thermoregulatory function. Homeostasis involves a variety of feedback mechanisms involving peripheral afferents, many of which contain molecular receptors sensitive to mechanical deformation, termed mechanosensors. Here, we focus on the molecular identity of mechanosensors involved in the baroreflex control of the cardiovascular system. Located within the walls of the aortic arch and carotid sinuses, and/or astrocytes in the brain, these mechanosensors are essential for the rapid moment-to-moment feedback regulation of blood pressure (BP). Growing evidence suggests that these mechanosensors form a co-existing system of peripheral and central baroreflexes. Despite the importance of these molecules in cardiovascular disease and decades of research, their precise molecular identity remains elusive. The uncertainty surrounding the identity of these mechanosensors presents a major challenge in understanding basic baroreceptor function and has hindered the development of novel therapeutic targets for conditions with known arterial baroreflex impairments. Therefore, the purpose of this review is to (i) provide a brief overview of arterial and central baroreflex control of BP, (ii) review classes of ion channels currently proposed as the baroreflex mechanosensor, namely Transient Receptor Potential (TRP), Epithelial Sodium Channel (ENaC), Acid Sensing Ion Channel (ASIC), and Piezo, along with additional molecular candidates that serve mechanotransduction in other organ systems, and (iii) summarize the potential clinical implications of impaired baroreceptor function in the pathophysiology of cardiovascular disease.
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Affiliation(s)
- Hannah Yang
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Luana Tenorio Lopes
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Nicole O Barioni
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Jamie Roeske
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Anthony V Incognito
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Jacquie Baker
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
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9
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A Methodological Perspective on the Function and Assessment of Peripheral Chemoreceptors in Heart Failure: A Review of Data from Clinical Trials. Biomolecules 2022; 12:biom12121758. [PMID: 36551186 PMCID: PMC9775522 DOI: 10.3390/biom12121758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 11/22/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
Augmented peripheral chemoreceptor sensitivity (PChS) is a common feature of many sympathetically mediated diseases, among others, and it is an important mechanism of the pathophysiology of heart failure (HF). It is related not only to the greater severity of symptoms, especially to dyspnea and lower exercise tolerance but also to a greater prevalence of complications and poor prognosis. The causes, mechanisms, and impact of the enhanced activity of peripheral chemoreceptors (PChR) in the HF population are subject to intense research. Several methodologies have been established and utilized to assess the PChR function. Each of them presents certain advantages and limitations. Furthermore, numerous factors could influence and modulate the response from PChR in studied subjects. Nevertheless, even with the impressive number of studies conducted in this field, there are still some gaps in knowledge that require further research. We performed a review of all clinical trials in HF human patients, in which the function of PChR was evaluated. This review provides an extensive synthesis of studies evaluating PChR function in the HF human population, including methods used, factors potentially influencing the results, and predictors of increased PChS.
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Li YL. Stellate Ganglia and Cardiac Sympathetic Overactivation in Heart Failure. Int J Mol Sci 2022; 23:ijms232113311. [PMID: 36362099 PMCID: PMC9653702 DOI: 10.3390/ijms232113311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 11/06/2022] Open
Abstract
Heart failure (HF) is a major public health problem worldwide, especially coronary heart disease (myocardial infarction)-induced HF with reduced ejection fraction (HFrEF), which accounts for over 50% of all HF cases. An estimated 6 million American adults have HF. As a major feature of HF, cardiac sympathetic overactivation triggers arrhythmias and sudden cardiac death, which accounts for nearly 50–60% of mortality in HF patients. Regulation of cardiac sympathetic activation is highly integrated by the regulatory circuitry at multiple levels, including afferent, central, and efferent components of the sympathetic nervous system. Much evidence, from other investigators and us, has confirmed the afferent and central neural mechanisms causing sympathoexcitation in HF. The stellate ganglion is a peripheral sympathetic ganglion formed by the fusion of the 7th cervical and 1st thoracic sympathetic ganglion. As the efferent component of the sympathetic nervous system, cardiac postganglionic sympathetic neurons located in stellate ganglia provide local neural coordination independent of higher brain centers. Structural and functional impairments of cardiac postganglionic sympathetic neurons can be involved in cardiac sympathetic overactivation in HF because normally, many effects of the cardiac sympathetic nervous system on cardiac function are mediated via neurotransmitters (e.g., norepinephrine) released from cardiac postganglionic sympathetic neurons innervating the heart. This review provides an overview of cardiac sympathetic remodeling in stellate ganglia and potential mechanisms and the role of cardiac sympathetic remodeling in cardiac sympathetic overactivation and arrhythmias in HF. Targeting cardiac sympathetic remodeling in stellate ganglia could be a therapeutic strategy against malignant cardiac arrhythmias in HF.
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Affiliation(s)
- Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA; ; Tel.: +1-402-559-3016; Fax: +1-402-559-9659
- Department of Cellular & Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198, USA
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11
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Katayama PL, Leirão IP, Kanashiro A, Menani JV, Zoccal DB, Colombari DSA, Colombari E. The carotid body: A novel key player in neuroimmune interactions. Front Immunol 2022; 13:1033774. [PMID: 36389846 PMCID: PMC9644854 DOI: 10.3389/fimmu.2022.1033774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
The idea that the nervous system communicates with the immune system to regulate physiological and pathological processes is not new. However, there is still much to learn about how these interactions occur under different conditions. The carotid body (CB) is a sensory organ located in the neck, classically known as the primary sensor of the oxygen (O2) levels in the organism of mammals. When the partial pressure of O2 in the arterial blood falls, the CB alerts the brain which coordinates cardiorespiratory responses to ensure adequate O2 supply to all tissues and organs in the body. A growing body of evidence, however, has demonstrated that the CB is much more than an O2 sensor. Actually, the CB is a multimodal sensor with the extraordinary ability to detect a wide diversity of circulating molecules in the arterial blood, including inflammatory mediators. In this review, we introduce the literature supporting the role of the CB as a critical component of neuroimmune interactions. Based on ours and other studies, we propose a novel neuroimmune pathway in which the CB acts as a sensor of circulating inflammatory mediators and, in conditions of systemic inflammation, recruits a sympathetic-mediated counteracting mechanism that appears to be a protective response.
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Affiliation(s)
- Pedro L. Katayama
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Isabela P. Leirão
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Alexandre Kanashiro
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - José V. Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Daniel B. Zoccal
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Débora S. A. Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
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Huang J, McDonnell BJ, Lawley JS, Byrd J, Stöhr EJ, Cornwell WK. Impact of Mechanical Circulatory Support on Exercise Capacity in Patients With Advanced Heart Failure. Exerc Sport Sci Rev 2022; 50:222-229. [PMID: 36095073 PMCID: PMC9475848 DOI: 10.1249/jes.0000000000000303] [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] [Indexed: 11/21/2022]
Abstract
Approximately 6 million individuals have heart failure in the United States alone and 15 million in Europe. Left ventricular assist devices (LVAD) improve survival in these patients, but functional capacity may not fully improve. This article examines the hypothesis that patients supported by LVAD experience persistent reductions in functional capacity and explores mechanisms accounting for abnormalities in exercise tolerance.
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Affiliation(s)
- Janice Huang
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
| | - Barry J. McDonnell
- School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff UK
| | - Justin S. Lawley
- Department of Sport Science, University of Innsbruck, Innsbruck Austria
| | - Jessica Byrd
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
| | - Eric J. Stöhr
- Faculty of Philosophical Sciences, Institute of Sport Science, Leibniz University Hannover, Hannover, Germany
- Department of Medicine, Division of Cardiology, Columbia University Irving Medical Center, New York City, NY, USA
| | - William K. Cornwell
- Department of Medicine-Cardiology. University of Colorado Anschutz Medical Campus, Aurora CO
- Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora CO
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13
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Zhao C, Li C, Zhao B, Liu Y. Expression of group II and III mGluRs in the carotid body and its role in the carotid chemoreceptor response to acute hypoxia. Front Physiol 2022; 13:1008073. [PMID: 36213225 PMCID: PMC9536148 DOI: 10.3389/fphys.2022.1008073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
The carotid body (CB) contributes significantly to oxygen sensing. It is unclear, however, whether glutamatergic signaling is involved in the CB response to hypoxia. Previously, we reported that ionotropic glutamate receptors (iGluRs) and multiple glutamate transporters are present in the rat CB. Except for iGluRs, glutamate receptors also include metabotropic glutamate receptors (mGluRs), which are divided into the following groups: Group I (mGluR1/5); group II (mGluR2/3); group III (mGluR4/6/7/8). We have studied the expression of group I mGluRs in the rat CB and its physiological function response to acute hypoxia. To further elucidate the states of mGluRs in the CB, this study’s aim was to investigate the expression of group II and III mGluRs and the response of rat CB to acute hypoxia. We used reverse transcription-polymerase chain reaction (RT-PCR) to observed mRNA expression of GRM2/3/4/6/7/8 subunits by using immunostaining to show the distribution of mGluR2 and mGluR8. The results revealed that the GRM2/3/4/6/7/8 mRNAs were expressed in both rat and human CB. Immunostaining showed that mGluR2 was localized in the type I cells and mGluR8 was localized in type I and type II cells in the rat CB. Moreover, the response of CB to acute hypoxia in rats was recorded by in vitro carotid sinus nerve (CSN) discharge. Perfusion of group II mGluRs agonist or group III mGluRs agonist (LY379268 or L-SOP) was applied to examine the effect of group II and III mGluRs on rat CB response to acute hypoxia. We found that LY379268 and L-SOP inhibited hypoxia-induced enhancement of CSN activity. Based on the above findings, group II and III mGluRs appear to play an inhibitory role in the carotid chemoreceptor response to acute hypoxia.
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Affiliation(s)
- Chenlu Zhao
- Henan Key Laboratory of Neurorestoratology, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
| | - Chaohong Li
- Henan Key Laboratory of Neurorestoratology, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
| | - Baosheng Zhao
- Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
| | - Yuzhen Liu
- Henan Key Laboratory of Neurorestoratology, Life Science Research Center, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
- Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
- *Correspondence: Yuzhen Liu,
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PRAKASCHANDRA DR, NAIDOO DP. Association of cardio-metabolic risk factors with elevated basal heart rate in South African Asian Indians. Minerva Endocrinol (Torino) 2022; 47:295-303. [DOI: 10.23736/s2724-6507.20.03246-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Kulej-Lyko K, Niewinski P, Tubek S, Krawczyk M, Kosmala W, Ponikowski P. Inhibition of peripheral chemoreceptors improves ventilatory efficiency during exercise in heart failure with preserved ejection fraction − a role of tonic activity and acute reflex response. Front Physiol 2022; 13:911636. [PMID: 36111161 PMCID: PMC9470150 DOI: 10.3389/fphys.2022.911636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/19/2022] [Indexed: 11/22/2022] Open
Abstract
Peripheral chemoreceptors (PChRs) play a significant role in maintaining adequate oxygenation in the bloodstream. PChRs functionality comprises two components: tonic activity (PChT) which regulates ventilation during normoxia and acute reflex response (peripheral chemosensitivity, PChS), which increases ventilation following a specific stimulus. There is a clear link between augmented PChS and exercise intolerance in patients with heart failure with reduced ejection fraction. It has been also shown that inhibition of PChRs leads to the improvement in exercise capacity. However, it has not been established yet: 1) whether similar mechanisms take part in heart failure with preserved ejection fraction (HFpEF) and 2) which component of PChRs functionality (PChT vs. PChS) is responsible for the benefit seen after the acute experimental blockade. To answer those questions we enrolled 12 stable patients with HFpEF. All participants underwent an assessment of PChT (attenuation of minute ventilation in response to low-dose dopamine infusion), PChS (enhancement of minute ventilation in response to hypoxia) and a symptom-limited cardiopulmonary exercise test on cycle ergometer. All tests were placebo-controlled, double-blinded and performed in a randomized order. Under resting conditions and at normoxia dopamine attenuated minute ventilation and systemic vascular resistance (p = 0.03 for both). These changes were not seen with placebo. Dopamine also decreased ventilatory and mean arterial pressure responses to hypoxia (p < 0.05 for both). Inhibition of PChRs led to a decrease in V˙E/V˙CO2 comparing to placebo (36 ± 3.6 vs. 34.3 ± 3.7, p = 0.04), with no effect on peak oxygen consumption. We found a significant relationship between PChT and the relative decrement of V˙E/V˙CO2 on dopamine comparing to placebo (R = 0.76, p = 0.005). There was a trend for correlation between PChS (on placebo) and V˙E/V˙CO2 during placebo infusion (R = 0.56, p = 0.059), but the relative improvement in V˙E/V˙CO2 was not related to the change in PChS (dopamine vs. placebo). We did not find a significant relationship between PChT and PChS. In conclusion, inhibition of PChRs in HFpEF population improves ventilatory efficiency during exercise. Increased PChS is associated with worse (higher) V˙E/V˙CO2, whereas PChT predicts an improvement in V˙E/V˙CO2 after PChRs inhibition. This results may be meaningful for patient selection in further clinical trials involving PChRs modulation.
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Affiliation(s)
- Katarzyna Kulej-Lyko
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Department of Cardiology, University Clinical Hospital, Wroclaw, Poland
- *Correspondence: Katarzyna Kulej-Lyko,
| | - Piotr Niewinski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Department of Cardiology, University Clinical Hospital, Wroclaw, Poland
| | - Stanislaw Tubek
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Department of Cardiology, University Clinical Hospital, Wroclaw, Poland
| | | | - Wojciech Kosmala
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Department of Cardiology, University Clinical Hospital, Wroclaw, Poland
| | - Piotr Ponikowski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Department of Cardiology, University Clinical Hospital, Wroclaw, Poland
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Burtscher J, Niedermeier M, Hüfner K, van den Burg E, Kopp M, Stoop R, Burtscher M, Gatterer H, Millet GP. The interplay of hypoxic and mental stress: Implications for anxiety and depressive disorders. Neurosci Biobehav Rev 2022; 138:104718. [PMID: 35661753 DOI: 10.1016/j.neubiorev.2022.104718] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 12/14/2022]
Abstract
Adequate oxygen supply is essential for the human brain to meet its high energy demands. Therefore, elaborate molecular and systemic mechanism are in place to enable adaptation to low oxygen availability. Anxiety and depressive disorders are characterized by alterations in brain oxygen metabolism and of its components, such as mitochondria or hypoxia inducible factor (HIF)-pathways. Conversely, sensitivity and tolerance to hypoxia may depend on parameters of mental stress and the severity of anxiety and depressive disorders. Here we discuss relevant mechanisms of adaptations to hypoxia, as well as their involvement in mental stress and the etiopathogenesis of anxiety and depressive disorders. We suggest that mechanisms of adaptations to hypoxia (including metabolic responses, inflammation, and the activation of chemosensitive brain regions) modulate and are modulated by stress-related pathways and associated psychiatric diseases. While severe chronic hypoxia or dysfunctional hypoxia adaptations can contribute to the pathogenesis of anxiety and depressive disorders, harnessing controlled responses to hypoxia to increase cellular and psychological resilience emerges as a novel treatment strategy for these diseases.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Martin Niedermeier
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Clinic for Psychiatry II, Innsbruck Medical University, Innsbruck, Austria
| | - Erwin van den Burg
- Department of Psychiatry, Center of Psychiatric Neuroscience (CNP), University Hospital of Lausanne (CHUV), Prilly, Lausanne, Switzerland
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Ron Stoop
- Department of Psychiatry, Center of Psychiatric Neuroscience (CNP), University Hospital of Lausanne (CHUV), Prilly, Lausanne, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
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17
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Langner-Hetmańczuk A, Tubek S, Niewiński P, Ponikowski P. The Role of Pharmacological Treatment in the Chemoreflex Modulation. Front Physiol 2022; 13:912616. [PMID: 35774285 PMCID: PMC9237514 DOI: 10.3389/fphys.2022.912616] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/19/2022] [Indexed: 12/20/2022] Open
Abstract
From a physiological point of view, peripheral chemoreceptors (PCh) are the main sensors of hypoxia in mammals and are responsible for adaptation to hypoxic conditions. Their stimulation causes hyperventilation—to increase oxygen uptake and increases sympathetic output in order to counteract hypoxia-induced vasodilatation and redistribute the oxygenated blood to critical organs. While this reaction promotes survival in acute settings it may be devastating when long-lasting. The permanent overfunctionality of PCh is one of the etiologic factors and is responsible for the progression of sympathetically-mediated diseases. Thus, the deactivation of PCh has been proposed as a treatment method for these disorders. We review here physiological background and current knowledge regarding the influence of widely prescribed medications on PCh acute and tonic activities.
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Affiliation(s)
- Anna Langner-Hetmańczuk
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland
| | - Stanisław Tubek
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland
- *Correspondence: Stanisław Tubek,
| | - Piotr Niewiński
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland
| | - Piotr Ponikowski
- Institute of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
- Institute of Heart Diseases, University Hospital, Wroclaw, Poland
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18
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Agbor VN, Chen Y, Clarke R, Guo Y, Pei P, Lv J, Yu C, Li L, Chen Z, Bennett D. Resting heart rate and risk of left and right heart failure in 0.5 million Chinese adults. Open Heart 2022; 9:e001963. [PMID: 35649571 PMCID: PMC9161067 DOI: 10.1136/openhrt-2022-001963] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 05/09/2022] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To compare the shape and strength of the associations of resting heart rate (RHR) with incident heart failure (HF) and pulmonary heart disease (PHD) in Chinese adults. METHODS The prospective China Kadoorie Biobank recruited >0.5 million adults from 10 geographically diverse regions (5 urban, 5 rural) of China during 2004-2008. After an 11-year follow-up, 6082 incident cases of HF and 5572 cases of PHD, were recorded among 491 785 participants with no prior history of heart disease or use of beta-blockers at baseline. Cox regression yielded HRs for each disease associated with usual RHR after adjustment for confounding factors. RESULTS The mean (SD) baseline RHR was 79 (12) (men 78 (12); women 80 (11)) bpm, and these decreased with increasing age (by about 1 bpm per 10 years). Usual RHR showed J-shaped associations with HF and log-linear associations PHD. For HF, each 10 bpm higher usual RHR was associated with an adjusted HR of 1.25 (95% CI 1.17 to 1.34) for RHR>75 bpm. For PHD, each 10 bpm higher RHR was associated with HR of 1.74 (1.67-1.81) across the full range of usual RHR. For HF at RHR>75 bpm but not PHD, the HRs per 10 bpm higher RHR were approximately halved by further adjustment for diabetes and hypertension. CONCLUSIONS RHR was strongly positively associated with PHD throughout the range studied, but was only associated with HF at RHR>75 bpm, and the strength of the associations with HF were only one-third of those with PHD.
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Affiliation(s)
- Valirie Ndip Agbor
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Yiping Chen
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- Medical Research Council, Population Health Research Unit (PHRU), University of Oxford, Oxford, UK
| | - Robert Clarke
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- Medical Research Council, Population Health Research Unit (PHRU), University of Oxford, Oxford, UK
| | - Yu Guo
- National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College Fuwai Hospital, Xicheng District, Beijing, China
| | - Pei Pei
- National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College Fuwai Hospital, Xicheng District, Beijing, China
| | - Jun Lv
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China
- Centre for Public Health and Epidemic Preparedness and Response, Peking University, Beijing, China
| | - Canqing Yu
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China
- Centre for Public Health and Epidemic Preparedness and Response, Peking University, Beijing, China
| | - Liming Li
- Department of Epidemiology and Biostatistics, School of Public Health, Peking University Health Science Center, Beijing, China
- Centre for Public Health and Epidemic Preparedness and Response, Peking University, Beijing, China
| | - Zhengming Chen
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- Medical Research Council, Population Health Research Unit (PHRU), University of Oxford, Oxford, UK
| | - Derrick Bennett
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- Medical Research Council, Population Health Research Unit (PHRU), University of Oxford, Oxford, UK
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19
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Katayama PL, Leirão IP, Kanashiro A, Luiz JPM, Cunha FQ, Navegantes LCC, Menani JV, Zoccal DB, Colombari DSA, Colombari E. The carotid body detects circulating tumor necrosis factor-alpha to activate a sympathetic anti-inflammatory reflex. Brain Behav Immun 2022; 102:370-386. [PMID: 35339628 DOI: 10.1016/j.bbi.2022.03.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/10/2022] [Accepted: 03/21/2022] [Indexed: 12/28/2022] Open
Abstract
Recent evidence has suggested that the carotid bodies might act as immunological sensors, detecting pro-inflammatory mediators and signalling to the central nervous system, which, in turn, orchestrates autonomic responses. Here, we confirmed that the TNF-α receptor type I is expressed in the carotid bodies of rats. The systemic administration of TNF-α increased carotid body afferent discharge and activated glutamatergic neurons in the nucleus tractus solitarius (NTS) that project to the rostral ventrolateral medulla (RVLM), where many pre-sympathetic neurons reside. The activation of these neurons was accompanied by an increase in splanchnic sympathetic nerve activity. Carotid body ablation blunted the TNF-α-induced activation of RVLM-projecting NTS neurons and the increase in splanchnic sympathetic nerve activity. Finally, plasma and spleen levels of cytokines after TNF-α administration were higher in rats subjected to either carotid body ablation or splanchnic sympathetic denervation. Collectively, our findings indicate that the carotid body detects circulating TNF-α to activate a counteracting sympathetic anti-inflammatory mechanism.
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Affiliation(s)
- Pedro L Katayama
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil.
| | - Isabela P Leirão
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Alexandre Kanashiro
- Department of Neurosciences and Behavior, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - João P M Luiz
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Fernando Q Cunha
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Luiz C C Navegantes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Jose V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Daniel B Zoccal
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil.
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20
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Toledo C, Ortolani D, Ortiz FC, Marcus NJ, Del Rio R. Potential Role of the Retrotrapezoid Nucleus in Mediating Cardio-Respiratory Dysfunction in Heart Failure With Preserved Ejection Fraction. Front Physiol 2022; 13:863963. [PMID: 35492622 PMCID: PMC9039230 DOI: 10.3389/fphys.2022.863963] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 03/29/2022] [Indexed: 01/15/2023] Open
Abstract
A strong association between chemoreflex hypersensitivity, disordered breathing, and elevated sympathetic activity has been shown in experimental and human heart failure (HF). The contribution of chemoreflex hypersensitivity in HF pathophysiology is incompletely understood. There is ample evidence that increased peripheral chemoreflex drive in HF with reduced ejection fraction (HFrEF; EF<40%) leads to pathophysiological changes in autonomic and cardio-respiratory control, but less is known about the neural mechanisms mediating cardio-respiratory disturbances in HF with preserved EF (HFpEF; EF>50%). Importantly, it has been shown that activation of the central chemoreflex worsens autonomic dysfunction in experimental HFpEF, an effect mediated in part by the activation of C1 catecholaminergic neurons neighboring the retrotrapezoid nucleus (RTN), an important region for central chemoreflex control of respiratory and autonomic function. Accordingly, the main purpose of this brief review is to discuss the possible role played by activation of central chemoreflex pathways on autonomic function and its potential role in precipitating disordered breathing in HFpEF. Improving understanding of the contribution of the central chemoreflex to the pathophysiology of HFpEF may help in development of novel interventions intended to improve cardio-respiratory outcomes in HFpEF.
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Affiliation(s)
- Camilo Toledo
- Laboratory Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
| | - Domiziana Ortolani
- Laboratory Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Fernando C. Ortiz
- Mechanisms of Myelin Formation and Repair Laboratory, Facultad de Ciencias de Salud, Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Noah J. Marcus
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, IA, United States
| | - Rodrigo Del Rio
- Laboratory Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
- Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
- *Correspondence: Rodrigo Del Rio,
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21
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Nalini YC, Basavarajegowda A. Syncopal reactions in blood donors: Pathophysiology, clinical course, and features. Asian J Transfus Sci 2022. [DOI: 10.4103/ajts.ajts_167_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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22
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Yu TY, Hong W, Jin S, Hur KY, Jee JH, Bae JC, Kim JH, Lee M. Delayed heart rate recovery after exercise predicts development of metabolic syndrome: A retrospective cohort study. J Diabetes Investig 2022; 13:167-176. [PMID: 34313016 PMCID: PMC8756310 DOI: 10.1111/jdi.13637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 07/16/2021] [Accepted: 07/22/2021] [Indexed: 12/20/2022] Open
Abstract
AIMS/INTRODUCTION Several cross-sectional studies have shown that delayed heart rate recovery (HRR) after exercise is associated with the development of metabolic syndrome (MetS). However, there has been a lack of comprehensively designed longitudinal studies. Therefore, our aim was to evaluate the longitudinal association of delayed HRR following a graded exercise treadmill test (GTX) with incident MetS. MATERIALS AND METHODS This was a retrospective longitudinal cohort study of participants without MetS, diabetes, or cardiovascular diseases. The HRR was calculated as the peak heart rate minus the resting heart rate after a 1 min rest (HRR1), a 2 min rest (HRR2), and a 3 min rest (HRR3). Multivariate Cox proportional hazards analysis was performed to investigate the association between HRR and development of MetS. RESULTS There were 676 (31.2%) incident cases of MetS identified during the follow-up period (9,683 person-years). The only statistically significant relationship was between HRR3 and the development of MetS. The hazard ratios (HRs) (95% confidence interval [CI]) of incident MetS comparing the first and second tertiles to the third tertile of HRR3 were 1.492 (1.146-1.943) and 1.277 (1.004-1.624) with P = 0.003 after adjustment for multiple risk factors. As a continuous variable, the HR (95% CI) of incident MetS associated with each one-beat decrease in HRR3 was 1.015 (1.005-1.026) with P = 0.004 after full adjustments. An HRR3 value ≤45 beats per minute (bpm) was associated with a higher risk of incident MetS compared with values >45 bpm, with an HR (95% CI) of 1.304 (1.061-1.602) and P = 0.001. CONCLUSIONS The slow phase of HRR, particularly HRR3, might be more sensitive at predicting the risk of MetS.
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Affiliation(s)
- Tae Yang Yu
- Division of Endocrinology and MetabolismDepartment of MedicineWonkwang Medical CenterWonkwang University School of MedicineIksanKorea
- Department of MedicineSungkyunkwan University Graduate School of MedicineSeoulKorea
| | - Won‐Jung Hong
- Division of Endocrinology and MetabolismDepartment of MedicineSamsung Medical CenterSungkyunkwan University School of MedicineSeoulKorea
| | - Sang‐Man Jin
- Division of Endocrinology and MetabolismDepartment of MedicineSamsung Medical CenterSungkyunkwan University School of MedicineSeoulKorea
| | - Kyu Yeon Hur
- Division of Endocrinology and MetabolismDepartment of MedicineSamsung Medical CenterSungkyunkwan University School of MedicineSeoulKorea
| | - Jae Hwan Jee
- Department of Health Promotion CenterSamsung Medical CenterSungkyunkwan University School of MedicineSeoulKorea
| | - Ji Cheol Bae
- Division of Endocrinology and MetabolismDepartment of MedicineSamsung Changwon HospitalSungkyunkwan University School of MedicineChangwonKorea
| | - Jae Hyeon Kim
- Division of Endocrinology and MetabolismDepartment of MedicineSamsung Medical CenterSungkyunkwan University School of MedicineSeoulKorea
| | - Moon‐Kyu Lee
- Division of Endocrinology and MetabolismDepartment of Internal MedicineUijeongbu Eulji Medical CenterEulji University School of MedicineUijeongbuKorea
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23
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Li L, Hu Z, Xiong Y, Yao Y. Device-Based Sympathetic Nerve Regulation for Cardiovascular Diseases. Front Cardiovasc Med 2021; 8:803984. [PMID: 34957267 PMCID: PMC8695731 DOI: 10.3389/fcvm.2021.803984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/22/2021] [Indexed: 12/05/2022] Open
Abstract
Sympathetic overactivation plays an important role in promoting a variety of pathophysiological processes in cardiovascular diseases (CVDs), including ventricular remodeling, vascular endothelial injury and atherosclerotic plaque progression. Device-based sympathetic nerve (SN) regulation offers a new therapeutic option for some CVDs. Renal denervation (RDN) is the most well-documented method of device-based SN regulation in clinical studies, and several large-scale randomized controlled trials have confirmed its value in patients with resistant hypertension, and some studies have also found RDN to be effective in the control of heart failure and arrhythmias. Pulmonary artery denervation (PADN) has been clinically shown to be effective in controlling pulmonary hypertension. Hepatic artery denervation (HADN) and splenic artery denervation (SADN) are relatively novel approaches that hold promise for a role in cardiovascular metabolic and inflammatory-immune related diseases, and their first-in-man studies are ongoing. In addition, baroreflex activation, spinal cord stimulation and other device-based therapies also show favorable outcomes. This review summarizes the pathophysiological rationale and the latest clinical evidence for device-based therapies for some CVDs.
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Affiliation(s)
| | | | | | - Yan Yao
- National Center for Cardiovascular Diseases, Peking Union Medical College, Chinese Academy of Medical Sciences, Fu Wai Hospital, Beijing, China
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24
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Effect of Renal Denervation on Cardiac Function and Inflammatory Factors in Heart Failure After Myocardial Infarction. J Cardiovasc Pharmacol 2021; 76:602-609. [PMID: 32868626 PMCID: PMC7641177 DOI: 10.1097/fjc.0000000000000899] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is Available in the Text. Heart failure (HF) affects around 100 million people and is a staggering burden for health care system worldwide. Rapid and sustained activation of inflammatory response is an important feature of HF after myocardial infarction. Sympathetic overactivation is also an important factor in the occurrence and progression of HF. The beneficial effect of renal denervation (RDN) has been demonstrated in HF. In the current study, we hypothesized that RDN improves cardiac function in HF canine models due to acute myocardial infarction (AMI) and reduced inflammation might be involved. Twenty-four beagles were randomized into the control (n = 8), HF (n = 8), and HF + RDN group (n = 8). The HF model after AMI was established by embolization the anterior descending distal artery with anhydrous ethanol in the HF and HF + RDN group. Bilateral renal artery ablation was performed in the HF + RDN group. Cardiac function, serum creatine kinase, creatine kinase-MB and NT-Pro BNP level, and expression of inflammation-related proteins in myocardial were examined. Because the paraventricular nucleus of the hypothalamus might be involved in inflammation-induced central neural excitation in HF and plays an important role in regulating extracellular fluid volume and sympathetic activity, expression of inflammation-related proteins in hypothalamus was also examined. AMI and post-AMI HF model was created successfully. Compared with the HF group, dogs in the HF + RDN group showed better cardiac function 4 weeks after AMI: lower left ventricular end-diastolic pressure, left ventricular end-diastolic dimension, and left ventricular end-systolic dimension and higher LEVF and left ventricular systolic pressure (P < 0.05 for all) were observed in the HF + RDN group. In addition, dogs in the HF + RDN group had slightly less ventricular fibrosis. Interestingly, RDN had lower expression of inflammation-related proteins including interleukin-6, tumor necrosis factors-α, nuclear factor κB, and monocyte chemotactic protein 1 (P < 0.05 for all) in both myocardial tissue and hypothalamus. RDN can improve cardiac function in dogs with HF after myocardial infarction. Our results suggested that RDN might affect cytokine-induced central neural excitation in HF and later affect sympathetic activity. Our results suggested a potential beneficial mechanism of RDN independent of mechanism involving renal afferent and efferent sympathetic nerves.
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25
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Mineralocorticoid receptor blockade normalizes coronary resistance in obese swine independent of functional alterations in K v channels. Basic Res Cardiol 2021; 116:35. [PMID: 34018061 DOI: 10.1007/s00395-021-00879-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
Impaired coronary microvascular function (e.g., reduced dilation and coronary flow reserve) predicts cardiac mortality in obesity, yet underlying mechanisms and potential therapeutic strategies remain poorly understood. Mineralocorticoid receptor (MR) antagonism improves coronary microvascular function in obese humans and animals. Whether MR blockade improves in vivo regulation of coronary flow, a process involving voltage-dependent K+ (Kv) channel activation, or reduces coronary structural remodeling in obesity is unclear. Thus, the goals of this investigation were to determine the effects of obesity on coronary responsiveness to reductions in arterial PO2 and potential involvement of Kv channels and whether the benefit of MR blockade involves improved coronary Kv function or altered passive structural properties of the coronary microcirculation. Hypoxemia increased coronary blood flow similarly in lean and obese swine; however, baseline coronary vascular resistance was significantly higher in obese swine. Inhibition of Kv channels reduced coronary blood flow and augmented coronary resistance under baseline conditions in lean but not obese swine and had no impact on hypoxemic coronary vasodilation. Chronic MR inhibition in obese swine normalized baseline coronary resistance, did not influence hypoxemic coronary vasodilation, and did not restore coronary Kv function (assessed in vivo, ex vivo, and via patch clamping). Lastly, MR blockade prevented obesity-associated coronary arteriolar stiffening independent of cardiac capillary density and changes in cardiac function. These data indicate that chronic MR inhibition prevents increased coronary resistance in obesity independent of Kv channel function and is associated with mitigation of obesity-mediated coronary arteriolar stiffening.
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26
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Abstract
Hypertension and hypotension are strictly related phenomena, that frequently coexist within the spectrum of cardiovascular autonomic dysfunction, especially at advanced age. Indeed, antihypertensive treatment may predispose to orthostatic and post-prandial hypotension, while intensive blood pressure lowering may be responsible for systemic hypotension. Over recent years, systemic and orthostatic hypotension have emerged as important although often neglected risk factors for adverse outcomes, paralleling the widely recognized arterial hypertension. Both hypertension and hypotension are associated with detrimental effects on target organs and survival, thus significantly impacting patients' prognosis, functional autonomy and quality of life. Balancing low and high blood pressure requires accurate diagnostic assessment of blood pressure values and patients' hypotensive susceptibility, which allow for the development of customized treatment strategies based on individual hypo/hypertensive risk profile. The present review illustrates the complex interrelationship between hypotension and hypertension and discusses the relevant prognostic role of these conditions. Additionally, it provides an overview on hypotension detection and treatment in patients with hypertension, focusing on customized diagnostic and therapeutic strategies.
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Affiliation(s)
- Giulia Rivasi
- Division of Geriatric and Intensive Care Medicine, Careggi Hospital and University of Florence, Florence, Italy -
| | - Artur Fedorowski
- Department of Clinical Sciences, Lund University, Malmö, Sweden.,Department of Cardiology, Skåne University Hospital, Malmö, Sweden
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27
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Peters EL, Bogaard HJ, Vonk Noordegraaf A, de Man FS. Neurohormonal modulation in pulmonary arterial hypertension. Eur Respir J 2021; 58:13993003.04633-2020. [PMID: 33766951 PMCID: PMC8551560 DOI: 10.1183/13993003.04633-2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Accepted: 03/13/2021] [Indexed: 12/15/2022]
Abstract
Pulmonary hypertension is a fatal condition of elevated pulmonary pressures, complicated by right heart failure. Pulmonary hypertension appears in various forms; one of those is pulmonary arterial hypertension (PAH) and is particularly characterised by progressive remodelling and obstruction of the smaller pulmonary vessels. Neurohormonal imbalance in PAH patients is associated with worse prognosis and survival. In this back-to-basics article on neurohormonal modulation in PAH, we provide an overview of the pharmacological and nonpharmacological strategies that have been tested pre-clinically and clinically. The benefit of neurohormonal modulation strategies in PAH patients has been limited by lack of insight into how the neurohormonal system is changed throughout the disease and difficulties in translation from animal models to human trials. We propose that longitudinal and individual assessments of neurohormonal status are required to improve the timing and specificity of neurohormonal modulation strategies. Ongoing developments in imaging techniques such as positron emission tomography may become helpful to determine neurohormonal status in PAH patients in different disease stages and optimise individual treatment responses.
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Affiliation(s)
- Eva L Peters
- Dept of Pulmonology, Amsterdam UMC, Amsterdam, The Netherlands.,Dept of Physiology, Amsterdam UMC, Amsterdam, The Netherlands
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28
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Wengert ER, Wenker IC, Wagner EL, Wagley PK, Gaykema RP, Shin JB, Patel MK. Adrenergic Mechanisms of Audiogenic Seizure-Induced Death in a Mouse Model of SCN8A Encephalopathy. Front Neurosci 2021; 15:581048. [PMID: 33762902 PMCID: PMC7982890 DOI: 10.3389/fnins.2021.581048] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 02/10/2021] [Indexed: 12/14/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death amongst patients whose seizures are not adequately controlled by current therapies. Patients with SCN8A encephalopathy have an elevated risk for SUDEP. While transgenic mouse models have provided insight into the molecular mechanisms of SCN8A encephalopathy etiology, our understanding of seizure-induced death has been hampered by the inability to reliably trigger both seizures and seizure-induced death in these mice. Here, we demonstrate that mice harboring an Scn8a allele with the patient-derived mutation N1768D (D/+) are susceptible to audiogenic seizures and seizure-induced death. In adult D/+ mice, audiogenic seizures are non-fatal and have nearly identical behavioral, electrographical, and cardiorespiratory characteristics as spontaneous seizures. In contrast, at postnatal days 20–21, D/+ mice exhibit the same seizure behavior, but have a significantly higher incidence of seizure-induced death following an audiogenic seizure. Seizure-induced death was prevented by either stimulating breathing via mechanical ventilation or by acute activation of adrenergic receptors. Conversely, in adult D/+ mice inhibition of adrenergic receptors converted normally non-fatal audiogenic seizures into fatal seizures. Taken together, our studies show that in our novel audiogenic seizure-induced death model adrenergic receptor activation is necessary and sufficient for recovery of breathing and prevention of seizure-induced death.
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Affiliation(s)
- Eric R Wengert
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, United States.,Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, VA, United States
| | - Ian C Wenker
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, United States
| | - Elizabeth L Wagner
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States.,Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Pravin K Wagley
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, United States
| | - Ronald P Gaykema
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, United States
| | - Jung-Bum Shin
- Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, VA, United States.,Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Manoj K Patel
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, United States.,Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, VA, United States
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29
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Chong T, Nguyen M. Renal Denervation: A Revival or The Same Old Story. Heart Lung Circ 2021; 30:843-847. [PMID: 33612429 DOI: 10.1016/j.hlc.2020.12.020] [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: 07/21/2020] [Revised: 11/10/2020] [Accepted: 12/30/2020] [Indexed: 10/22/2022]
Abstract
Despite well-established pharmacological treatment, hypertension has remained a large contributor to noncommunicable deaths. Given the well-known association of hypertension with adverse cardiovascular disease the importance of blood pressure control has never been more crucial. Traditionally, pharmacological management has been the mainstay of care, however, with a growing burden of disease alternative and innovative approaches are now being considered. Minimally invasive catheter-based ablation systems, targeting renal sympathetic nerves, has been proposed as a more permanent way to control blood pressure. However, the clinical data supporting renal denervation has had many rises and falls throughout the years. With the promising results of the recent second-generation clinical trials there has been a renewed area of interest for renal denervation in the treatment of hypertension.
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Affiliation(s)
- Travis Chong
- Department of Cardiology, Fiona Stanley Hospital, Perth, WA, Australia.
| | - Michael Nguyen
- Department of Population Health, University of Western Australia, Perth, WA, Australia
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30
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Convertino VA, Koons NJ, Suresh MR. Physiology of Human Hemorrhage and Compensation. Compr Physiol 2021; 11:1531-1574. [PMID: 33577122 DOI: 10.1002/cphy.c200016] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.
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Affiliation(s)
- Victor A Convertino
- Battlefield Healthy & Trauma Center for Human Integrative Physiology, United States Army Institute of Surgical Research, JBSA San Antonio, Texas, USA
| | - Natalie J Koons
- Battlefield Healthy & Trauma Center for Human Integrative Physiology, United States Army Institute of Surgical Research, JBSA San Antonio, Texas, USA
| | - Mithun R Suresh
- Battlefield Healthy & Trauma Center for Human Integrative Physiology, United States Army Institute of Surgical Research, JBSA San Antonio, Texas, USA
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31
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Pachen M, Abukar Y, Shanks J, Lever N, Ramchandra R. Activation of the carotid body increases directly recorded cardiac sympathetic nerve activity and coronary blood flow in conscious sheep. Am J Physiol Regul Integr Comp Physiol 2020; 320:R203-R212. [PMID: 33206558 DOI: 10.1152/ajpregu.00246.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Activation of the carotid body (CB) using intracarotid potassium cyanide (KCN) injection increases coronary blood flow (CoBF). This increase in CoBF is considered to be mediated by co-activation of both the sympathetic and parasympathetic nerves to the heart. However, whether cardiac sympathetic nerve activity (cardiac SNA) actually increases during CB activation has not been determined previously. We hypothesized that activation of the CB would increase directly recorded cardiac SNA, which would cause coronary vasodilatation. Experiments were conducted in conscious sheep implanted with electrodes to record cardiac SNA and diaphragmatic electromyography (dEMG), flow probes to record CoBF and cardiac output, and a catheter to record arterial pressure. Intracarotid KCN injection was used to activate the CB. To eliminate the contribution of metabolic demand on coronary flow, the heart was paced at a constant rate during CB chemoreflex stimulation. Intracarotid KCN injection resulted in a significant increase in directly recorded cardiac SNA frequency (from 24 ± 2 to 40 ± 4 bursts/min; P < 0.05) as well as a dose-dependent increase in mean arterial pressure (79 ± 15 to 88 ± 14 mmHg; P < 0.01) and CoBF (75 ± 37 vs. 86 ± 42 mL/min; P < 0.05). The increase in CoBF and coronary vascular conductance to intracarotid KCN injection was abolished after propranolol infusion, suggesting that the increased cardiac SNA mediates coronary vasodilatation. The pressor response to activation of the CB was abolished by pretreatment with intravenous atropine, but there was no change in the coronary flow response. Our results indicate that CB activation increases directly recorded cardiac SNA, which mediates vasodilatation of the coronary vasculature.
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Affiliation(s)
- Mridula Pachen
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Yonis Abukar
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Julia Shanks
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Nigel Lever
- Department of Medicine, University of Auckland and Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | - Rohit Ramchandra
- Department of Physiology, University of Auckland, Auckland, New Zealand
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32
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Prasad B, Morgan BJ, Gupta A, Pegelow DF, Teodorescu M, Dopp JM, Dempsey JA. The need for specificity in quantifying neurocirculatory vs. respiratory effects of eucapnic hypoxia and transient hyperoxia. J Physiol 2020; 598:4803-4819. [PMID: 32770545 DOI: 10.1113/jp280515] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 08/04/2020] [Indexed: 12/24/2022] Open
Abstract
KEY POINTS The carotid chemoreceptor mediates the ventilatory and muscle sympathetic nerve activity (MSNA) responses to hypoxia and contributes to tonic sympathetic and respiratory drives. It is often presumed that both excitatory and inhibitory tests of chemoreflex function show congruence in the end-organ responses. Ventilatory and neurocirculatory (MSNA, blood pressure and heart rate) responses to chemoreflex inhibition elicited by transient hyperoxia and to chemoreflex excitation produced by steady-state eucapnic hypoxia were measured in a cohort of 82 middle-aged individuals. Ventilatory and MSNA responsiveness to hyperoxia and hypoxia were not significantly correlated within individuals. It was concluded that ventilatory responses to hypoxia and hyperoxia do not predict MSNA responses and it is recommended that tests using the specific outcome of interest, i.e. MSNA or ventilation, are required. Transient hyperoxia is recommended as a sensitive and reliable means of quantifying tonic chemoreceptor-driven levels of sympathetic nervous system activity and respiratory drive. ABSTRACT Hypersensitivity of the carotid chemoreceptor leading to sympathetic nervous system activation and ventilatory instability has been implicated in the pathogenesis and consequences of several common clinical conditions. A variety of treatment approaches aimed at lessening chemoreceptor-driven sympathetic overactivity are now under investigation; thus, the ability to quantify this outcome variable with specificity and precision is crucial. Accordingly, we measured ventilatory and neurocirculatory responses to chemoreflex inhibition elicited by transient hyperoxia and chemoreflex excitation produced by exposure to graded, steady-state eucapnic hypoxia in middle-aged men and women (n = 82) with continuous positive airway pressure-treated obstructive sleep apnoea. Progressive, eucapnic hypoxia produced robust and highly variable increases in ventilation (+83 ± 59%) and muscle sympathetic nerve activity (MSNA) burst frequency (+55 ± 31%), whereas transient hyperoxia caused marked reductions in these variables (-35 ± 14% and -42 ± 16%, respectively). Coefficients of variation for ventilatory and MSNA burst frequency responses, indicating test-retest reproducibility, were respectively 9% and 24% for hyperoxia and 35% and 28% for hypoxia. Based on statistical measures of rank correlation or even comparisons across quartiles of corresponding ventilatory and MSNA responses, we found that the magnitudes of ventilatory inhibition with hyperoxia or excitation with eucapnic hypoxia were not correlated with corresponding MSNA responses within individuals. We conclude that, in conscious, behaving humans, ventilatory sensitivities to progressive, steady-state, eucapnic hypoxia and transient hyperoxia do not predict MSNA responsiveness. Our findings also support the use of transient hyperoxia as a reliable, sensitive, measure of the carotid chemoreceptor contribution to tonic sympathetic nervous system activity and respiratory drive.
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Affiliation(s)
- Bharati Prasad
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Barbara J Morgan
- John Rankin Laboratory of Pulmonary Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.,Department of Orthopedics and Rehabilitation, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Ahana Gupta
- GPPA Medical Scholars Program, University of Illinois at Chicago, Chicago, IL, USA
| | - David F Pegelow
- Department of Pediatrics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Mihaela Teodorescu
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - John M Dopp
- Pharmacy Practice Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Jerome A Dempsey
- John Rankin Laboratory of Pulmonary Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.,Department of Population Health Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, WI, USA
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33
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Brognara F, Felippe ISA, Salgado HC, Paton JFR. Autonomic innervation of the carotid body as a determinant of its sensitivity: implications for cardiovascular physiology and pathology. Cardiovasc Res 2020; 117:1015-1032. [PMID: 32832979 DOI: 10.1093/cvr/cvaa250] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 07/01/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
The motivation for this review comes from the emerging complexity of the autonomic innervation of the carotid body (CB) and its putative role in regulating chemoreceptor sensitivity. With the carotid bodies as a potential therapeutic target for numerous cardiorespiratory and metabolic diseases, an understanding of the neural control of its circulation is most relevant. Since nerve fibres track blood vessels and receive autonomic innervation, we initiate our review by describing the origins of arterial feed to the CB and its unique vascular architecture and blood flow. Arterial feed(s) vary amongst species and, unequivocally, the arterial blood supply is relatively high to this organ. The vasculature appears to form separate circuits inside the CB with one having arterial venous anastomoses. Both sympathetic and parasympathetic nerves are present with postganglionic neurons located within the CB or close to it in the form of paraganglia. Their role in arterial vascular resistance control is described as is how CB blood flow relates to carotid sinus afferent activity. We discuss non-vascular targets of autonomic nerves, their possible role in controlling glomus cell activity, and how certain transmitters may relate to function. We propose that the autonomic nerves sub-serving the CB provide a rapid mechanism to tune the gain of peripheral chemoreflex sensitivity based on alterations in blood flow and oxygen delivery, and might provide future therapeutic targets. However, there remain a number of unknowns regarding these mechanisms that require further research that is discussed.
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Affiliation(s)
- Fernanda Brognara
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand.,Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Igor S A Felippe
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
| | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Grafton Auckland 1023, New Zealand
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Beltrán AR, Arce-Álvarez A, Ramirez-Campillo R, Vásquez-Muñoz M, von Igel M, Ramírez MA, Del Rio R, Andrade DC. Baroreflex Modulation During Acute High-Altitude Exposure in Rats. Front Physiol 2020; 11:1049. [PMID: 32973562 PMCID: PMC7472463 DOI: 10.3389/fphys.2020.01049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/30/2020] [Indexed: 12/25/2022] Open
Abstract
Baroreflex (BR) control is critically dependent of sympathetic and parasympathetic modulation. It has been documented that during acute hypobaric hypoxia there is a BR control impairment, however, the effect of a natural hypoxic environment on BR function is limited and controversial. Therefore, the aim of this study was to determine the effect of acute High-Altitude exposure on sympathetic/parasympathetic modulation of BR control in normal rats. Male Sprague Dawley rats were randomly allocated into Sea-Level (n = 7) and High-Altitude (n = 5) (3,270 m above sea level) groups. The BR control was studied using phenylephrine (Phe) and sodium nitroprusside (SNP) through sigmoidal analysis. The autonomic control of the heart was estimated using heart rate variability (HRV) analysis in frequency domain. Additionally, to determine the maximum sympathetic and parasympathetic activation of BR, spectral non-stationary method analysis, during Phe (0.05 μg/mL) and SNP administration (0.10 μg/mL) were used. Compared to Sea-Level condition, the High-Altitude group displayed parasympathetic withdrawal (high frequency, 0.6-2.4 Hz) and sympathoexcitation (low frequency, 0.04-0.6 Hz). Regarding to BR modulation, rats showed a significant decrease (p < 0.05) of curvature and parasympathetic bradycardic responses to Phe, without significant differences in sympathetic tachycardic responses to SNP after High-Altitude exposure. In addition, the non-stationary analysis of HRV showed a reduction of parasympathetic activation (Phe) in the High-Altitude group. Our results suggest that acute exposure to High-Altitude produces an autonomic and BR control impairment, characterized by parasympathetic withdrawal after 24 h of high-altitude exposure.
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Affiliation(s)
- Ana Rosa Beltrán
- Departamento de Educación, Facultad de Educación, Universidad de Antofagasta, Antofagasta, Chile
- Laboratorio de Fisiología Celular, Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Alexis Arce-Álvarez
- Escuela de Kinesiología, Facultad de Salud, Universidad Católica Silva Henríquez, Santiago, Chile
| | - Rodrigo Ramirez-Campillo
- Laboratory of Human Performance, Quality of Life and Wellness Research Group, Department of Physical Activity Sciences, Universidad de Los Lagos, Osorno, Chile
- Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Manuel Vásquez-Muñoz
- Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Magdalena von Igel
- Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Marco A. Ramírez
- Laboratorio de Fisiología Celular, Departamento Biomédico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
| | - David C. Andrade
- Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
- Pedagogía en Educación Física, Deportes y Recreación, Universidad Mayor, Santiago, Chile
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Ferreira CB, Schoorlemmer GH, Rocha AA, Cravo SL. Increased sympathetic responses induced by chronic obstructive sleep apnea are caused by sleep fragmentation. J Appl Physiol (1985) 2020; 129:163-172. [PMID: 32552428 DOI: 10.1152/japplphysiol.00811.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Obstructive sleep apnea (OSA) is often associated with sympathetic overactivity and hypertension. These associations are mainly attributed to hypoxia acting on arterial chemoreceptors. However, the contribution of arousal from sleep is unclear. We measured the effect of OSA and sleep fragmentation on cardiovascular and sympathetic function and gene expression in the brain in rats. Male Wistar rats were fitted with a tracheal balloon and EEG and electromyogram electrodes and assigned to control (n = 6), OSA (n = 9), or arousal (n = 8) treatments. The OSA group was subjected to obstructive apnea, each time the rat entered sleep, for 8 h/day for 15 days. The arousal group was similarly exposed to vibration, which was produced with a miniature vibration motor mounted on the rat's head. Vibration intensity slowly increased until the rat awoke. One day after the last apnea or arousal, rats were anesthetized and arterial blood pressure and splanchnic sympathetic nerve activity (SSNA) were recorded. Baseline mean and diastolic pressure were increased after OSA. Resting SSNA was similar in the three groups, but both OSA and sleep fragmentation increased sympathetic activation in response to airway obstruction and chemoreflex activation by cyanide. OSA increased superoxide dismutases 1 and 2 in the brainstem, whereas sleep fragmentation did not. Our results suggest that sympathetic overactivity to chemoreceptor stimulation was a consequence of arousal from sleep. Our study suggests that sleep disruption may have an important role in the development of apnea-related sympathetic activation.NEW & NOTEWORTHY Obstructive sleep apnea causes a hyperactive chemoreflex, with increased sympathetic activation. However, it is not clear whether this pathophysiologic mechanism is due to repeated hypoxia or to sleep disruption. The present study suggests that sleep fragmentation contributes importantly to increased sympathetic activation after chemoreceptor stimulation. This suggests that sleep fragmentation has an important role in the sympathetic activation seen in sleep apnea patients.
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Affiliation(s)
- Caroline B Ferreira
- Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Guus H Schoorlemmer
- Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Antonio A Rocha
- Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Sergio L Cravo
- Departamento de Fisiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Collins SÉ, Phillips DB, McMurtry MS, Bryan TL, Paterson DI, Wong E, Ezekowitz JA, Forhan MA, Stickland MK. The Effect of Carotid Chemoreceptor Inhibition on Exercise Tolerance in Chronic Heart Failure. Front Physiol 2020; 11:195. [PMID: 32226392 PMCID: PMC7080702 DOI: 10.3389/fphys.2020.00195] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/20/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose Chronic heart failure (CHF) is characterized by heightened sympathetic nervous activity, carotid chemoreceptor (CC) sensitivity, marked exercise intolerance and an exaggerated ventilatory response to exercise. The purpose of this study was to determine the effect of CC inhibition on exercise cardiovascular and ventilatory function, and exercise tolerance in health and CHF. Methods Twelve clinically stable, optimally treated patients with CHF (mean ejection fraction: 43 ± 2.5%) and 12 age- and sex-matched healthy controls were recruited. Participants completed two time-to-symptom-limitation (TLIM) constant load cycling exercise tests at 75% peak power output with either intravenous saline or low-dose dopamine (2 μg⋅kg–1⋅min–1; order randomized). Ventilation was measured using expired gas data and operating lung volume data were determined during exercise by inspiratory capacity maneuvers. Cardiac output was estimated using impedance cardiography, and vascular conductance was calculated as cardiac output/mean arterial pressure. Results There was no change in TLIM in either group with dopamine (CHF: saline 13.1 ± 2.4 vs. dopamine 13.5 ± 1.6 min, p = 0.78; Control: saline 10.3 ± 1.2 vs. dopamine 11.5 ± 1.3 min, p = 0.16). In CHF patients, dopamine increased cardiac output (p = 0.03), vascular conductance (p = 0.01) and oxygen delivery (p = 0.04) at TLIM, while ventilatory parameters were unaffected (p = 0.76). In controls, dopamine improved vascular conductance at TLIM (p = 0.03), but no other effects were observed. Conclusion Our findings suggest that the CC contributes to cardiovascular regulation during full-body exercise in patients with CHF, however, CC inhibition does not improve exercise tolerance.
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Affiliation(s)
- Sophie É Collins
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Devin B Phillips
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
| | - M Sean McMurtry
- Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Tracey L Bryan
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - D Ian Paterson
- Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Eric Wong
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Justin A Ezekowitz
- Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Mary A Forhan
- Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
| | - Michael K Stickland
- Division of Pulmonary Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.,G.F. MacDonald Centre for Lung Health, Covenant Health, Edmonton, AB, Canada
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Gaudio E, Laubscher LL, Pfitzer S, Raath JP, Hoffman LC, De Benedictis GM. Immobilization quality and cardiopulmonary effects of etorphine alone compared with etorphine-azaperone in blesbok (Damaliscus pygargus phillipsi). Vet Anaesth Analg 2020; 47:528-536. [PMID: 32507718 DOI: 10.1016/j.vaa.2019.10.012] [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: 04/16/2019] [Revised: 09/04/2019] [Accepted: 10/07/2019] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To evaluate the immobilization quality and cardiopulmonary effects of etorphine alone compared with etorphine-azaperone in blesbok (Damaliscus pygargus phillipsi). STUDY DESIGN Blinded, randomized, crossover design. ANIMALS A total of 12 boma-habituated female blesbok weighing [mean ± standard deviation (SD)] 57.5 ± 2.5 kg. METHODS Each animal was administered etorphine (0.09 mg kg-1) or etorphine-azaperone (0.09 mg kg-1; 0.35 mg kg-1) intramuscularly with 1-week intertreatment washout period. Time to first sign of altered state of consciousness and immobilization time were recorded. Physiological variables were recorded, arterial blood samples were taken during a 40-minute immobilization period, and naltrexone (mean ± SD: 1.83 ± 0.06 mg kg-1) was intravenously administered. Recovery times were documented, and induction, immobilization and recovery were subjectively scored. Statistical analyses were performed; p < 0.05 was significant. RESULTS No difference was observed in time to first sign, immobilization time and recovery times between treatments. Time to head up was longer with etorphine-azaperone (0.5 ± 0.2 versus 0.4 ± 0.2 minutes; p = 0.015). Etorphine caused higher arterial blood pressures (mean: 131 ± 17 versus 110 ± 11 mmHg, p < 0.0001), pH, rectal temperature and arterial oxygen partial pressure (59.2 ± 7.7 versus 42.2 ± 9.8 mmHg), but lower heart (p = 0.002) and respiratory rates (p = 0.01). Etorphine-azaperone combination led to greater impairment of ventilatory function, with higher end-tidal carbon dioxide (p < 0.0001) and arterial partial pressure of carbon dioxide (58.0 ± 4.5 versus 48.1 ± 5.1 mmHg). Immobilization quality was greater with etorphine-azaperone than with etorphine alone (median scores: 4 versus 3; p < 0.0001). CONCLUSIONS AND CLINICAL RELEVANCE Both treatments provided satisfactory immobilization of blesbok; however, in addition to a deeper level of immobilization, etorphine-azaperone caused greater ventilatory impairment. Oxygen supplementation is recommended with both treatments.
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Affiliation(s)
- Eugenio Gaudio
- Department of Animal Medicine Production and Health, University of Padova, Padova, Italy; Department of Animal Sciences, Stellenbosch University, Stellenbosch, South Africa.
| | - Liesel L Laubscher
- Department of Animal Sciences, Stellenbosch University, Stellenbosch, South Africa; Wildlife Pharmaceuticals (Pty) Ltd., White River, South Africa
| | - Silke Pfitzer
- School of Veterinary and Life Sciences, Murdoch University, Perth, Australia
| | - Jacobus P Raath
- Wildlife Pharmaceuticals (Pty) Ltd., White River, South Africa; Wildlifevets.com, Ngongoni Game Lodge, Karino, South Africa
| | - Louw C Hoffman
- Department of Animal Sciences, Stellenbosch University, Stellenbosch, South Africa; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Australia
| | - Giulia M De Benedictis
- Department of Animal Medicine Production and Health, University of Padova, Padova, Italy
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Long-term stimulation of cardiac vagal preganglionic neurons reduces blood pressure in the spontaneously hypertensive rat. J Hypertens 2019; 36:2444-2452. [PMID: 30045362 DOI: 10.1097/hjh.0000000000001871] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Arterial hypertension is associated with autonomic nervous system dysfunction. Different interventional strategies have been implemented in recent years for the reduction of sympathetic activity in patients with hypertension. However, the therapeutic benefit of increasing vagal tone in hypertensive patients remains largely unexplored. OBJECTIVE Here, we describe the effects of long-term activation of vagal neural pathways on arterial pressure, heart rate arterial pressure variability and spontaneous baroreflex sensitivity in spontaneously hypertensive rats (SHR) and normotensive Wistar rats. METHODS Brainstem vagal preganglionic neurons residing in the dorsal vagal motor nucleus (DVMN) were targeted with a lentiviral vector to induce the expression of an artificial G(s) protein-coupled receptor termed designer receptors exclusively activated by designer drugs (DREADD-Gs). The transduced neurons were activated daily by systemic administration of otherwise inert ligand clozapine-n-oxide. Arterial pressure measurements were recorded in conscious freely moving animals after 21 consecutive days of DVMN stimulation. RESULTS Resting arterial pressure was significantly lower in SHRs expressing DREADD-Gs in the DVMN, compared with control SHRs expressing enhanced green fluorescent protein. No changes in arterial pressure were detected in Wistar rats expressing DREADD-Gs compared with rats expressing enhanced green fluorescent protein in the DVMN. Pharmacogenetic activation of DREADD-Gs-expressing DVMN neurons in SHRs was accompanied with increased baroreflex sensitivity and a paradoxical decrease in cardio-vagal components of heart rate and systolic arterial pressure variability in SHRs. CONCLUSION These results suggest that long-term activation of vagal parasympathetic pathways is beneficial in restoring autonomic balance in an animal model of neurogenic hypertension and might be an effective therapeutic approach for the management of hypertension.
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Xie L, Di X, Zhao F, Yao J, Liu Z, Li C, Liu B, Wang X, Zhang J. Increased Respiratory Modulation of Blood Pressure in Hypertensive Patients. Front Physiol 2019; 10:1111. [PMID: 31507459 PMCID: PMC6718561 DOI: 10.3389/fphys.2019.01111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/12/2019] [Indexed: 11/20/2022] Open
Abstract
Objective Although the important role of respiratory modulation of the cardiovascular system in the development of hypertension has been demonstrated in animal studies, little research has assessed this modulation in essential hypertensive patients. We aimed to explore whether respiratory-related variations in cardiovascular variables are changed in hypertensive patients and their potential relationships with the respiratory pattern. Methods Respiration, ECG, and beat-to-beat blood pressure (BP) were simultaneously measured in 46 participants (24 hypertensive patients and 22 normotensive participants) during rest and a mental arithmetic task (MAT). Respiratory-triggered averaging and orthogonal subspace projection methods were used to assess the respiratory modulations of BP and heart rate (HR). Respiratory parameters including inspiratory time, expiratory time, respiratory rate and their variabilities were also characterized. Results The inspiratory time, expiratory time, respiratory rate and their variabilities were not different between hypertensive and normotensives. Additionally, the modulation of HR by respiration was also similar between the two groups. Hypertensive patients exhibited an amplified respiratory modulation of systolic BP (SBP), as assessed from the amplitude of respiratory-related changes and the percentage of the power of respiratory-related variation, and also reflected from the temporal pattern of respiratory modulation of SBP. The exaggerated respiratory-related variation of SBP in hypertensive patients accounted for ≈23% of the total power of SBP, producing an absolute change of ≈4.5 mmHg in SBP. MAT was characterized by decreased inspiratory time and increased variabilities of expiratory time and respiratory rate with no changes in the amplitude of respiratory modulations. Conclusion Hypertensive patients had excessive respiratory modulation of SBP, despite having similar respiratory pattern with normotensives. These findings highlight the importance of respiratory influence in BP variation and suggest that respiratory modulation of SBP may have prognostic information for cardiovascular events in hypertensive patients.
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Affiliation(s)
- Lin Xie
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Xiaohui Di
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Fadong Zhao
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Jie Yao
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Zhiheng Liu
- Department of Cardiology, No. 451 Hospital of Chinese People's Liberation Army, Xi'an, China
| | - Chaomin Li
- Department of Cardiology, No. 451 Hospital of Chinese People's Liberation Army, Xi'an, China
| | - Binbin Liu
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Xiaoni Wang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
| | - Jianbao Zhang
- Key Laboratory of Biomedical Information Engineering of Education Ministry, Xi'an Jiaotong University, Xi'an, China
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Integration of hindbrain and carotid body mechanisms that control the autonomic response to cardiorespiratory and glucoprivic insults. Respir Physiol Neurobiol 2019; 265:83-91. [DOI: 10.1016/j.resp.2018.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 08/01/2018] [Accepted: 08/29/2018] [Indexed: 01/08/2023]
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Shinoda M, Saku K, Oga Y, Tohyama T, Nishikawa T, Abe K, Yoshida K, Kuwabara Y, Fujii K, Ishikawa T, Kishi T, Sunagawa K, Tsutsui H. Suppressed baroreflex peripheral arc overwhelms augmented neural arc and incapacitates baroreflex function in rats with pulmonary arterial hypertension. Exp Physiol 2019; 104:1164-1178. [PMID: 31140668 DOI: 10.1113/ep087253] [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: 07/21/2018] [Accepted: 05/28/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The impact of pulmonary arterial hypertension on open-loop baroreflex function, which determines how powerfully and rapidly the baroreflex operates to regulate arterial pressure, remains poorly understood. What is the main finding and its importance? The gain of the baroreflex total arc, indicating the baroreflex pressure-stabilizing function, is markedly attenuated in rats with monocrotaline-induced pulmonary arterial hypertension. This is caused by a rightward shift of the baroreflex neural arc and a downward shift of the peripheral arc. These findings contribute greatly to our understanding of arterial pressure regulation by the sympathetic nervous system in pulmonary arterial hypertension. ABSTRACT Sympathoexcitation has been documented in patients with established pulmonary arterial hypertension (PAH). Although the arterial baroreflex is the main negative feedback regulator of sympathetic nerve activity (SNA), the way in which PAH impacts baroreflex function remains poorly understood. In this study, we conducted baroreflex open-loop analysis in a rat model of PAH. Sprague-Dawley rats were injected with monocrotaline (MCT) s.c. to induce PAH (60 mg kg-1 ; n = 11) or saline as a control group (CTL; n = 8). At 3.5 weeks after MCT injection, bilateral carotid sinuses were isolated, and intrasinus pressure (CSP) was controlled while SNA at the coeliac ganglia and arterial pressure (AP) were recorded. To examine the static baroreflex function, CSP was increased stepwise while steady-state AP (total arc) and SNA (neural arc) responses to CSP and the AP response to SNA (peripheral arc) were measured. Monocrotaline significantly decreased the static gain of the baroreflex total arc at the operating AP compared with CTL (-0.80 ± 0.31 versus -0.22 ± 0.22, P < 0.05). Given that MCT markedly increased plasma noradrenaline, an index of SNA, by approximately 3.6-fold compared with CTL, calibrating SNA by plasma noradrenaline revealed that MCT shifted the neural arc to a higher SNA level and shifted the peripheral arc downwards. Monocrotaline also decreased the dynamic gain of the baroreflex total arc (-0.79 ± 0.16 versus -0.35 ± 0.17, P < 0.05), while the corner frequencies that reflect the speed of the baroreflex remained unchanged (0.06 ± 0.02 versus 0.08 ± 0.02 Hz, n.s.). In rats with MCT-induced PAH, the suppressed baroreflex peripheral arc overwhelms the augmented neural arc and, in turn, attenuates the gain of the total arc, which determines the pressure-stabilizing capacity of the baroreflex.
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Affiliation(s)
- Masako Shinoda
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Keita Saku
- Department of Advanced Risk Stratification for Cardiovascular Diseases, Center for Disruptive Cardiovascular Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Yasuhiro Oga
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Takeshi Tohyama
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Takuya Nishikawa
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Kohtaro Abe
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Keimei Yoshida
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Yukimitsu Kuwabara
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Kana Fujii
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Tomohito Ishikawa
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Takuya Kishi
- Department of Advanced Risk Stratification for Cardiovascular Diseases, Center for Disruptive Cardiovascular Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Kenji Sunagawa
- Department of Therapeutic Regulation of Cardiovascular Homeostasis, Center for Disruptive Cardiovascular Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Hiroyuki Tsutsui
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
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Abstract
PURPOSE OF REVIEW An abnormal heightened carotid body (CB) chemoreflex, which produces autonomic dysfunction and sympathetic overactivation, is the common hallmark of obstructive sleep apnea (OSA), resistant hypertension, systolic heart failure (HF), and cardiometabolic diseases. Accordingly, it has been proposed that the elimination of the CB chemosensory input to the brainstem may reduce the autonomic and cardiorespiratory alterations in sympathetic-associated diseases in humans. RECENT FINDINGS A growing body of evidence obtained in preclinical animal models support that an enhanced CB discharge produces sympathetic hyperactivity, baroreflex sensitivity and heart rate variability impairment, breathing instability, hypertension, and insulin resistance. The elimination CB chemosensory input reduces the sympathetic hyperactivity, the elevated arterial blood pressure in OSA and hypertensive models, abolishes breathing instability and improves animal survival in HF models, and restores insulin tolerance in metabolic models. These results highlight the role played by the enhanced CB drive in the progression of sympathetic-related diseases and support the proposal that the surgical ablation of the CB is useful to restore the autonomic balance and normal cardiorespiratory function in humans. Accordingly, the CB ablation has been used in pilot human studies as a therapeutic treatment for resistant hypertension and HF-induced sympathetic hyperactivity. In this review, I will discuss the supporting evidence for a crucial contribution of the CB in the central autonomic dysfunction and the pros and cons of the CB ablation as a therapy to revert autonomic overactivation. The CB ablation could be a useful method to reverse the enhanced chemoreflex in HF and severe hypertension, but caution is required before extensive use of bilateral CB ablation, which abolished ventilatory responses to hypoxia and may impair baroreceptor function.
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Sharma RK, Oliveira AC, Kim S, Rigatto K, Zubcevic J, Rathinasabapathy A, Kumar A, Lebowitz JJ, Khoshbouei H, Lobaton G, Aquino V, Richards EM, Katovich MJ, Shenoy V, Raizada MK. Involvement of Neuroinflammation in the Pathogenesis of Monocrotaline-Induced Pulmonary Hypertension. Hypertension 2018; 71:1156-1163. [PMID: 29712738 DOI: 10.1161/hypertensionaha.118.10934] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 02/03/2018] [Accepted: 04/04/2018] [Indexed: 12/28/2022]
Abstract
Pulmonary hypertension (PH) is a devastating disease and its successful treatment remains to be accomplished despite recent advances in pharmacotherapy. It has been proposed that PH be considered as a systemic disease, rather than primarily a disease of the pulmonary vasculature. Consequently, an investigation of the intricate interplay between multiple organs such as brain, vasculature, and lung in PH could lead to the identification of new targets for its therapy. However, little is known about this interplay. This study was undertaken to examine the concept that altered autonomic-pulmonary communication is important in PH pathophysiology. Therefore, we hypothesize that activation of microglial cells in the paraventricular nucleus of hypothalamus and neuroinflammation is associated with increased sympathetic drive and pulmonary pathophysiology contributing to PH. We utilized the monocrotaline rat model for PH and intracerebroventricular administration of minocycline for inhibition of microglial cells activation to investigate this hypothesis. Hemodynamic, echocardiographic, histological, immunohistochemical, and confocal microscopic techniques assessed cardiac and pulmonary function and microglial cells. Monocrotaline treatment caused cardiac and pulmonary pathophysiology associated with PH. There were also increased activated microglial cells and mRNA for proinflammatory cytokines (IL [interleukin]-1β, IL-6, and TNF [tumor necrosis factor]-α) in the paraventricular nucleus. Furthermore, increased sympathetic drive and plasma norepinephrine were observed in rats with PH. Intracerebroventricular infusion of minocycline inhibited all these parameters and significantly attenuated PH. These observations implicate a dysfunctional autonomic-lung communication in the development and progression of PH providing new therapeutic targets, such as neuroinflammation, for PH therapy.
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Affiliation(s)
- Ravindra K Sharma
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Aline C Oliveira
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Seungbum Kim
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Katya Rigatto
- College of Medicine, University of Florida, Gainesville; Department of Basic Health Sciences, Federal University of Health Sciences of Porto Alegre, Brazil (K.R.)
| | - Jasenka Zubcevic
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville (J.Z.)
| | - Anandharajan Rathinasabapathy
- Department of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN (A.R.)
| | - Ashok Kumar
- Department of Medicine, Brown University and VA Medical Center, Providence, RI (A.K.)
| | | | | | - Gilberto Lobaton
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Victor Aquino
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Elaine M Richards
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
| | - Michael J Katovich
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville (M.J.K.)
| | - Vinayak Shenoy
- and Department of Pharmaceutical and Biomedical Sciences, California Health Sciences University, Clovis (V.S.).
| | - Mohan K Raizada
- From the Department of Physiology and Functional Genomics (R.K.S., A.C.O., S.K., G.L., V.A., E.M.R., M.K.R.)
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Coldren KM, Li DP, Kline DD, Hasser EM, Heesch CM. Acute hypoxia activates neuroendocrine, but not presympathetic, neurons in the paraventricular nucleus of the hypothalamus: differential role of nitric oxide. Am J Physiol Regul Integr Comp Physiol 2017; 312:R982-R995. [PMID: 28404583 DOI: 10.1152/ajpregu.00543.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/06/2017] [Accepted: 04/07/2017] [Indexed: 11/22/2022]
Abstract
Hypoxia results in decreased arterial Po2, arterial chemoreflex activation, and compensatory increases in breathing, sympathetic outflow, and neuroendocrine secretions, including increased secretion of AVP, corticotropin-releasing hormone (CRH), adrenocorticotropin hormone (ACTH), and corticosterone. In addition to a brain stem pathway, including the nucleus tractus solitarius (nTS) and the rostral ventrolateral medulla (RVLM), medullary pathways to the paraventricular nucleus of the hypothalamus (PVN) contribute to chemoreflex responses. Experiments evaluated activation of specific cell phenotypes within the PVN following an acute hypoxic stimulus (AH; 2 h, 10% O2) in conscious rats. Retrograde tracers (from spinal cord and RVLM) labeled presympathetic (PreS) neurons, and immunohistochemistry identified AVP- and CRH-immunoreactive (IR) cells. c-Fos-IR was an index of neuronal activation. Hypoxia activated AVP-IR (~6%) and CRH-IR (~15%) cells, but not PreS cells in the PVN, suggesting that sympathoexcitation during moderate AH is mediated mainly by a pathway that does not include PreS neurons in the PVN. Approximately 14 to 17% of all PVN cell phenotypes examined expressed neuronal nitric oxide synthase (nNOS-IR). AH activated only nNOS-negative AVP-IR neurons. In contrast ~23% of activated CRH-IR neurons in the PVN contained nNOS. In the median eminence, CRH-IR terminals were closely opposed to tanycyte processes and end-feet (vimentin-IR) in the external zone, where vascular NO participates in tanycyte retraction to facilitate neuropeptide secretion into the pituitary portal circulation. Results are consistent with an inhibitory role of NO on AVP and PreS neurons in the PVN and an excitatory role of NO on CRH secretion in the PVN and median eminence.
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Affiliation(s)
- K Max Coldren
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - De-Pei Li
- Department of Critical Care, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - David D Kline
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Interdisciplinary Neuroscience Program, University of Missouri, Columbia, Missouri
| | - Eileen M Hasser
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri.,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri; and
| | - Cheryl M Heesch
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri; .,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri.,Interdisciplinary Neuroscience Program, University of Missouri, Columbia, Missouri
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A model-based method to measure baroreflex sensitivity. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:2688-2691. [PMID: 28268875 DOI: 10.1109/embc.2016.7591284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This paper proposes a model-based method to quantitatively measure baroreflex sensitivity in autonomic nervous regulation of cardiovascular system. The method measures the continuous blood pressure and heart rate in orthostatic scenario, models dynamics of the baroreflex firing rate, solves parameters by optimization of measured blood pressure and heart rate variations. With this model, we can get the baroreflx sensitivity (BRS) inner indicators to evaluate the status of the autonomic nervous regulation system. Experimental results have shown the validation of the quantitative measures and the effectiveness of the method.
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CARDIOVASCULAR EFFECTS OF ETORPHINE, AZAPERONE, AND BUTORPHANOL COMBINATIONS IN CHEMICALLY IMMOBILIZED CAPTIVE WHITE RHINOCEROS (CERATOTHERIUM SIMUM). J Zoo Wildl Med 2017; 47:834-843. [PMID: 27691950 DOI: 10.1638/2015-0298.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Chemical capture is an essential tool in the management and conservation of white rhinoceros ( Ceratotherium simum ); however, cardiovascular responses in immobilized megaherbivores are poorly understood. Blood pressure and heart rate responses in rhinoceros immobilized with etorphine or etorphine plus azaperone, and the effects of subsequent i.v. butorphanol administration were investigated. Six white rhinoceros were used in a randomized crossover study design with four interventions: 1) etorphine i.m.; 2) etorphine plus azaperone i.m.; 3) etorphine i.m. and butorphanol i.v.; and 4) etorphine plus azaperone i.m., and butorphanol i.v. Etorphine resulted in hypertension and tachycardia in immobilized rhinoceros on initial measurements. Over the 25-min study period, blood pressures and heart rate declined. Heart rates were slower, although the rhinoceros were still tachycardic, and blood pressures lower during the whole study period in animals immobilized with etorphine and azaperone compared with those that received only etorphine. Butorphanol administration resulted in lower arterial blood pressures and heart rates in etorphine-immobilized rhinoceros. In rhinoceros immobilized with etorphine and azaperone, heart rate slowed following administration of butorphanol i.v., although blood pressures remained unchanged. Azaperone reduced hypertension associated with etorphine immobilization, but animals remained tachycardic. Administration of butorphanol to etorphine/azaperone-immoblized rhinoceros lowered heart rate to values approaching normal resting levels without altering blood pressure.
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Toledo C, Andrade DC, Lucero C, Schultz HD, Marcus N, Retamal M, Madrid C, Del Rio R. Contribution of peripheral and central chemoreceptors to sympatho-excitation in heart failure. J Physiol 2016; 595:43-51. [PMID: 27218485 DOI: 10.1113/jp272075] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 04/20/2016] [Indexed: 12/18/2022] Open
Abstract
Chronic heart failure (CHF) is a major public health problem. Tonic hyper-activation of sympathetic neural outflow is commonly observed in patients with CHF. Importantly, sympatho-excitation in CHF exacerbates its progression and is strongly related to poor prognosis and high mortality risk. Increases in both peripheral and central chemoreflex drive are considered markers of the severity of CHF. The principal peripheral chemoreceptors are the carotid bodies (CBs) and alteration in their function has been described in CHF. Mainly, during CHF the CB chemosensitivity is enhanced leading to increases in ventilation and sympathetic outflow. In addition to peripheral control of breathing, central chemoreceptors (CCs) are considered a dominant mechanism in ventilatory regulation. Potentiation of the ventilatory and sympathetic drive in response to CC activation has been shown in patients with CHF as well as in animal models. Therefore, improving understanding of the contribution of the peripheral and central chemoreflexes to augmented sympathetic discharge in CHF could help in developing new therapeutic approaches intended to attenuate the progression of CHF. Accordingly, the main focus of this review is to discuss recent evidence that peripheral and central chemoreflex function are altered in CHF and that they contribute to autonomic imbalance and progression of CHF.
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Affiliation(s)
- Camilo Toledo
- Laboratory of Cardiorespiratory Control, Center of Biomedical Research, Universidad Autónoma de Chile, Santiago, Chile
| | - David C Andrade
- Laboratory of Cardiorespiratory Control, Center of Biomedical Research, Universidad Autónoma de Chile, Santiago, Chile
| | - Claudia Lucero
- Laboratory of Cardiorespiratory Control, Center of Biomedical Research, Universidad Autónoma de Chile, Santiago, Chile
| | - Harold D Schultz
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, USA
| | - Noah Marcus
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, IA, USA
| | - Mauricio Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - Carlos Madrid
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Center of Biomedical Research, Universidad Autónoma de Chile, Santiago, Chile
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Barna BF, Takakura AC, Mulkey DK, Moreira TS. Purinergic receptor blockade in the retrotrapezoid nucleus attenuates the respiratory chemoreflexes in awake rats. Acta Physiol (Oxf) 2016; 217:80-93. [PMID: 26647910 DOI: 10.1111/apha.12637] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/06/2015] [Accepted: 11/26/2015] [Indexed: 01/21/2023]
Abstract
AIM Recent evidence suggests that adenosine triphosfate (ATP)-mediated purinergic signalling at the level of the rostral ventrolateral medulla contributes to both central and peripheral chemoreceptor control of breathing and blood pressure: neurones in the retrotrapezoid nucleus (RTN) function as central chemoreceptors in part by responding to CO2 -evoked ATP release by activation of yet unknown P2 receptors, and nearby catecholaminergic C1 neurones regulate blood pressure responses to peripheral chemoreceptor activation by a P2Y1 receptor-dependent mechanism. However, potential contributions of purinergic signalling in the RTN to cardiorespiratory function in conscious animals have not been tested. METHODS Cardiorespiratory activity of unrestrained awake rats was measured in response to RTN injections of ATP, and during exposure to hypercapnia (7% CO2 ) or hypoxia (8% O2 ) under control conditions and after bilateral RTN injections of P2 receptor blockers (PPADS or MRS2179). RESULTS Unilateral injection of ATP into the RTN increased cardiorespiratory output by a P2-receptor-dependent mechanism. We also show that bilateral RTN injections of a non-specific P2 receptor blocker (pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS) reduced the ventilatory response to hypercapnia (7% CO2 ) and hypoxia (8% O2 ) in unanesthetized rats. Conversely, bilateral injections of a specific P2Y1 receptor blocker (MRS2179) into the RTN had no measurable effect on ventilatory responses elicited by hypercapnia or hypoxia. CONCLUSION These data exclude P2Y1 receptor involvement in the chemosensory control of breathing at the level of the RTN and show that ATP-mediated purinergic signalling contributes to central and peripheral chemoreflex control of breathing and blood pressure in awake rats.
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Affiliation(s)
- B. F. Barna
- Department of Physiology and Biophysics; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
| | - A. C. Takakura
- Department of Pharmacology; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
| | - D. K. Mulkey
- Department of Physiology and Neurobiology; University of Connecticut; Storrs CT USA
| | - T. S. Moreira
- Department of Physiology and Biophysics; Institute of Biomedical Science; University of São Paulo; São Paulo SP Brazil
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Koeners MP, Lewis KE, Ford AP, Paton JF. Hypertension: a problem of organ blood flow supply-demand mismatch. Future Cardiol 2016; 12:339-49. [PMID: 27091483 PMCID: PMC4926521 DOI: 10.2217/fca.16.5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
This review introduces a new hypothesis that sympathetically mediated hypertensive diseases are caused, in the most part, by the activation of visceral afferent systems that are connected to neural circuits generating sympathetic activity. We consider how organ hypoperfusion and blood flow supply–demand mismatch might lead to both sensory hyper-reflexia and aberrant afferent tonicity. We discuss how this may drive sympatho-excitatory-positive feedback and extend across multiple organs initiating, or at least amplifying, sympathetic hyperactivity. The latter, in turn, compounds the challenge to sufficient organ blood flow through heightened vasoconstriction that both maintains and exacerbates hypertension.
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Affiliation(s)
- Maarten P Koeners
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Kirsty E Lewis
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
| | - Anthony P Ford
- Afferent Pharmaceuticals, 2929 Campus Drive, San Mateo, CA, USA
| | - Julian Fr Paton
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
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