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Shin MK, Tang WY, Amorim MR, Sham JSK, Polotsky VY. Carotid body denervation improves hyperglycemia in obese mice. J Appl Physiol (1985) 2024; 136:233-243. [PMID: 38126089 PMCID: PMC11219014 DOI: 10.1152/japplphysiol.00215.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 11/14/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
The carotid bodies (CBs) have been implicated in glucose abnormalities in obesity via elevation of activity of the sympathetic nervous system. Obesity-induced hypertension is mediated by insulin receptor (INSR) signaling and by leptin, which binds to the leptin receptor (LEPRb) in CB and activates transient receptor potential channel subfamily M member 7 (TRPM7). We hypothesize that in mice with diet-induced obesity, hyperglycemia, glucose intolerance, and insulin resistance will be attenuated by the CB denervation (carotid sinus nerve dissection, CSND) and by knockdown of Leprb, Trpm7, and Insr gene expression in CB. In series of experiments in 75 male diet-induced obese (DIO) mice, we performed either CSND (vs. sham) surgeries or shRNA-induced suppression of Leprb, Trpm7, or Insr gene expression in CB, followed by blood pressure telemetry, intraperitoneal glucose tolerance and insulin tolerance tests, and measurements of fasting plasma insulin, leptin, corticosterone, glucagon and free fatty acids (FFAs) levels, hepatic expression of gluconeogenesis enzymes phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G-6-Pase) mRNA and liver glycogen levels. CSND decreased blood pressure, fasting blood glucose levels and improved glucose tolerance without any effect on insulin resistance. CSND did not affect any hormone levels and gluconeogenesis enzymes, but increased liver glycogen level. Genetic knockdown of CB Leprb, Trpm7, and Insr had no effect on glucose metabolism. We conclude that CB contributes to hyperglycemia of obesity, probably by modulation of the glycogen-glucose equilibrium. Diabetogenic effects of obesity on CB in mice do not occur via activation of CB Leprb, Trpm7, and Insr.NEW & NOTEWORTHY This paper provides first evidence that carotid body denervation abolishes hypertension and improves fasting blood glucose levels and glucose tolerance in mice with diet-induced obesity. Furthermore, we have shown that this phenomenon is associated with increased liver glycogen content, whereas insulin sensitivity and enzymes of gluconeogenesis were not affected.
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Affiliation(s)
- Mi-Kyung Shin
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - Wan-Yee Tang
- Department of Environmental and Occupational Health, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States
| | - Mateus R Amorim
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
| | - James S-K Sham
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Vsevolod Y Polotsky
- Department of Anesthesiology and Critical Care Medicine, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, United States
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2
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Guimaraes DA, Aquino NSS, Rocha-Resende C, Jesus ICG, Silva MM, Scalzo SA, Fonseca RC, Durand MT, Pereira V, Tezini GCSV, Oliveira A, Prado VF, Stefanon I, Salgado HC, Prado MAM, Szawka RE, Guatimosim S. Neuronal cholinergic signaling constrains norepinephrine activity in the heart. Am J Physiol Cell Physiol 2022; 322:C794-C801. [PMID: 35264016 DOI: 10.1152/ajpcell.00031.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well known that cholinergic hypofunction contributes to cardiac pathology; yet, the mechanisms involved remain unclear. Our previous publication has shown that genetically engineered model of cholinergic deficit, the vesicular acetylcholine transporter knockdown homozygous (VAChT KDHOM) mice exhibit pathological cardiac remodeling and a gradual increase in cardiac mass with aging. Given that an increase in cardiac mass is often caused by adrenergic hyperactivity, we hypothesized that VAChT KDHOM mice might have an increase in cardiac norepinephrine (NE) levels. We thus investigated the temporal changes in NE content in the heart from 3, 6 and 12 month-old VAChT mutants. Interestingly, mice with cholinergic hypofunction showed a gradual elevation in cardiac NE content, which was already increased at 6 months of age. Consistent with this finding, 6 month-old VAChT KDHOM mice showed enhanced sympathetic activity and a greater abundance of tyrosine hydroxylase positive sympathetic nerves in the heart. VAChT mutants exhibited an increase in peak calcium transient, and mitochondrial oxidative stress in cardiomyocytes along with enhanced GRK5 and NFAT staining in the heart. These are known targets of adrenergic signaling in the cell. Moreover, vagotomized-mice displayed an increase in cardiac NE content confirming the data obtained in VAChT KDHOM mice. Establishing a causal relationship between acetylcholine and NE, VAChT KDHOM mice treated with pyridostigmine, a cholinesterase inhibitor, showed reduced cardiac NE content, rescuing the phenotype. Our findings unveil a yet unrecognized role of cholinergic signaling as a modulator of cardiac NE, providing novel insights into the mechanisms that drive autonomic imbalance.
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Affiliation(s)
- Diogo A Guimaraes
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Nayara S S Aquino
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Cibele Rocha-Resende
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Itamar C G Jesus
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Mário Morais Silva
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sergio A Scalzo
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Roberta Cristelli Fonseca
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marina T Durand
- Universidade de Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | - Vanessa Pereira
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - André Oliveira
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Vânia F Prado
- Robarts Research Institute, The University of Western Ontario, Department of Physiology 1and Pharmacology, Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Ivanita Stefanon
- Department of Physiological Sciences, Universidade Federal do Espírito Santo, Vitória, Espirito Santo, Brazil
| | - Helio C Salgado
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Marco Antonio Máximo Prado
- Robarts Research Institute, The University of Western Ontario, Department of Physiology 1and Pharmacology, Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Raphael E Szawka
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Silvia Guatimosim
- Department of Physiology and Biophysics, Institute of Biological Sciences, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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3
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Lu SF, Wang JM, Yuan J, Yang WX, Chen LY, Zhang T, Jing XY, Zhuang Y, Zhang CS, Fu SP, Yu ML. Electroacupuncture improves cardiac function and reduces infarct size by modulating cardiac autonomic remodeling in a mouse model of myocardial ischemia. Acupunct Med 2021; 39:681-690. [PMID: 34056953 DOI: 10.1177/09645284211009536] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Sympathetic and parasympathetic nerve remodeling play an important role in cardiac function after myocardial ischemia (MI) injury. Increasing evidence indicates that electroacupuncture (EA) can regulate cardiac function by modulating the autonomic nervous system (ANS), but little is known about its effectiveness on neural remodeling post-MI. OBJECTIVES To investigate the role of EA in ANS remodeling post-MI. METHODS Adult male C57/BL6 mice were equally divided into the Control (Ctrl), MI and EA groups after generating the MI model by ligating the left anterior descending (LAD) coronary artery. Echocardiography and 2,3,5-triphenyltetrazolium (TTC) staining were employed to evaluate cardiac function and infarct size after EA treatment for five consecutive days. Serum norepinephrine (NE) levels were measured by ELISA to quantify sympathetic activation. Then, ANS remodeling was detected by immunohistochemistry (IHC), RT-qPCR, and Western blotting. RESULTS Our preliminary findings showed that EA increased ejection fraction and fractional shortening and reduced infarct area after MI injury. Serum NE levels in the EA group were significantly decreased compared with those in the MI group. IHC staining results demonstrated that the density of growth associated protein (GAP)43 and tyrosine hydroxylase (TH) positive nerve fibers in the EA group were decreased with increased choline acetyltransferase (CHAT) and vesicular acetylcholine transporter (VACHT). Meanwhile, the results verified that mRNA and protein expression of GAP43 and TH were significantly inhibited by EA treatment in the MI mice, accompanied by elevated CHAT and VACHT. CONCLUSIONS EA treatment could improve cardiac function and reduce infarct size by modulating sympathetic and parasympathetic nerve remodeling post-MI, thus helping the cardiac ANS reach a new balance to try to protect the heart from further possible injury.
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Affiliation(s)
- Sheng-Feng Lu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jun-Meng Wang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jing Yuan
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Wen-Xiu Yang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Li-Yao Chen
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Tao Zhang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xin-Yue Jing
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yi Zhuang
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Cheng-Shun Zhang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shu-Ping Fu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
| | - Mei-Ling Yu
- Key Laboratory of Acupuncture and Medicine Research of Ministry of Education, Nanjing University of Chinese Medicine, Nanjing, China
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4
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Joviano-Santos JV, Kljakic O, Magalhães-Gomes MPS, Valadão PAC, de Oliveira LR, Prado MAM, Prado VF, Guatimosim C. Motoneuron-specific loss of VAChT mimics neuromuscular defects seen in congenital myasthenic syndrome. FEBS J 2021; 288:5331-5349. [PMID: 33730374 DOI: 10.1111/febs.15825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 03/03/2021] [Accepted: 03/16/2021] [Indexed: 11/28/2022]
Abstract
Motoneurons (MNs) control muscle activity by releasing the neurotransmitter acetylcholine (ACh) at the level of neuromuscular junctions. ACh is packaged into synaptic vesicles by the vesicular ACh transporter (VAChT), and disruptions in its release can impair muscle contraction, as seen in congenital myasthenic syndromes (CMS). Recently, VAChT gene mutations were identified in humans displaying varying degrees of myasthenia. Moreover, mice with a global deficiency in VAChT expression display several characteristics of CMS. Despite these findings, little is known about how a long-term decrease in VAChT expression in vivo affects MNs structure and function. Using Cre-loxP technology, we generated a mouse model where VAChT is deleted in select groups of MNs (mnVAChT-KD). Molecular analysis revealed that the VAChT deletion was specific to MNs and affected approximately 50% of its population in the brainstem and spinal cord, with alpha-MNs primarily targeted (70% in spinal cord). Within each animal, the cell body area of VAChT-deleted MNs was significantly smaller compared to MNs with VAChT preserved. Likewise, muscles innervated by VAChT-deleted MNs showed atrophy while muscles innervated by VAChT-containing neurons appeared normal. In addition, mnVAChT KD mice had decreased muscle strength, were hypoactive, leaner and exhibited kyphosis. This neuromuscular dysfunction was evident at 2 months of age and became progressively worse by 6 months. Treatment of mutants with a cholinesterase inhibitor was able to improve some of the motor deficits. As these observations mimic what is seen in CMS, this new line could be valuable for assessing the efficacy of potential CMS drugs.
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Affiliation(s)
- Julliane V Joviano-Santos
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ornela Kljakic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada
| | - Matheus P S Magalhães-Gomes
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Departamento de Medicina, Faculdade Ciências Médicas de Minas Gerais, FCMMG, Belo Horizonte, Brasil
| | - Priscila Aparecida C Valadão
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leonardo R de Oliveira
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marco A M Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Brain and Mind Institute, University of Western Ontario, London, Canada
| | - Vania F Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Brain and Mind Institute, University of Western Ontario, London, Canada
| | - Cristina Guatimosim
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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5
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Crotoxin-Induced Mice Lung Impairment: Role of Nicotinic Acetylcholine Receptors and COX-Derived Prostanoids. Biomolecules 2020; 10:biom10050794. [PMID: 32443924 PMCID: PMC7277605 DOI: 10.3390/biom10050794] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/13/2020] [Accepted: 03/14/2020] [Indexed: 12/12/2022] Open
Abstract
Respiratory compromise in Crotalus durissus terrificus (C.d.t.) snakebite is an important pathological condition. Considering that crotoxin (CTX), a phospholipase A2 from C.d.t. venom, is the main component of the venom, the present work investigated the toxin effects on respiratory failure. Lung mechanics, morphology and soluble markers were evaluated from Swiss male mice, and mechanism determined using drugs/inhibitors of eicosanoids biosynthesis pathway and autonomic nervous system. Acute respiratory failure was observed, with an early phase (within 2 h) characterized by enhanced presence of eicosanoids, including prostaglandin E2, that accounted for the increased vascular permeability in the lung. The alterations of early phase were inhibited by indomethacin. The late phase (peaked 12 h) was marked by neutrophil infiltration, presence of pro-inflammatory cytokines/chemokines, and morphological alterations characterized by alveolar septal thickening and bronchoconstriction. In addition, lung mechanical function was impaired, with decreased lung compliance and inspiratory capacity. Hexamethonium, a nicotinic acetylcholine receptor antagonist, hampered late phase damages indicating that CTX-induced lung impairment could be associated with cholinergic transmission. The findings reported herein highlight the impact of CTX on respiratory compromise, and introduce the use of nicotinic blockers and prostanoids biosynthesis inhibitors as possible symptomatic therapy to Crotalus durissus terrificus snakebite.
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6
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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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Verma AK, Xu D, Bruner M, Garg A, Goswami N, Blaber AP, Tavakolian K. Comparison of Autonomic Control of Blood Pressure During Standing and Artificial Gravity Induced via Short-Arm Human Centrifuge. Front Physiol 2018; 9:712. [PMID: 29988521 PMCID: PMC6026653 DOI: 10.3389/fphys.2018.00712] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Accepted: 05/23/2018] [Indexed: 12/11/2022] Open
Abstract
Autonomic control of blood pressure is essential toward maintenance of cerebral perfusion during standing, failure of which could lead to fainting. Long-term exposure to microgravity deteriorates autonomic control of blood pressure. Consequently, astronauts experience orthostatic intolerance on their return to gravitational environment. Ground-based studies suggest sporadic training in artificial hypergravity can mitigate spaceflight deconditioning. In this regard, short-arm human centrifuge (SAHC), capable of creating artificial hypergravity of different g-loads, provides an auspicious training tool. Here, we compare autonomic control of blood pressure during centrifugation creating 1-g and 2-g at feet with standing in natural gravity. Continuous blood pressure was acquired simultaneously from 13 healthy participants during supine baseline, standing, supine recovery, centrifugation of 1-g, and 2-g, from which heart rate (RR) and systolic blood pressure (SBP) were derived. The autonomic blood pressure regulation was assessed via spectral analysis of RR and SBP, spontaneous baroreflex sensitivity, and non-linear heart rate and blood pressure causality (RR↔SBP). While majority of these blood pressure regulatory indices were significantly different (p < 0.05) during standing and 2-g centrifugation compared to baseline, no change (p > 0.05) was observed in the same indices during 2-g centrifugation compared to standing. The findings of the study highlight the capability of artificial gravity (2-g at feet) created via SAHC toward evoking blood pressure regulatory controls analogous to standing, therefore, a potential utility toward mitigating deleterious effects of microgravity on cardiovascular performance and minimizing post-flight orthostatic intolerance in astronauts.
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Affiliation(s)
- Ajay K. Verma
- Department of Electrical Engineering, University of North Dakota, Grand Forks, ND, United States
| | - Da Xu
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Michelle Bruner
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Amanmeet Garg
- Department of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Nandu Goswami
- Physiology Division, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz, Graz, Austria
| | - Andrew P. Blaber
- Department of Electrical Engineering, University of North Dakota, Grand Forks, ND, United States
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Kouhyar Tavakolian
- Department of Electrical Engineering, University of North Dakota, Grand Forks, ND, United States
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
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Jaimes R, Swiercz A, Sherman M, Muselimyan N, Marvar PJ, Posnack NG. Plastics and cardiovascular health: phthalates may disrupt heart rate variability and cardiovascular reactivity. Am J Physiol Heart Circ Physiol 2017; 313:H1044-H1053. [PMID: 28842438 PMCID: PMC5792203 DOI: 10.1152/ajpheart.00364.2017] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 08/17/2017] [Accepted: 08/17/2017] [Indexed: 12/11/2022]
Abstract
Plastics have revolutionized medical device technology, transformed hematological care, and facilitated modern cardiology procedures. Despite these advances, studies have shown that phthalate chemicals migrate out of plastic products and that these chemicals are bioactive. Recent epidemiological and research studies have suggested that phthalate exposure adversely affects cardiovascular function. Our objective was to assess the safety and biocompatibility of phthalate chemicals and resolve the impact on cardiovascular and autonomic physiology. Adult mice were implanted with radiofrequency transmitters to monitor heart rate variability, blood pressure, and autonomic regulation in response to di-2-ethylhexyl-phthalate (DEHP) exposure. DEHP-treated animals displayed a decrease in heart rate variability (-17% SD of normal beat-to-beat intervals and -36% high-frequency power) and an exaggerated mean arterial pressure response to ganglionic blockade (31.5% via chlorisondamine). In response to a conditioned stressor, DEHP-treated animals displayed enhanced cardiovascular reactivity (-56% SD major axis Poincarè plot) and prolonged blood pressure recovery. Alterations in cardiac gene expression of endothelin-1, angiotensin-converting enzyme, and nitric oxide synthase may partly explain these cardiovascular alterations. This is the first study to show an association between phthalate chemicals that are used in medical devices with alterations in autonomic regulation, heart rate variability, and cardiovascular reactivity. Because changes in autonomic balance often precede clinical manifestations of hypertension, atherosclerosis, and conduction abnormalities, future studies are warranted to assess the downstream impact of plastic chemical exposure on end-organ function in sensitive patient populations. This study also highlights the importance of adopting safer biomaterials, chemicals, and/or surface coatings for use in medical devices.NEW & NOTEWORTHY Phthalates are widely used in the manufacturing of consumer and medical products. In the present study, di-2-ethylhexyl-phthalate exposure was associated with alterations in heart rate variability and cardiovascular reactivity. This highlights the importance of investigating the impact of phthalates on health and identifying suitable alternatives for medical device manufacturing.
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Affiliation(s)
- Rafael Jaimes
- 1Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, District of Columbia; ,2Children’s National Heart Institute, Children’s National Health System, Washington, District of Columbia; and
| | - Adam Swiercz
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Meredith Sherman
- 1Sheikh Zayed Institute for Pediatric Surgical Innovation, Children’s National Health System, Washington, District of Columbia;
| | - Narine Muselimyan
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Paul J. Marvar
- 3Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
| | - Nikki Gillum Posnack
- Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, District of Columbia; .,Children's National Heart Institute, Children's National Health System, Washington, District of Columbia; and.,Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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9
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Becari C, Durand MT, Guimaraes AO, Lataro RM, Prado CM, de Oliveira M, Candido SCO, Pais P, Ribeiro MS, Bader M, Pesquero JB, Salgado MCO, Salgado HC. Elastase-2, a Tissue Alternative Pathway for Angiotensin II Generation, Plays a Role in Circulatory Sympathovagal Balance in Mice. Front Physiol 2017; 8:170. [PMID: 28386233 PMCID: PMC5363176 DOI: 10.3389/fphys.2017.00170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 03/07/2017] [Indexed: 12/26/2022] Open
Abstract
In vitro and ex vivo experiments indicate that elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, is an alternative pathway for angiotensin II (Ang II) generation. However, the role played by ELA-2 in vivo is unclear. We examined ELA-2 knockout (ELA-2KO) mice compared to wild-type (WT) mice and determined whether ELA-2 played a role in hemodynamics [arterial pressure (AP) and heart rate (HR)], cardiocirculatory sympathovagal balance and baroreflex sensitivity. The variability of systolic arterial pressure (SAP) and pulse interval (PI) for evaluating autonomic modulation was examined for time and frequency domains (spectral analysis), whereas a symbolic analysis was also used to evaluate PI variability. In addition, baroreflex sensitivity was examined using the sequence method. Cardiac function was evaluated echocardiographically under anesthesia. The AP was normal whereas the HR was reduced in ELA-2KO mice (425 ± 17 vs. 512 ± 13 bpm from WT). SAP variability and baroreflex sensitivity were similar in both strains. The LF power from the PI spectrum (33.6 ± 5 vs. 51.8 ± 4.8 nu from WT) and the LF/HF ratio (0.60 ± 0.1 vs. 1.45 ± 0.3 from WT) were reduced, whereas the HF power was increased (66.4 ± 5 vs. 48.2 ± 4.8 nu from WT) in ELA-2KO mice, indicating a shift toward parasympathetic modulation of HR. Echocardiographic examination showed normal fractional shortening and an ejection fraction in ELA-2KO mice; however, the cardiac output, stroke volume, and ventricular size were reduced. These findings provide the first evidence that ELA-2 acts on the sympathovagal balance of the heart, as expressed by the reduced sympathetic modulation of HR in ELA-2KO mice.
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Affiliation(s)
- Christiane Becari
- Department of Physiology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Pharmacology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Cardiovascular Diseases, Mayo ClinicRochester, MN, USA
| | - Marina T Durand
- Department of Physiology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Medicine, University of Ribeirão PretoRibeirão Preto, Brazil
| | - Alessander O Guimaraes
- Max Delbruck Center for Molecular MedicineBerlin, Germany; Department of Biophysics, Federal University of São PauloSão Paulo, Brazil
| | - Renata M Lataro
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Cibele M Prado
- Department of Pathology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Mauro de Oliveira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Sarai C O Candido
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Paloma Pais
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Mauricio S Ribeiro
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Michael Bader
- Max Delbruck Center for Molecular MedicineBerlin, Germany; Berlin Institute of Health, Charité-University Medicine BerlinBerlin, Germany; German Center for Cardiovascular Research, Partner Site BerlinBerlin, Germany
| | - Joao B Pesquero
- Department of Biophysics, Federal University of São Paulo São Paulo, Brazil
| | - Maria C O Salgado
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
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