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Szabó P, Bonet S, Hetényi R, Hanna D, Kovács Z, Prisztóka G, Križalkovičová Z, Szentpéteri J. Systematic review: pain, cognition, and cardioprotection-unpacking oxytocin's contributions in a sport context. Front Physiol 2024; 15:1393497. [PMID: 38915776 PMCID: PMC11194439 DOI: 10.3389/fphys.2024.1393497] [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: 03/01/2024] [Accepted: 05/13/2024] [Indexed: 06/26/2024] Open
Abstract
Introduction This systematic review investigates the interplay between oxytocin and exercise; in terms of analgesic, anti-inflammatory, pro-regenerative, and cardioprotective effects. Furthermore, by analyzing measurement methods, we aim to improve measurement validity and reliability. Methods Utilizing PRISMA, GRADE, and MECIR protocols, we examined five databases with a modified SPIDER search. Including studies on healthy participants, published within the last 20 years, based on keywords "oxytocin," "exercise" and "measurement," 690 studies were retrieved initially (455 unique records). After excluding studies of clinically identifiable diseases, and unpublished and reproduction-focused studies, 175 studies qualified for the narrative cross-thematic and structural analysis. Results The analysis resulted in five categories showing the reciprocal impact of oxytocin and exercise: Exercise (50), Physiology (63), Environment (27), Social Context (65), and Stress (49). Exercise-induced oxytocin could promote tissue regeneration, with 32 studies showing its analgesic and anti-inflammatory effects, while 14 studies discussed memory and cognition. Furthermore, empathy-associated OXTR rs53576 polymorphism might influence team sports performance. Since dietary habits and substance abuse can impact oxytocin secretion too, combining self-report tests and repeated salivary measurements may help achieve precision. Discussion Oxytocin's effect on fear extinction and social cognition might generate strategies for mental training, and technical, and tactical development in sports. Exercise-induced oxytocin can affect the amount of stress experienced by athletes, and their response to it. However, oxytocin levels could depend on the type of sport in means of contact level, exercise intensity, and duration. The influence of oxytocin on athletes' performance and recovery could have been exploited due to its short half-life. Examining oxytocin's complex interactions with exercise paves the way for future research and application in sports science, psychology, and medical disciplines. Systematic Review Registration https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=512184, identifier CRD42024512184.
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Affiliation(s)
- Péter Szabó
- Faculty of Sciences, Institute of Sports Science and Physical Education, University of Pécs, Pécs, Hungary
- Faculty of Humanities, University of Pécs, Pécs, Hungary
- Medical School, Institute of Transdisciplinary Discoveries, University of Pécs, Pécs, Hungary
| | - Sara Bonet
- Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Roland Hetényi
- RoLink Biotechnology Kft., Pécs, Hungary
- Hungarian National Blood Transfusion Service, Budapest, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- National Virology Laboratory, University of Pécs, Pécs, Hungary
| | - Dániel Hanna
- RoLink Biotechnology Kft., Pécs, Hungary
- Hungarian National Blood Transfusion Service, Budapest, Hungary
- Szentágothai Research Centre, University of Pécs, Pécs, Hungary
- National Virology Laboratory, University of Pécs, Pécs, Hungary
| | - Zsófia Kovács
- Faculty of Sciences, Institute of Sports Science and Physical Education, University of Pécs, Pécs, Hungary
| | - Gyöngyvér Prisztóka
- Faculty of Sciences, Institute of Sports Science and Physical Education, University of Pécs, Pécs, Hungary
| | - Zuzana Križalkovičová
- Faculty of Health Sciences, Institute of Physiotherapy and Sport Science, Department of Sport Science, Pécs, Hungary
| | - József Szentpéteri
- Medical School, Institute of Transdisciplinary Discoveries, University of Pécs, Pécs, Hungary
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Santiago HP, Leite LHR, Lima PMA, Fóscolo DRC, Natali AJ, Prímola-Gomes TN, Szawka RE, Coimbra CC. Effects of physical training on hypothalamic neuronal activation and expressions of vasopressin and oxytocin in SHR after running until fatigue. Pflugers Arch 2024; 476:365-377. [PMID: 38308122 DOI: 10.1007/s00424-024-02916-1] [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: 11/14/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
To assess the influence of physical training on neuronal activation and hypothalamic expression of vasopressin and oxytocin in spontaneously hypertensive rats (SHR), untrained and trained normotensive rats and SHR were submitted to running until fatigue while internal body and tail temperatures were recorded. Hypothalamic c-Fos expression was evaluated in thermoregulatory centers such as the median preoptic nucleus (MnPO), medial preoptic nucleus (mPOA), paraventricular nucleus of the hypothalamus (PVN), and supraoptic nucleus (SON). The PVN and the SON were also investigated for vasopressin and oxytocin expressions. Although exercise training improved the workload performed by the animals, it was reduced in SHR and followed by increased internal body temperature due to tail vasodilation deficit. Physical training enhanced c-Fos expression in the MnPO, mPOA, and PVN of both strains, and these responses were attenuated in SHR. Vasopressin immunoreactivity in the PVN was also increased by physical training to a lesser extent in SHR. The already-reduced oxytocin expression in the PVN of SHR was increased in response to physical training. Within the SON, neuronal activation and the expressions of vasopressin and oxytocin were reduced by hypertension and unaffected by physical training. The data indicate that physical training counterbalances in part the negative effect of hypertension on hypothalamic neuronal activation elicited by exercise, as well as on the expression of vasopressin and oxytocin. These hypertension features seem to negatively influence the workload performed by SHR due to the hyperthermia derived from the inability of physical training to improve heat dissipation through skin vasodilation.
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Affiliation(s)
- Henrique P Santiago
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Laura H R Leite
- Departamento de Biofísica e Fisiologia, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil
| | - Paulo M A Lima
- Núcleo de Pesquisa da Faculdade de Medicina da Universidade de Rio Verde, Universidade de Rio Verde, Campus Goiânia, Goiânia, Brazil
| | - Daniela R C Fóscolo
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Antônio José Natali
- Departamento de Educação Física, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil
| | | | - Raphael E Szawka
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Cândido C Coimbra
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil.
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Dellacqua LO, Gomes PM, Batista JS, Michelini LC, Antunes VR. Exercise-induced neuroplasticity in autonomic nuclei restores the cardiac vagal tone and baroreflex dysfunction in aged hypertensive rats. J Appl Physiol (1985) 2024; 136:189-198. [PMID: 38059293 DOI: 10.1152/japplphysiol.00433.2023] [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: 06/30/2023] [Revised: 11/29/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023] Open
Abstract
Aging is accompanied by considerable deterioration of homeostatic systems, such as autonomic imbalance characterized by heightened sympathetic activity, lower parasympathetic tone, and depressed heart rate (HR) variability, which are aggravated by hypertension. Here, we hypothesized that these age-related deficits in aged hypertensive rats can be ameliorated by exercise training, with benefits to the cardiovascular system. Therefore, male 22-mo-old spontaneously hypertensive rats (SHRs) and age-matched Wistar Kyoto (WKY) submitted to moderate-intensity exercise training (T) or kept sedentary (S) for 8 wk were evaluated for hemodynamic/autonomic parameters, baroreflex sensitivity, cardiac sympathetic/parasympathetic tone and analysis of dopamine β-hydroxylase (DBH+) and oxytocin (OT+) pathways of autonomic brain nuclei. Aged SHR-S versus WKY-S exhibited elevated mean arterial pressure (MAP: +51%) and HR (+20%), augmented pressure/HR variability, no cardiac vagal tone, and depressed reflex control of the heart (HR range, -28%; gain, -49%). SHR-T exhibited a lower resting HR, a partial reduction in the MAP (-14%), in the pressure/HR variabilities, and restored parasympathetic modulation, with improvement of baroreceptor reflex control when compared with SHR-S. Exercise training increased the ascending DBH+ projections conveying peripheral information to the paraventricular nucleus of hypothalamus (PVN), augmented the expression of OT+ neurons, and reduced the density of DBH+ neurons in the rostral ventrolateral medulla (RVLM) of SHR-T. Data indicate that exercise training induces beneficial neuroplasticity in brain autonomic circuitry, and it is highly effective to restore the parasympathetic tone, and attenuation of age-related autonomic imbalance and baroreflex dysfunction, thus conferring long-term benefits for cardiovascular control in aged hypertensive individuals.NEW & NOTEWORTHY Exercise training reduces high blood pressure and cardiovascular autonomic modulation in aged hypertensive rats. The dysfunction in the baroreflex sensitivity and impaired parasympathetic tone to the heart of aged hypertensive rats are restored by exercise training. Exercise induces beneficial neuroplasticity in the brain nuclei involved with autonomic control of cardiovascular function of aged hypertensive rats.
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Affiliation(s)
- Lais Oliveira Dellacqua
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Paula Magalhães Gomes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Julia Santos Batista
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Lisete Compagno Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Vagner Roberto Antunes
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
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Candido VB, Perego SM, Ceroni A, Metzger M, Colquhoun A, Michelini LC. Trained hypertensive rats exhibit decreased transcellular vesicle trafficking, increased tight junctions' density, restored blood-brain barrier permeability and normalized autonomic control of the circulation. Front Physiol 2023; 14:1069485. [PMID: 36909225 PMCID: PMC9997677 DOI: 10.3389/fphys.2023.1069485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 02/14/2023] [Indexed: 02/25/2023] Open
Abstract
Introduction: Chronic hypertension is accompanied by either blood-brain barrier (BBB) leakage and autonomic dysfunction. There is no consensus on the mechanism determining increased BBB permeability within autonomic areas. While some reports suggested tight junction's breakdown, others indicated the involvement of transcytosis rather than paracellular transport changes. Interestingly, exercise training was able to restore both BBB permeability and autonomic control of the circulation. We sought now to clarify the mechanism(s) governing hypertension- and exercise-induced BBB permeability. Methods: Spontaneously hypertensive rats (SHR) and normotensive controls submitted to 4-week aerobic training (T) or sedentary protocol (S) were chronically cannulated for baseline hemodynamic and autonomic recordings and evaluation of BBB permeability. Brains were harvested for measurement of BBB function (FITC-10 kDa leakage), ultrastructural analysis of BBB constituents (transmission electron microscopy) and caveolin-1 expression (immunofluorescence). Results: In SHR-S the increased pressure, augmented sympathetic vasomotor activity, higher sympathetic and lower parasympathetic modulation of the heart and the reduced baroreflex sensitivity were accompanied by robust FITC-10kDa leakage, large increase in transcytotic vesicles number/capillary, but no change in tight junctions' density within the paraventricular nucleus of the hypothalamus, the nucleus of the solitary tract and the rostral ventrolateral medulla. SHR-T exhibited restored BBB permeability and normalized vesicles counting/capillary simultaneously with a normal autonomic modulation of heart and vessels, resting bradycardia and partial pressure reduction. Caveolin-1 expression ratified the counting of transcellular, not other cytoplasmatic vesicles. Additionally, T caused in both groups significant increases in tight junctions' extension/capillary border. Discussion: Data indicate that transcytosis, not the paracellular transport, is the primary mechanism underlying both hypertension- and exercise-induced BBB permeability changes within autonomic areas. The reduced BBB permeability contributes to normalize the autonomic control of the circulation, which suppresses pressure variability and reduces the occurrence of end-organ damage in the trained SHR. Data also disclose that hypertension does not change but exercise training strengthens the resistance of the paracellular pathway in both strains.
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Affiliation(s)
| | - Sany M Perego
- Department of Physiology and Biophysics, São Paulo, Brazil
| | | | - Martin Metzger
- Department of Physiology and Biophysics, São Paulo, Brazil
| | - Alison Colquhoun
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, São Paulo, Brazil
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Raquel HA, Manica LA, Ceroni A, Michelini LC. Exercise training improves cardiovascular control in sinoaortic denervated SHR by reducing the elevated angiotensin II and augmenting angiotensin-(1-7) availability within autonomic and neuroendocrine PVN nuclei. Peptides 2022; 153:170798. [PMID: 35405300 DOI: 10.1016/j.peptides.2022.170798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 11/18/2022]
Abstract
Previous studies have shown that baroreceptors- and chemoreceptors-denervated SHR exhibit impaired central autonomic circuitry and worsening of the cardiovascular function. It was also known that exercise training (T) ameliorates the autonomic control of the circulation. In the present study we sought to investigate whether sinoaortic denervation (SAD) is able to modify the expression/activity of the renin-angiotensin system (RAS) within brain autonomic areas and the effects induced by T. SHR submitted to SAD or SHAM surgery were trained or kept sedentary (S) for 8 weeks. Femoral artery and vein were chronically cannulated for hemodynamic/autonomic recordings and baroreflex testing (phenylephrine and sodium nitroprusside, i.v). Ang II and Ang (1-7) protein expression (immunofluorescence assays) were quantified within autonomic and neuroendocrine nuclei of the hypothalamic paraventricular nucleus (PVN). SAD-S vs. SHAM-S exhibited large increase in Ang II availability into the ventromedial, dorsal cap and magnocellular PVN nuclei, which are accompanied by augmented sympathetic activity, elevated arterial pressure variability and higher MAP. There was no change in Ang-(1-7) content within these nuclei. In contrast, T largely augmented Ang-(1-7) immunofluorescence in all nuclei, reduced and normalized Ang II availability and ameliorated the autonomic control of the circulation in SAD rats, but did not reduce MAP levels. Data showed that tonic baroreceptors and chemoreceptors' activity is essential to maintain lower Ang II levels within PVN nuclei. In the absence of afferent signaling, exercise training is still efficient to alter Ang II/Ang-(1-7) balance thus improving cardiovascular control even in the presence of high-pressure levels.
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Affiliation(s)
- Hiviny A Raquel
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil.
| | - Louisi A Manica
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
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Kay MW, Jain V, Panjrath G, Mendelowitz D. Targeting Parasympathetic Activity to Improve Autonomic Tone and Clinical Outcomes. Physiology (Bethesda) 2022; 37:39-45. [PMID: 34486396 PMCID: PMC8742722 DOI: 10.1152/physiol.00023.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In this review we will briefly summarize the evidence that autonomic imbalance, more specifically reduced parasympathetic activity to the heart, generates and/or maintains many cardiorespiratory diseases and will discuss mechanisms and sites, from myocytes to the brain, that are potential translational targets for restoring parasympathetic activity and improving cardiorespiratory health.
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Affiliation(s)
- Matthew W. Kay
- 1Department of Biomedical Engineering, George Washington University, Washington, District of Columbia
| | - Vivek Jain
- 2Division of Pulmonary Medicine, Department of Medicine, George Washington University, Washington, District of Columbia
| | - Gurusher Panjrath
- 3Division of Cardiology, Department of Medicine, George Washington University, Washington, District of Columbia
| | - David Mendelowitz
- 4Department of Pharmacology and Physiology, George Washington University, Washington, District of Columbia
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Jordão MT, Ceroni A, Michelini LC. Perfusion of Brain Preautonomic Areas in Hypertension: Compensatory Absence of Capillary Rarefaction and Protective Effects of Exercise Training. Front Physiol 2021; 12:773415. [PMID: 34975525 PMCID: PMC8716837 DOI: 10.3389/fphys.2021.773415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/19/2021] [Indexed: 11/18/2022] Open
Abstract
Remodeling of capillary rarefaction and deleterious arteries are characteristic hallmarks of hypertension that are partially corrected by exercise training. In addition, experimental evidence showed capillary rarefaction within the brain cortex and reduced cerebral blood flow. There is no information on hypertension- and exercise-induced effects on capillary profile and function within preautonomic nuclei. We sought now to evaluate the effects of hypertension and exercise training (T) on the capillary network within hypothalamic paraventricular (PVN) and solitary tract (NTS) nuclei, and on the remodeling of brain arteries. Age-matched spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY), submitted to moderate T or kept sedentary (S) for three months, were chronically cannulated for hemodynamic recordings at rest. Rats were anesthetized for i.v. administration of fluorescein isothiocyanate (FITC)-dextran (capillary volume/density measurements) or 4% paraformaldehyde perfusion (basilar, middle, and posterior arteries' morphometry) followed by brain harvesting and processing. Other groups of conscious rats had carotid blood flow (CBF, ultrasound flowmeter) acquired simultaneously with hemodynamic recordings at rest and exercise. SHR-S exhibited elevated pressure and heart rate, reduced CBF, increased wall/lumen ratio of arteries, but no capillary rarefaction within the PVN and NTS. T improved performance gain and caused resting bradycardia in both groups; reduction of pressure and sympathetic vasomotor activity and normalization of the wall/lumen ratio were only observed in SHR-T. T groups responded with marked PVN and NTS capillary angiogenesis and augmented CBF during exercise; to avoid overperfusion at rest, reduced basal CBF was observed only in WKY-T. Data indicated that the absence of SHR-S capillary rarefaction and the intense SHR-T angiogenesis within autonomic areas associated with correction of deleterious arteries' remodeling are essential adjustments to hypertension and exercise training, respectively. These adaptive responses maintain adequate baseline perfusion in SHR-S and SHR-T preautonomic nuclei, augmenting it in exercised rats when a well-coordinated autonomic control is required.
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Affiliation(s)
- Maria Tereza Jordão
- Department Physiology & Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
- Santa Cecilia University (UNISANTA), Santos, Brazil
| | - Alexandre Ceroni
- Department Physiology & Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Lisete C. Michelini
- Department Physiology & Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
- *Correspondence: Lisete C. Michelini ; orcid.org/0000-0003-2978-5406
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Fragas MG, Cândido VB, Davanzo GG, Rocha-Santos C, Ceroni A, Michelini LC. Transcytosis within PVN capillaries: a mechanism determining both hypertension-induced blood-brain barrier dysfunction and exercise-induced correction. Am J Physiol Regul Integr Comp Physiol 2021; 321:R732-R741. [PMID: 34549626 DOI: 10.1152/ajpregu.00154.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/17/2021] [Indexed: 11/22/2022]
Abstract
Although hypertension disrupts the blood-brain barrier (BBB) integrity within the paraventricular nucleus of hypothalamus (PVN) and increases the leakage into the brain parenchyma, exercise training (T) was shown to correct it. Since there is scarce and contradictory information on the mechanism(s) determining hypertension-induced BBB deficit and nothing is known about T-induced improvement, we sought to evaluate the paracellular and transcellular transport across the BBB within the PVN in both conditions. Spontaneously hypertensive rats (SHR) and WKY submitted to 4-wk aerobic T or sedentary (S) protocol were chronically catheterized for hemodynamic recordings at rest and intra-arterial administration of dyes (Rhodamine-dextran 70 kDa + FITC-dextran 10 kDa). Brains were harvesting for FITC leakage examination, qPCR evaluation of different BBB constituents and protein expression of caveolin-1 and claudin-5, the main markers of transcytosis and paracellular transport, respectively. Hypertension was characterized by increased arterial pressure and heart rate, augmented sympathetic modulation of heart and vessels, and reduced cardiac parasympathetic control, marked FITC extravasation into the PVN which was accompanied by increased caveolin-1 gene and protein expression, without changes in claudin-5 and others tight junctions' components. SHR-T vs. SHR-S showed a partial pressure reduction, resting bradycardia, improvement of autonomic control of the circulation simultaneously with correction of both FITC leakage and caveolin-1 expression; there was a significant increase in claudin-5 expression. Caveolin-1 content was strongly correlated with improved autonomic control after exercise. Data indicated that within the PVN the transcytosis is the main mechanism governing both hypertension-induced BBB leakage, as well as the exercise-induced correction.
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Affiliation(s)
- Matheus Garcia Fragas
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Vanessa Brito Cândido
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Gustavo Gastão Davanzo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Carla Rocha-Santos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
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Feitosa LADS, Carvalho JDS, Dantas CO, de Souza DS, de Vasconcelos CML, Miguel-Dos-Santos R, Lauton-Santos S, Quíntans-Júnior LJ, Santos MRV, de Santana-Filho VJ, Barreto AS. Resistance training improves cardiac function and cardiovascular autonomic control in doxorubicin-induced cardiotoxicity. Cardiovasc Toxicol 2021; 21:365-374. [PMID: 33387253 DOI: 10.1007/s12012-020-09627-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/14/2020] [Indexed: 02/02/2023]
Abstract
Doxorubicin (DOX) is an anticancer chemotherapy drug that is widely used in clinical practice. It is well documented that DOX impairs baroreflex responsiveness and left ventricular function and enhances sympathetic activity, cardiac sympathetic afferent reflexes and oxidative stress, which contribute to hemodynamic deterioration. Because resistance training (RT)-induced cardioprotection has been observed in other animal models, the objective of this study was to assess the effects of RT during DOX treatment on hemodynamics, arterial baroreflex, cardiac autonomic tone, left ventricular function and oxidative stress in rats with DOX-induced cardiotoxicity. Male Wistar rats were submitted to a RT protocol (3 sets of 10 repetitions, 40% of one-repetition maximum (1RM) of intensity, 3 times per week, for 8 weeks). The rats were separated into 3 groups: sedentary control, DOX sedentary (2.5 mg/kg of DOX intraperitoneal injection, once a week, for 6 weeks) and DOX + RT. After training or time control, the animals were anesthetized and 2 catheters were implanted for hemodynamic, arterial baroreflex and cardiac autonomic tone. Another group of animals was used to evaluate left ventricular function. We found that RT in DOX-treated rats decreased diastolic arterial pressure, heart rate, sympathetic tone and oxidative stress. In addition, RT increased arterial baroreflex sensitivity, vagal tone and left ventricular developed pressure in rats with DOX-induced cardiotoxicity. In summary, RT is a useful non-pharmacological strategy to attenuate DOX-induced cardiotoxicity.
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Affiliation(s)
| | | | - Cácia Oliveira Dantas
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | - Diego Santos de Souza
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | | | - Rodrigo Miguel-Dos-Santos
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
- Cardiac Exercise Research Group, Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sandra Lauton-Santos
- Department of Physiology, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil
| | | | | | | | - André Sales Barreto
- Department of Health Education, Federal University of Sergipe, Lagarto, Sergipe, Brazil
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de Ataides Raquel H, Souza Guazelli CF, Verri WA, Michelini LC, Martins-Pinge MC. Swimming training reduces iNOS expression, augments the antioxidant defense and reduces sympathetic responsiveness in the rostral ventrolateral medulla of normotensive male rats. Brain Res Bull 2021; 170:225-233. [PMID: 33631270 DOI: 10.1016/j.brainresbull.2021.02.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 11/30/2022]
Abstract
We sought to investigate whether RVLM iNOS activity and oxidative profile may participate in the reduction of sympathetic responsiveness in swimming trained normotensive rats. Sedentary (S) and swimming trained (T) Wistar male rats chronically instrumented with an arterial catheter and guide cannula into the RVLM were submitted to continuous pressure and heart rate (HR) recordings and determination of autonomic control (power spectral analysis) before and after unilateral RVLM iNOS inhibition (aminoguanidine, 250 pmol/100 nL). Other S and T rats received local l-glutamate microinjection (5 nmol/100 nL). In separate S and T groups not submitted to brainstem cannulation, fresh bilateral RVLM punchs were collected for iNOS gene expression (qPCR); reduced glutathione and lipid peroxidation quantification (spectrophotometry); iron-reducing antioxidant (FRAP) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS˙+) scavenger assays. iNOS gene expression was confirmed in fixed RVLM slices (immunofluorescence). T rats exhibited resting bradycardia, lower sympathovagal balance, reduced RVLM iNOS gene/protein expression and higher antioxidant capacity. Decreased iNOS expression was positively correlated with reduced HR. Pressor and tachycardic response to l-Glutamate were smaller in T rats. Aminoguanidine microinjection reduced sympathetic activity in S rats but did not change it in T rats expressing reduced RVLM iNOS content. Our data indicate that iNOS, expressed in the RVLM of normotensive male rats, has tonic effects on sympathetic activity and that swimming training is an efficient tool to reduce iNOS expression and augment the antioxidant defense, thus reducing glutamatergic responsiveness and sympathetic drive to cardiovascular effectors.
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Affiliation(s)
- Hiviny de Ataides Raquel
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil; Departament of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Carla Fabiana Souza Guazelli
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Waldiceu A Verri
- Departament of Pathological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil
| | - Lisete C Michelini
- Departament of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Marli Cardoso Martins-Pinge
- Departament of Physiological Sciences, Center of Biological Sciences, State University of Londrina, Londrina, PR, Brazil.
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11
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Ferreira-Junior NC, Ruggeri A, Silva SD, Zampieri TT, Ceroni A, Michelini LC. Exercise training increases GAD65 expression, restores the depressed GABA A receptor function within the PVN and reduces sympathetic modulation in hypertension. Physiol Rep 2020; 7:e14107. [PMID: 31264387 PMCID: PMC6603325 DOI: 10.14814/phy2.14107] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/09/2019] [Indexed: 11/24/2022] Open
Abstract
GABAergic inhibitory input within the paraventricular hypothalamic nucleus (PVN) plays a key role in restraining sympathetic outflow. Although experimental evidence has shown depressed GABAA receptor function plus sympathoexcitation in hypertension and augmented GABA levels with reduced sympathetic activity after exercise training (T), the mechanisms underlying T‐induced effects remain unclear. Here we investigated in T and sedentary (S) SHR and WKY: (1) time‐course changes of hemodynamic parameters and PVN glutamic acid decarboxylase (GAD) isoforms’ expression; (2) arterial pressure (AP) and heart rate (HR) responses, sympathetic/parasympathetic modulation of heart and vessels and baroreflex sensitivity to GABAA receptor blockade within the PVN. SHR‐S versus WKY‐S exhibited higher AP and HR, increased sympathetic reduced parasympathetic modulation, smaller baroreflex sensitivity, and reduced PVN GAD65 immunoreactivity. SHR‐T and WKY‐T showed prompt maintained increase (2–8 weeks) in GAD65 expression (responsible for GABA vesicular pool synthesis), which occurred simultaneously with HR reduction in SHR‐T and preceded MAP fall in SHR‐T and resting bradycardia in WKY‐T. There was no change in GAD67 expression (mainly involved with GABA metabolic pool). Resting HR in both groups and basal MAP in SHR were negatively correlated with PVN GAD65 expression. Normalized baroreflex sensitivity and autonomic control observed only in SHR‐T were due to recovery of GABAA receptor function into the PVN since bicuculline administration abolished these effects. Data indicated that training augments in both groups the expression/activity of GABAergic neurotransmission within presympathetic PVN neurons and restores GABAA receptors′ function specifically in the SHR, therefore strengthening GABAergic modulation of sympathetic outflow in hypertension.
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Affiliation(s)
- Nilson C Ferreira-Junior
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Adriana Ruggeri
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Sebastião D Silva
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Thais T Zampieri
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Alexandre Ceroni
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Lisete C Michelini
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, SP, Brazil
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12
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Rocha-Santos C, Braga DC, Ceroni A, Michelini LC. Activity-Dependent Neuroplastic Changes in Autonomic Circuitry Modulating Cardiovascular Control: The Essential Role of Baroreceptors and Chemoreceptors Signaling. Front Physiol 2020; 11:309. [PMID: 32328002 PMCID: PMC7160511 DOI: 10.3389/fphys.2020.00309] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 03/19/2020] [Indexed: 01/09/2023] Open
Abstract
Aerobic exercise training improves the autonomic control of the circulation. Emerging evidence has shown that exercise induces neuroplastic adaptive changes in preautonomic circuitry controlling sympathetic/parasympathetic outflow to heart and vessels. The mechanisms underlying neuronal plasticity are, however, incompletely understood. Knowing that sinoaortic denervation blocks training-induced cardiovascular benefits, we investigate whether baroreceptors’ and chemoreceptors’ signaling are able to drive neuronal plasticity within medullary and supramedullary pathways controlling autonomic outflow. Male Wistar rats submitted to sinoaortic denervation (SAD) or dopamine β-hydroxylase-saporin lesion (DBHx) and respective controls (SHAM) were allocated to training (T) or sedentary (S) protocols for 8 weeks. After hemodynamic measurements at rest, rats were deeply anesthetized for brain harvesting. The density of DBH and oxytocin (OT) cell bodies and terminals were analyzed in brainstem and hypothalamic brain areas (double immunofluorescence reactions, optic and confocal microscopy). In SHAM rats training augmented the density of DBH+ neurons in the nucleus of solitary tract, increased the density of ascending NORergic projections and the number of DBH+ boutons contacting preautonomic OT+ neurons into paraventricular hypothalamic preautonomic nuclei, augmented the density of local OTergic neurons and enhanced the density of OT+ terminals targeting brainstem autonomic areas. These plastic changes occurred simultaneously with reduced sympathetic/increased parasympathetic activity, augmented baroreflex sensitivity and reduced resting heart rate. SAD reduced the density of both DBH+ fibers ascending from brainstem to paraventricular nucleus of hypothalamus and preautonomic OT+ neurons projecting to the brainstem, abrogated training-induced plastic changes and autonomic adaptive responses without changing the treadmill performance. Minor neuroplastic changes with preserved baroreflex sensitivity were observed in trained rats after partial selective disruption of ascending NORergic projections. Our data indicated that afferent inputs conveyed by arterial baroreceptors and chemoreceptors are the main stimuli to drive both inactivity-induced and activity-dependent neuroplasticity within the autonomic circuitry.
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Affiliation(s)
- Carla Rocha-Santos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Douglas Costa Braga
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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13
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Wang P, Wang SC, Yang H, Lv C, Jia S, Liu X, Wang X, Meng D, Qin D, Zhu H, Wang YF. Therapeutic Potential of Oxytocin in Atherosclerotic Cardiovascular Disease: Mechanisms and Signaling Pathways. Front Neurosci 2019; 13:454. [PMID: 31178679 PMCID: PMC6537480 DOI: 10.3389/fnins.2019.00454] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/23/2019] [Indexed: 12/12/2022] Open
Abstract
Coronary artery disease (CAD) is a major cardiovascular disease responsible for high morbidity and mortality worldwide. The major pathophysiological basis of CAD is atherosclerosis in association with varieties of immunometabolic disorders that can suppress oxytocin (OT) receptor (OTR) signaling in the cardiovascular system (CVS). By contrast, OT not only maintains cardiovascular integrity but also has the potential to suppress and even reverse atherosclerotic alterations and CAD. These protective effects of OT are associated with its protection of the heart and blood vessels from immunometabolic injuries and the resultant inflammation and apoptosis through both peripheral and central approaches. As a result, OT can decelerate the progression of atherosclerosis and facilitate the recovery of CVS from these injuries. At the cellular level, the protective effect of OT on CVS involves a broad array of OTR signaling events. These signals mainly belong to the reperfusion injury salvage kinase pathway that is composed of phosphatidylinositol 3-kinase-Akt-endothelial nitric oxide synthase cascades and extracellular signal-regulated protein kinase 1/2. Additionally, AMP-activated protein kinase, Ca2+/calmodulin-dependent protein kinase signaling and many others are also implicated in OTR signaling in the CVS protection. These signaling events interact coordinately at many levels to suppress the production of inflammatory cytokines and the activation of apoptotic pathways. A particular target of these signaling events is endoplasmic reticulum (ER) stress and mitochondrial oxidative stress that interact through mitochondria-associated ER membrane. In contrast to these protective effects and machineries, rare but serious cardiovascular disturbances were also reported in labor induction and animal studies including hypotension, reflexive tachycardia, coronary spasm or thrombosis and allergy. Here, we review our current understanding of the protective effect of OT against varieties of atherosclerotic etiologies as well as the approaches and underlying mechanisms of these effects. Moreover, potential cardiovascular disturbances following OT application are also discussed to avoid unwanted effects in clinical trials of OT usages.
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Affiliation(s)
- Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Stephani C Wang
- Department of Medicine, Albany Medical Center, Albany, NY, United States
| | - Haipeng Yang
- Department of Pediatrics, The Forth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Chunmei Lv
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Dexin Meng
- Department of Physiology, Jiamusi University, Jiamusi, China
| | - Danian Qin
- Department of Physiology, Shantou University of Medical College, Shantou, China
| | - Hui Zhu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
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14
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Dampney RA, Michelini LC, Li DP, Pan HL. Regulation of sympathetic vasomotor activity by the hypothalamic paraventricular nucleus in normotensive and hypertensive states. Am J Physiol Heart Circ Physiol 2018; 315:H1200-H1214. [PMID: 30095973 PMCID: PMC6297824 DOI: 10.1152/ajpheart.00216.2018] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 07/13/2018] [Accepted: 07/25/2018] [Indexed: 12/22/2022]
Abstract
The hypothalamic paraventricular nucleus (PVN) is a unique and important brain region involved in the control of cardiovascular, neuroendocrine, and other physiological functions pertinent to homeostasis. The PVN is a major source of excitatory drive to the spinal sympathetic outflow via both direct and indirect projections. In this review, we discuss the role of the PVN in the regulation of sympathetic output in normal physiological conditions and in hypertension. In normal healthy animals, the PVN presympathetic neurons do not appear to have a major role in sustaining resting sympathetic vasomotor activity or in regulating sympathetic responses to short-term homeostatic challenges such as acute hypotension or hypoxia. Their role is, however, much more significant during longer-term challenges, such as sustained water deprivation, chronic intermittent hypoxia, and pregnancy. The PVN also appears to have a major role in generating the increased sympathetic vasomotor activity that is characteristic of multiple forms of hypertension. Recent studies in the spontaneously hypertensive rat model have shown that impaired inhibitory and enhanced excitatory synaptic inputs to PVN presympathetic neurons are the basis for the heightened sympathetic outflow in hypertension. We discuss the molecular mechanisms underlying the presynaptic and postsynaptic alterations in GABAergic and glutamatergic inputs to PVN presympathetic neurons in hypertension. In addition, we discuss the ability of exercise training to correct sympathetic hyperactivity by restoring blood-brain barrier integrity, reducing angiotensin II availability, and decreasing oxidative stress and inflammation in the PVN.
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Affiliation(s)
- Roger A Dampney
- Department of Physiology, University of Sydney , Sydney, New South Wales , Australia
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - De-Pei Li
- Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center , Houston, Texas
| | - Hui-Lin Pan
- Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center , Houston, Texas
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15
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Raquel HDA, Ferreira NZ, Lucchetti BFC, Falquetto B, Pinge-Filho P, Michelini LC, Martins-Pinge MC. The essential role of hypothalamic paraventricular nucleus nNOS in the modulation of autonomic control in exercised rats. Nitric Oxide 2018; 79:14-24. [DOI: 10.1016/j.niox.2018.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/24/2018] [Accepted: 07/02/2018] [Indexed: 12/31/2022]
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16
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Santos CR, Ruggeri A, Ceroni A, Michelini LC. Exercise training abrogates age-dependent loss of hypothalamic oxytocinergic circuitry and maintains high parasympathetic activity. J Neuroendocrinol 2018; 30:e12601. [PMID: 29656427 DOI: 10.1111/jne.12601] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 04/05/2018] [Indexed: 11/27/2022]
Abstract
Neuroanatomical studies associating neuronal tract tracing and immunohistochemistry identified reciprocal (ascending noradrenergic/descending oxytocinergic, OTergic) connections between brainstem cardiovascular nuclei and the paraventricular hypothalamic nucleus (PVN). Previous functional studies indicated that exercise training (T) augmented the expression/activity of OTergic pathway and improve the autonomic control of the heart. Knowing that ageing is associated with autonomic dysfunction and sinoaortic denervation blocked T-induced beneficial effects, we hypothesized that T was able to reduce age-dependent impairment by improving the afferent signaling to PVN and augmenting OTergic modulation of cardiovascular control. We evaluated the combined effects of T and age on plastic remodeling of ascending dopamine β-hydroxylase (DBH+) and descending OT+ pathways and correlated them with cardiovascular parameters. Male Wistar rats were submitted to T or kept sedentary for 8 weeks. After evaluating arterial pressure, heart rate (HR), their variabilities and spectral components in conscious rats at rest, brains were harvested to analyze the plastic remodeling of brain autonomic nuclei (immunofluorescence + confocal microscopy). The density of DBH+ neurons within the nucleus of solitary tract (NTS) and caudal ventrolateral medulla, the number of DBH+ terminals overlapping OT+ neurons in PVN preautonomic nuclei, as well as the density of OT+ neurons and their projections to NTS and dorsal motor nucleus of the vagus were markedly reduced in S rats during 8-weeks of inactivity In contrast, these effects were completely blocked by T and reversed to a large augmentation of DBH+ and OT+ densities in both cell bodies and terminals within autonomic nuclei and target areas. All plastic changes observed correlated positively with parasympathetic activity to the heart (HF-PI, but not with LF-PI) and negatively with resting HR. Data indicate that T, by increasing beneficial neuroplastic adaptive changes within brainstem-PVN reciprocal network, abrogates age-dependent deleterious remodeling and augments parasympathetic modulation of the heart, therefore improving autonomic function. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Carla R Santos
- Department of Physiology, Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
| | - Adriana Ruggeri
- Department of Physiology, Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
| | - Alexandre Ceroni
- Department of Physiology, Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
| | - Lisete C Michelini
- Department of Physiology, Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo/SP, Brazil
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17
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Buttler L, Jordão MT, Fragas MG, Ruggeri A, Ceroni A, Michelini LC. Maintenance of Blood-Brain Barrier Integrity in Hypertension: A Novel Benefit of Exercise Training for Autonomic Control. Front Physiol 2017; 8:1048. [PMID: 29311978 PMCID: PMC5733101 DOI: 10.3389/fphys.2017.01048] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/30/2017] [Indexed: 12/27/2022] Open
Abstract
The blood-brain barrier (BBB) is a complex multicellular structure acting as selective barrier controlling the transport of substances between these compartments. Accumulating evidence has shown that chronic hypertension is accompanied by BBB dysfunction, deficient local perfusion and plasma angiotensin II (Ang II) access into the parenchyma of brain areas related to autonomic circulatory control. Knowing that spontaneously hypertensive rats (SHR) exhibit deficient autonomic control and brain Ang II hyperactivity and that exercise training is highly effective in correcting both, we hypothesized that training, by reducing Ang II content, could improve BBB function within autonomic brain areas of the SHR. After confirming the absence of BBB lesion in the pre-hypertensive SHR, but marked fluorescein isothiocyanate dextran (FITC, 10 kD) leakage into the brain parenchyma of the hypothalamic paraventricular nucleus (PVN), nucleus of the solitary tract, and rostral ventrolateral medulla during the established phase of hypertension, adult SHR, and age-matched WKY were submitted to a treadmill training (T) or kept sedentary (S) for 8 weeks. The robust FITC leakage within autonomic areas of the SHR-S was largely reduced and almost normalized since the 2nd week of training (T2). BBB leakage reduction occurred simultaneously and showed strong correlations with both decreased LF/HF ratio to the heart and reduced vasomotor sympathetic activity (power spectral analysis), these effects preceding the appearance of resting bradycardia (T4) and partial pressure fall (T8). In other groups of SHR-T simultaneously infused with icv Ang II or saline (osmotic mini-pumps connected to a lateral ventricle cannula) we proved that decreased local availability of this peptide and reduced microglia activation (IBA1 staining) are crucial mechanisms conditioning the restoration of BBB integrity. Our data also revealed that Ang II-induced BBB lesion was faster within the PVN (T2), suggesting the prominent role of this nucleus in driven hypertension-induced deficits. These original set of data suggest that reduced local Ang II content (and decreased activation of its downstream pathways) is an essential and early-activated mechanism to maintain BBB integrity in trained SHR and uncovers a novel beneficial effect of exercise training to improve autonomic control even in the presence of hypertension.
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Affiliation(s)
- Leila Buttler
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Maria T Jordão
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Matheus G Fragas
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Adriana Ruggeri
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Alexandre Ceroni
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lisete C Michelini
- Department Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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18
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Silva SD, Jara ZP, Peres R, Lima LS, Scavone C, Montezano AC, Touyz RM, Casarini DE, Michelini LC. Temporal changes in cardiac oxidative stress, inflammation and remodeling induced by exercise in hypertension: Role for local angiotensin II reduction. PLoS One 2017; 12:e0189535. [PMID: 29232407 PMCID: PMC5726656 DOI: 10.1371/journal.pone.0189535] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 11/27/2017] [Indexed: 12/15/2022] Open
Abstract
Exercise training reduces renin-angiotensin system (RAS) activation, decreases plasma and tissue oxidative stress and inflammation in hypertension. However, the temporal nature of these phenomena in response to exercise is unknown. We sought to determine in spontaneously hypertensive rats (SHR) and age-matched WKY controls the weekly effects of training on blood pressure (BP), plasma and left ventricle (LV) Ang II and Ang-(1–7) content (HPLC), LV oxidative stress (DHE staining), gene and protein expression (qPCR and WB) of pro-inflammatory cytokines, antioxidant enzymes and their consequence on hypertension-induced cardiac remodeling. SHR and WKY were submitted to aerobic training (T) or maintained sedentary (S) for 8 weeks; measurements were made at weeks 0, 1, 2, 4 and 8. Hypertension-induced cardiac hypertrophy was accompanied by acute plasma Ang II increase with amplified responses during the late phase of LV hypertrophy. Similar pattern was observed for oxidative stress markers, TNF alpha and interleukin-1β, associated with cardiomyocytes’ diameter enlargement and collagen deposition. SHR-T exhibited prompt and marked decrease in LV Ang II content (T1vs T4 in WKY-T), normalized oxidative stress (T2), augmented antioxidant defense (T4) and reduced both collagen deposition and inflammatory profile (T8), without changing cardiomyocytes’ diameter and LV hypertrophy. These changes were accompanied by decreased plasma Ang II content (T2-T4) and reduced BP (T8). SHR-T and WKY-T showed parallel increases in LV and plasma Ang-(1–7) content. Our data indicate that early training-induced downregulation of LV ACE-AngII-AT1 receptor axis is a crucial mechanism to reduce oxidative/pro-inflammatory profile and improve antioxidant defense in SHR-T, showing in addition this effect precedes plasma RAS deactivation.
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Affiliation(s)
- Sebastião D. Silva
- Department of Physiology & Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
- Institute of Cardiovascular and Medical Sciences, BHF GCRC, University of Glasgow, Glasgow, United Kingdom
| | - Zaira P. Jara
- Department of Medicine, Federal University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Roseli Peres
- Department of Medicine, Federal University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Larissa S. Lima
- Department of Pharmacology, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Cristóforo Scavone
- Department of Pharmacology, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Augusto C. Montezano
- Institute of Cardiovascular and Medical Sciences, BHF GCRC, University of Glasgow, Glasgow, United Kingdom
| | - Rhian M. Touyz
- Institute of Cardiovascular and Medical Sciences, BHF GCRC, University of Glasgow, Glasgow, United Kingdom
| | - Dulce E. Casarini
- Department of Medicine, Federal University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Lisete C. Michelini
- Department of Physiology & Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
- * E-mail:
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19
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Experimental Evidences Supporting Training-Induced Benefits in Spontaneously Hypertensive Rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 999:287-306. [DOI: 10.1007/978-981-10-4307-9_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Ichige MHA, Santos CR, Jordão CP, Ceroni A, Negrão CE, Michelini LC. Exercise training preserves vagal preganglionic neurones and restores parasympathetic tonus in heart failure. J Physiol 2016; 594:6241-6254. [PMID: 27444212 PMCID: PMC5088253 DOI: 10.1113/jp272730] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/08/2016] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS Heart Failure (HF) is accompanied by reduced ventricular function, activation of compensatory neurohormonal mechanisms and marked autonomic dysfunction characterized by exaggerated sympathoexcitation and reduced parasympathetic activity. With 6 weeks of exercise training, HF-related loss of choline acetyltransferase (ChAT)-positive vagal preganglionic neurones is avoided, restoring the parasympathetic tonus to the heart, and the immunoreactivity of dopamine β-hydroxylase-positive premotor neurones that drive sympathetic outflow to the heart is reduced. Training-induced correction of autonomic dysfunction occurs even with the persistence of abnormal ventricular function. Strong positive correlation between improved parasympathetic tonus to the heart and increased ChAT immunoreactivity in vagal preganglionic neurones after training indicates this is a crucial mechanism to restore autonomic function in heart failure. ABSTRACT Exercise training is an efficient tool to attenuate sympathoexcitation, a hallmark of heart failure (HF). Although sympathetic modulation in HF is widely studied, information regarding parasympathetic control is lacking. We examined the combined effects of sympathetic and vagal tonus to the heart in sedentary (Sed) and exercise trained (ET) HF rats and the contribution of respective premotor and preganglionic neurones. Wistar rats submitted to coronary artery ligation or sham surgery were assigned to training or sedentary protocols for 6 weeks. After haemodynamic, autonomic tonus (atropine and atenolol i.v.) and ventricular function determinations, brains were collected for immunoreactivity assays (choline acetyltransferase, ChATir; dopamine β-hydroxylase, DBHir) and neuronal counting in the dorsal motor nucleus of vagus (DMV), nucleus ambiguus (NA) and rostroventrolateral medulla (RVLM). HF-Sed vs. SHAM-Sed exhibited decreased exercise capacity, reduced ejection fraction, increased left ventricle end diastolic pressure, smaller positive and negative dP/dt, decreased intrinsic heart rate (IHR), lower parasympathetic and higher sympathetic tonus, reduced preganglionic vagal neurones and ChATir in the DMV/NA, and increased RVLM DBHir. Training increased treadmill performance, normalized autonomic tonus and IHR, restored the number of DMV and NA neurones and corrected ChATir without affecting ventricular function. There were strong positive correlations between parasympathetic tonus and ChATir in NA and DMV. RVLM DBHir was also normalized by training, but there was no change in neurone number and no correlation with sympathetic tonus. Training-induced preservation of preganglionic vagal neurones is crucial to normalize parasympathetic activity and restore autonomic balance to the heart even in the persistence of cardiac dysfunction.
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Affiliation(s)
- Marcelo H A Ichige
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Carla R Santos
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Camila P Jordão
- Heart Institute, University of Sao Paulo, Medical School, Sao Paulo, SP, Brazil
| | - Alexandre Ceroni
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Carlos E Negrão
- Heart Institute, University of Sao Paulo, Medical School, Sao Paulo, SP, Brazil
- School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, SP, Brazil
| | - Lisete C Michelini
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of Sao Paulo, Sao Paulo, SP, Brazil.
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21
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De Melo VU, Saldanha RRM, Dos Santos CR, De Campos Cruz J, Lira VA, Santana-Filho VJ, Michelini LC. Ovarian Hormone Deprivation Reduces Oxytocin Expression in Paraventricular Nucleus Preautonomic Neurons and Correlates with Baroreflex Impairment in Rats. Front Physiol 2016; 7:461. [PMID: 27790154 PMCID: PMC5063006 DOI: 10.3389/fphys.2016.00461] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/26/2016] [Indexed: 11/24/2022] Open
Abstract
The prevalence of cardiovascular diseases including hypertension increases dramatically in women after menopause, however the mechanisms involved remain incompletely understood. Oxytocinergic (OTergic) neurons are largely present within the paraventricular nucleus of the hypothalamus (PVN). Several studies have shown that OTergic drive from PVN to brainstem increases baroreflex sensitivity and improves autonomic control of the circulation. Since preautonomic PVN neurons express different types of estrogen receptors, we hypothesize that ovarian hormone deprivation causes baroreflex impairment, autonomic imbalance and hypertension by negatively impacting OTergic drive and oxytocin levels in pre-autonomic neurons. Here, we assessed oxytocin gene and protein expression (qPCR and immunohistochemistry) within PVN subnuclei in sham-operated and ovariectomized Wistar rats. Conscious hemodynamic recordings were used to assess resting blood pressure and heart rate and the autonomic modulation of heart and vessels was estimated by power spectral analysis. We observed that the ovarian hormone deprivation in ovariectomized rats decreased baroreflex sensitivity, increased sympathetic and reduced vagal outflows to the heart and augmented the resting blood pressure. Of note, ovariectomized rats had reduced PVN oxytocin mRNA and protein expression in all pre-autonomic PVN subnuclei. Furthermore, reduced PVN oxytocin protein levels were positively correlated with decreased baroreflex sensitivity and negatively correlated with increased LF/HF ratio. These findings suggest that reduced oxytocin expression in OTergic neurons of the PVN contributes to the baroreflex dysfunction and autonomic dysregulation observed with ovarian hormone deprivation.
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Affiliation(s)
- Vitor U De Melo
- Department of Physiology, Federal University of SergipeSão Cristóvão, Brazil; Department of Health and Human Physiology, Obesity Research and Education Initiative, Fraternal Order of Eagles Diabetes Research Center, Abboud Cardiovascular Research Center, Pappajohn Biomedical Institute, University of IowaIowa, IA, USA
| | - Rayssa R M Saldanha
- Department of Physiology, Federal University of Sergipe São Cristóvão, Brazil
| | - Carla R Dos Santos
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | | | - Vitor A Lira
- Department of Health and Human Physiology, Obesity Research and Education Initiative, Fraternal Order of Eagles Diabetes Research Center, Abboud Cardiovascular Research Center, Pappajohn Biomedical Institute, University of Iowa Iowa, IA, USA
| | | | - Lisete C Michelini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
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Lopes PR, Moreira MCS, Marques SM, Pinto ISJ, Macedo LM, Silva CC, Freiria-Oliveira AH, Rebelo ACS, Reis AAS, Rosa DA, Ferreira-Neto ML, Castro CH, Pedrino GR. Association of exercise training and angiotensin-converting enzyme 2 activator improves baroreflex sensitivity of spontaneously hypertensive rats. ACTA ACUST UNITED AC 2016; 49:e5349. [PMID: 27533767 PMCID: PMC4988479 DOI: 10.1590/1414-431x20165349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 05/24/2016] [Indexed: 11/21/2022]
Abstract
The present study sought to determine cardiovascular effects of aerobic training associated with diminazene aceturate (DIZE), an activator of the angiotensin converting enzyme 2, in spontaneously hypertensive rats (SHRs). Male SHRs (280–350 g) were either subjected to exercise training or not (sedentary group). The trained group was subjected to 8 weeks of aerobic training on a treadmill (five times a week, lasting 60 min at an intensity of 50–60% of maximum aerobic speed). In the last 15 days of the experimental protocol, these groups were redistributed into four groups: i) sedentary SHRs with daily treatment of 1 mg/kg DIZE (S+D1); ii) trained SHRs with daily treatment of 1 mg/kg DIZE (T+D1); iii) sedentary SHRs with daily treatment of vehicle (S+V); and iv) trained SHRs with daily treatment of vehicle (T+V). After treatment, SHRs were anesthetized and subjected to artery and femoral vein cannulation prior to the implantation of ECG electrode. After 24 h, mean arterial pressure (MAP) and heart rate (HR) were recorded; the baroreflex sensitivity and the effect of double autonomic blockade (DAB) were evaluated in non-anesthetized SHRs. DIZE treatment improved baroreflex sensitivity in the T+D1 group as compared with the T+V and S+D1 groups. The intrinsic heart rate (IHR) and MAP were reduced in T+D1 group as compared with T+V and S+D1 groups. Hence, we conclude that the association of exercise training with DIZE treatment improved baroreflex function and cardiovascular regulation.
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Affiliation(s)
- P R Lopes
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - M C S Moreira
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - S M Marques
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - I S J Pinto
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - L M Macedo
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - C C Silva
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - A H Freiria-Oliveira
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - A C S Rebelo
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - A A S Reis
- Departamento de Bioquímica e Biologia Molecular, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - D A Rosa
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - M L Ferreira-Neto
- Faculdade de Educação Física, Universidade Federal de Uberlândia, Uberlândia, MG, Brasil
| | - C H Castro
- Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
| | - G R Pedrino
- Centro de Pesquisas em Neurociência e Fisiologia Cardiovascular, Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Goiânia, GO, Brasil
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Raquel HDA, Masson GS, Barna BF, Zanluqui NG, Pinge-Filho P, Michelini LC, Martins-Pinge MC. Swimming Training Modulates Nitric Oxide-Glutamate Interaction in the Rostral Ventrolateral Medulla in Normotensive Conscious Rats. Front Physiol 2016; 7:221. [PMID: 27378935 PMCID: PMC4904284 DOI: 10.3389/fphys.2016.00221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 05/27/2016] [Indexed: 12/20/2022] Open
Abstract
We evaluated the effects of swimming training on nitric oxide (NO) modulation to glutamate microinjection within the rostral ventrolateral medulla (RVLM) in conscious freely moving rats. Male Wistar rats were submitted to exercise training (Tr) by swimming or kept sedentary (Sed) for 4 weeks. After the last training session, RVLM guide cannulas and arterial/venous catheters were chronically implanted. Arterial pressure (AP), heart rate (HR), and baroreflex control of HR (loading/unloading of baroreceptors) were recorded in conscious rats at rest. Pressor response to L-glutamate in the RVLM was compared before and after blockade of local nitric oxide (NO) production. In other Tr and Sed groups, brain was harvested for gene (qRT-PCR) and protein (immunohistochemistry) expression of NO synthase (NOS) isoforms and measurement of NO content (nitrite assay) within the RVLM. Trained rats exhibited resting bradycardia (average reduction of 9%), increased baroreflex gain (Tr: −4.41 ± 0.5 vs. Sed: −2.42 ± 0.31 b/min/mmHg), and unchanged resting MAP. The pressor response to glutamate was smaller in the Tr group (32 ± 4 vs. 53 ± 2 mmHg, p < 0.05); this difference disappeared after RVLM pretreatment with carboxy-PTIO (NO scavenger), Nw-Propyl-L-Arginine and L-NAME (NOS inhibitors). eNOS immunoreactivity observed mainly in RVLM capillaries was higher in Tr, but eNOS gene expression was reduced. nNOS gene and protein expression was slightly reduced (−29 and −9%, respectively, P > 0.05). Also, RVLM NO levels were significantly reduced in Tr (−63% vs. Sed). After microinjection of a NO-donor, the attenuated pressor response of L-glutamate in Tr group was restored. Data indicate that swimming training by decreasing RVLM NO availability and glutamatergic neurotransmission to locally administered glutamate may contribute to decreased sympathetic activity in trained subjects.
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Affiliation(s)
- Hiviny de A Raquel
- Department of Physiological Sciences, Center of Biological Sciences, State University of Londrina Londrina, Brazil
| | - Gustavo S Masson
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Barbara Falquetto Barna
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Nágela G Zanluqui
- Department of Pathological Sciences, Center of Biological Sciences, State University of Londrina Londrina, Brazil
| | - Phileno Pinge-Filho
- Department of Pathological Sciences, Center of Biological Sciences, State University of Londrina Londrina, Brazil
| | - Lisete C Michelini
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo São Paulo, Brazil
| | - Marli C Martins-Pinge
- Department of Physiological Sciences, Center of Biological Sciences, State University of Londrina Londrina, Brazil
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Early Training-Induced Reduction of Angiotensinogen in Autonomic Areas-The Main Effect of Exercise on Brain Renin-Angiotensin System in Hypertensive Rats. PLoS One 2015; 10:e0137395. [PMID: 26372108 PMCID: PMC4570767 DOI: 10.1371/journal.pone.0137395] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 08/17/2015] [Indexed: 02/03/2023] Open
Abstract
Background Exercise training (T) blunts functional deficits and renin-angiotensin system (RAS) hyperactivity in hypertensive individuals. There is no information on T-induced temporal changes of brain RAS. We evaluate now the simultaneous effects of T on functional responses and time course changes in the expression/activity of brain RAS components in autonomic cardiovascular-controlling areas. Methods and Results Spontaneously hypertensive rats (SHR) and age-matched normotensive controls (WKY) were trained for 0, 1, 2, 4, 8 and 12 weeks. Sedentary (S) groups served as time-controls. After arterial pressure (AP) and heart rate (HR) recordings at rest, fresh and fixed brains were harvested for qPCR and immunofluorescence assays. SHR-S vs. WKY-S exhibited higher mean AP (MAP) and HR, increased pressure variability and sympathetic activity, elevated AT1 receptor (AT1) expression in nucleus tractus solitarii (NTS) and higher Mas receptor expression in the rostroventrolateral medulla (RVLM). In SHR, T promptly (T2 on) reduced sympathetic variability to heart/vessels and largely decreased angiotensinogen expression in the paraventricular hypothalamic nucleus (PVN) and NTS, with a late RVLM reduction (T4). AT1 expression was only reduced at T12 (PVN and NTS) with transient, not maintained Mas receptor changes in PVN and RVLM. These responses were accompanied by baseline MAP and HR reduction in the SHR-T (from T4 on). In the SHR group, PVN angiotensinogen expression correlated positively with sympathetic activity, resting MAP and HR. In WKY-T, a precocious (T2-T12) RVLM AT1 decrease preceded the appearance of resting bradycardia (from T8 on). Conclusions Early and maintained reduction of angiotensinogen content in autonomic areas of the SHR is the most prominent effect of training on brain RAS. Down-regulation of PVN RAS expression is an essential factor to drive cardiovascular benefits in SHR-T, while resting bradycardia in WKY-T is correlated to RVLM AT1 reduction.
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Masson GS, Nair AR, Silva Soares PP, Michelini LC, Francis J. Aerobic training normalizes autonomic dysfunction, HMGB1 content, microglia activation and inflammation in hypothalamic paraventricular nucleus of SHR. Am J Physiol Heart Circ Physiol 2015; 309:H1115-22. [PMID: 26254332 DOI: 10.1152/ajpheart.00349.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 07/25/2015] [Indexed: 11/22/2022]
Abstract
Exercise training (ExT) is recommended to treat hypertension along with pharmaceutical antihypertensive therapies. Effects of ExT in hypothalamic content of high mobility box 1 (HMGB1) and microglial activation remain unknown. We examined whether ExT would decrease autonomic and cardiovascular abnormalities in spontaneously hypertensive rats (SHR), and whether these effects were associated with decreased HMGB1 content, microglial activation, and inflammation in the hypothalamic paraventricular nucleus (PVN). Normotensive Wistar-Kyoto (WKY) rats and SHR underwent moderate-intensity ExT for 2 wk. After ExT, cardiovascular (heart rate and arterial pressure) and autonomic parameters (arterial pressure and heart rate variability, peripheral sympathetic activity, cardiac vagal activity, and baroreflex function) were measured in conscious and freely-moving rats through chronic arterial and venous catheterization. Cerebrospinal fluid, plasma, and brain were collected for molecular and immunohistochemistry analyses of the PVN. In addition to reduced heart rate variability, decreased vagal cardiac activity and increased mean arterial pressure, heart rate, arterial pressure variability, cardiac, and vasomotor sympathetic activity, SHR had higher HMGB1 protein expression, IκB-α phosphorylation, TNF-α and IL-6 protein expression, and microglia activation in the PVN. These changes were accompanied by higher plasma and cerebrospinal fluid levels of HMGB1. The ExT + SHR group had decreased expression of HMGB1, CXCR4, SDF-1, and phosphorylation of p42/44 and IκB-α. ExT reduced microglial activation and proinflammatory cytokines content in the PVN, and improved autonomic control as well. Data suggest that training-induced downregulation of activated HMGB1/CXCR4/microglia/proinflammatory cytokines axis in the PVN of SHR is a prompt neural adaptation to counterbalance the deleterious effects of inflammation on autonomic control.
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Affiliation(s)
- Gustavo Santos Masson
- Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana; Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil; and
| | - Anand R Nair
- Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | | | - Lisete Compagno Michelini
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil; and
| | - Joseph Francis
- Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana;
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Michelini LC, O'Leary DS, Raven PB, Nóbrega ACL. Neural control of circulation and exercise: a translational approach disclosing interactions between central command, arterial baroreflex, and muscle metaboreflex. Am J Physiol Heart Circ Physiol 2015; 309:H381-92. [PMID: 26024683 PMCID: PMC4631530 DOI: 10.1152/ajpheart.00077.2015] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 05/18/2015] [Indexed: 01/13/2023]
Abstract
The last 100 years witnessed a rapid and progressive development of the body of knowledge concerning the neural control of the cardiovascular system in health and disease. The understanding of the complexity and the relevance of the neuroregulatory system continues to evolve and as a result raises new questions. The purpose of this review is to articulate results from studies involving experimental models in animals as well as in humans concerning the interaction between the neural mechanisms mediating the hemodynamic responses during exercise. The review describes the arterial baroreflex, the pivotal mechanism controlling mean arterial blood pressure and its fluctuations along with the two main activation mechanisms to exercise: central command (parallel activation of central somatomotor and autonomic descending pathways) and the muscle metaboreflex, the metabolic component of exercise pressor reflex (feedback from ergoreceptors within contracting skeletal muscles). In addition, the role of the cardiopulmonary baroreceptors in modulating the resetting of arterial baroreflex is identified, and the mechanisms in the central nervous system involved with the resetting of baroreflex function during dynamic exercise are also described. Approaching a very relevant clinical condition, the review also presents the concept that the impaired arterial baroreflex function is an integral component of the metaboreflex-mediated exaggerated sympathetic tone in subjects with heart failure. This increased sympathetic activity has a major role in causing the depressed ventricular function observed during submaximal dynamic exercise in these patients. The potential contribution of a metaboreflex arising from respiratory muscles is also considered.
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Affiliation(s)
- Lisete C Michelini
- Department of Physiology and Biophysics, Biomedical Sciences Institute, University of São Paulo, São Paulo, Brazil
| | - Donal S O'Leary
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | - Peter B Raven
- Department of Integrative Physiology, University of North Texas Health Science Center, Fort Worth, Texas; and
| | - Antonio C L Nóbrega
- Department of Physiology and Pharmacology, Fluminense Federal University, Niteroi, Brazil
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Sladek CD, Michelini LC, Stachenfeld NS, Stern JE, Urban JH. Endocrine‐Autonomic Linkages. Compr Physiol 2015; 5:1281-323. [DOI: 10.1002/cphy.c140028] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Abstract
Because of resetting, a role for baroreflexes in long-term control of arterial pressure has been commonly dismissed in the past. However, in recent years, this perspective has changed. Novel approaches for determining chronic neurohormonal and cardiovascular responses to natural variations in baroreceptor activity and to electrical stimulation of the carotid baroreflex indicate incomplete resetting and sustained responses that lead to long-term alterations in sympathetic activity and arterial pressure.
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Affiliation(s)
- Thomas E Lohmeier
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - Radu Iliescu
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi; and Department of Physiology, University of Medicine and Pharmacology, Gr. T. Popa, Iasi, Romania
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Time-dependent effects of training on cardiovascular control in spontaneously hypertensive rats: role for brain oxidative stress and inflammation and baroreflex sensitivity. PLoS One 2014; 9:e94927. [PMID: 24788542 PMCID: PMC4006803 DOI: 10.1371/journal.pone.0094927] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 03/20/2014] [Indexed: 12/26/2022] Open
Abstract
Baroreflex dysfunction, oxidative stress and inflammation, important hallmarks of hypertension, are attenuated by exercise training. In this study, we investigated the relationships and time-course changes of cardiovascular parameters, pro-inflammatory cytokines and pro-oxidant profiles within the hypothalamic paraventricular nucleus of the spontaneously hypertensive rats (SHR). Basal values and variability of arterial pressure and heart rate and baroreflex sensitivity were measured in trained (T, low-intensity treadmill training) and sedentary (S) SHR at weeks 0, 1, 2, 4 and 8. Paraventricular nucleus was used to determine reactive oxygen species (dihydroethidium oxidation products, HPLC), NADPH oxidase subunits and pro-inflammatory cytokines expression (Real time PCR), p38 MAPK and ERK1/2 expression (Western blotting), NF-κB content (electrophoretic mobility shift assay) and cytokines immunofluorescence. SHR-S vs. WKY-S (Wistar Kyoto rats as time control) showed increased mean arterial pressure (172±3 mmHg), pressure variability and heart rate (358±7 b/min), decreased baroreflex sensitivity and heart rate variability, increased p47phox and reactive oxygen species production, elevated NF-κB activity and increased TNF-α and IL-6 expression within the paraventricular nucleus of hypothalamus. Two weeks of training reversed all hypothalamic changes, reduced ERK1/2 phosphorylation and normalized baroreflex sensitivity (4.04±0.31 vs. 2.31±0.19 b/min/mmHg in SHR-S). These responses were followed by increased vagal component of heart rate variability (1.9-fold) and resting bradycardia (−13%) at the 4th week, and, by reduced vasomotor component of pressure variability (−28%) and decreased mean arterial pressure (−7%) only at the 8th week of training. Our findings indicate that independent of the high pressure levels in SHR, training promptly restores baroreflex function by disrupting the positive feedback between high oxidative stress and increased pro-inflammatory cytokines secretion within the hypothalamic paraventricular nucleus. These early adaptive responses precede the occurrence of training-induced resting bradycardia and blood pressure fall.
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Andresen MC, Fawley JA, Hofmann ME. Peptide and lipid modulation of glutamatergic afferent synaptic transmission in the solitary tract nucleus. Front Neurosci 2013; 6:191. [PMID: 23335875 PMCID: PMC3541483 DOI: 10.3389/fnins.2012.00191] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 12/17/2012] [Indexed: 12/21/2022] Open
Abstract
The brainstem nucleus of the solitary tract (NTS) holds the first central neurons in major homeostatic reflex pathways. These homeostatic reflexes regulate and coordinate multiple organ systems from gastrointestinal to cardiopulmonary functions. The core of many of these pathways arise from cranial visceral afferent neurons that enter the brain as the solitary tract (ST) with more than two-thirds arising from the gastrointestinal system. About one quarter of ST afferents have myelinated axons but the majority are classed as unmyelinated C-fibers. All ST afferents release the fast neurotransmitter glutamate with remarkably similar, high-probability release characteristics. Second order NTS neurons receive surprisingly limited primary afferent information with one or two individual inputs converging on single second order NTS neurons. A- and C-fiber afferents never mix at NTS second order neurons. Many transmitters modify the basic glutamatergic excitatory postsynaptic current often by reducing glutamate release or interrupting terminal depolarization. Thus, a distinguishing feature of ST transmission is presynaptic expression of G-protein coupled receptors for peptides common to peripheral or forebrain (e.g., hypothalamus) neuron sources. Presynaptic receptors for angiotensin (AT1), vasopressin (V1a), oxytocin, opioid (MOR), ghrelin (GHSR1), and cholecystokinin differentially control glutamate release on particular subsets of neurons with most other ST afferents unaffected. Lastly, lipid-like signals are transduced by two key ST presynaptic receptors, the transient receptor potential vanilloid type 1 and the cannabinoid receptor that oppositely control glutamate release. Increasing evidence suggests that peripheral nervous signaling mechanisms are repurposed at central terminals to control excitation and are major sites of signal integration of peripheral and central inputs particularly from the hypothalamus.
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Affiliation(s)
- Michael C Andresen
- Department of Physiology and Pharmacology, Oregon Health and Science University Portland, OR, USA
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Cruz JC, Cavalleri MT, Ceroni A, Michelini LC. Peripheral chemoreceptors mediate training-induced plasticity in paraventricular nucleus pre-autonomic oxytocinergic neurons. Exp Physiol 2012; 98:386-96. [DOI: 10.1113/expphysiol.2012.065888] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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