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Ishii K, Machino T, Hatori Y, Gwak J, Izaki T, Komine H. Differential relationship between decreased muscle oxygenation and blood pressure recovery during supraventricular and ventricular tachycardia. Sci Rep 2023; 13:15886. [PMID: 37741868 PMCID: PMC10517960 DOI: 10.1038/s41598-023-42908-2] [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: 06/05/2023] [Accepted: 09/15/2023] [Indexed: 09/25/2023] Open
Abstract
Vasoconstriction during tachyarrhythmia contributes to maintenance of arterial pressure (AP) by decreasing peripheral blood flow. This cross-sectional observational study aimed to ascertain whether the relationship between peripheral blood flow and AP recovery occurs during both paroxysmal supraventricular (PSVT, n = 19) and ventricular tachycardias (VT, n = 17). Peripheral blood flow was evaluated using forearm tissue oxygen index (TOI), and mean AP (MAP) was measured using a catheter inserted in the brachial or femoral artery during an electrophysiological study. PSVT and VT rapidly decreased MAP with a comparable heart rate (P = 0.194). MAP recovered to the baseline level at 40 s from PSVT onset, but not VT. The forearm TOI decreased during both tachyarrhythmias (P ≤ 0.029). The TOI response was correlated with MAPrecovery (i.e., MAP recovery from the initial rapid decrease) at 20-60 s from PSVT onset (r = -- 0.652 to - 0.814, P ≤ 0.0298); however, this association was not observed during VT. These findings persisted even after excluding patients who had taken vasoactive drugs. Thus, restricting peripheral blood flow was associated with MAP recovery during PSVT, but not VT. This indicates that AP recovery depends on the type of tachyarrhythmia: different cardiac output and/or vasoconstriction ability during tachyarrhythmia.
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Affiliation(s)
- Kei Ishii
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Takeshi Machino
- Department of Cardiology, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yasuhiro Hatori
- Research Institute of Electrical Communication, Tohoku University, Sendai, Miyagi, Japan
| | - Jongseong Gwak
- Department of Computer Science, Takushoku University, Hachioji, Tokyo, Japan
| | - Tsubasa Izaki
- School of Economics and Management, Kochi University of Technology, Kochi, Kochi, Japan
| | - Hidehiko Komine
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan.
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2
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Elia A, Fossati S. Autonomic nervous system and cardiac neuro-signaling pathway modulation in cardiovascular disorders and Alzheimer's disease. Front Physiol 2023; 14:1060666. [PMID: 36798942 PMCID: PMC9926972 DOI: 10.3389/fphys.2023.1060666] [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: 10/03/2022] [Accepted: 01/19/2023] [Indexed: 01/31/2023] Open
Abstract
The heart is a functional syncytium controlled by a delicate and sophisticated balance ensured by the tight coordination of its several cell subpopulations. Accordingly, cardiomyocytes together with the surrounding microenvironment participate in the heart tissue homeostasis. In the right atrium, the sinoatrial nodal cells regulate the cardiac impulse propagation through cardiomyocytes, thus ensuring the maintenance of the electric network in the heart tissue. Notably, the central nervous system (CNS) modulates the cardiac rhythm through the two limbs of the autonomic nervous system (ANS): the parasympathetic and sympathetic compartments. The autonomic nervous system exerts non-voluntary effects on different peripheral organs. The main neuromodulator of the Sympathetic Nervous System (SNS) is norepinephrine, while the principal neurotransmitter of the Parasympathetic Nervous System (PNS) is acetylcholine. Through these two main neurohormones, the ANS can gradually regulate cardiac, vascular, visceral, and glandular functions by turning on one of its two branches (adrenergic and/or cholinergic), which exert opposite effects on targeted organs. Besides these neuromodulators, the cardiac nervous system is ruled by specific neuropeptides (neurotrophic factors) that help to preserve innervation homeostasis through the myocardial layers (from epicardium to endocardium). Interestingly, the dysregulation of this neuro-signaling pathway may expose the cardiac tissue to severe disorders of different etiology and nature. Specifically, a maladaptive remodeling of the cardiac nervous system may culminate in a progressive loss of neurotrophins, thus leading to severe myocardial denervation, as observed in different cardiometabolic and neurodegenerative diseases (myocardial infarction, heart failure, Alzheimer's disease). This review analyzes the current knowledge on the pathophysiological processes involved in cardiac nervous system impairment from the perspectives of both cardiac disorders and a widely diffused and devastating neurodegenerative disorder, Alzheimer's disease, proposing a relationship between neurodegeneration, loss of neurotrophic factors, and cardiac nervous system impairment. This overview is conducive to a more comprehensive understanding of the process of cardiac neuro-signaling dysfunction, while bringing to light potential therapeutic scenarios to correct or delay the adverse cardiovascular remodeling, thus improving the cardiac prognosis and quality of life in patients with heart or neurodegenerative disorders.
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Goulart MT, Busnardo C, Belém-Filho IJA, Benini R, Fassini A, Crestani CC, Godoy AC, Correa FMA, Alves FHF. NMDA receptors in the insular cortex modulate cardiovascular and autonomic but not neuroendocrine responses to restraint stress in rats. Prog Neuropsychopharmacol Biol Psychiatry 2022; 119:110598. [PMID: 35798175 DOI: 10.1016/j.pnpbp.2022.110598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 06/27/2022] [Accepted: 06/30/2022] [Indexed: 11/26/2022]
Abstract
The insular cortex (IC) is a brain structure involved in physiological and behavioural responses during stressful events. However, the local neurochemical mechanisms involved in control of stress responses by the IC are poorly understood. Thus, this study aimed to investigate the involvement of glutamatergic neurotransmission within the IC in cardiovascular, autonomic and neuroendocrine responses to an acute session of restraint stress. For this, the selective NMDA glutamate receptor antagonist LY235959 (1 nmol/100 nL) or the selective non-NMDA glutamate receptor antagonist NBQX (1 nmol/100 nL) were microinjected into the IC 10 min before the onset of the 60 min session of restraint stress. We observed that the antagonism of NMDA receptors within the IC enhanced the restraint-evoked increase in arterial pressure and heart rate, while blockade of non-NMDA receptors did not affect these cardiovascular responses. Spontaneous baroreflex analysis demonstrated that microinjection of LY235959 into the IC decreased baroreflex activity during restraint stress. The decrease in tail skin temperature during restraint stress was shifted to an increase in animals treated with the NMDA receptor antagonist. Nevertheless, the blockade of either NMDA or non-NMDA glutamate receptors within the IC did not affect the increase in circulating corticosterone levels during restraint stress. Overall, our findings provide evidence that IC glutamatergic neurotransmission, acting via local NMDA receptors, plays a prominent role in the control of autonomic and cardiovascular responses to restraint stress, but without affecting neuroendocrine adjustments.
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Affiliation(s)
- Melissa T Goulart
- Department of Health Sciences, Faculty of Medicine - Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Cristiane Busnardo
- Departments of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ivaldo J A Belém-Filho
- Departments of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Ricardo Benini
- Department of Drugs and Pharmaceutics, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Aline Fassini
- Departments of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Carlos C Crestani
- Department of Drugs and Pharmaceutics, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil
| | - Ana C Godoy
- Department of Health Sciences, Faculty of Medicine - Federal University of Lavras, Lavras, Minas Gerais, Brazil
| | - Fernando M A Correa
- Departments of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Fernando H F Alves
- Department of Health Sciences, Faculty of Medicine - Federal University of Lavras, Lavras, Minas Gerais, Brazil.
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4
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Belém-Filho IJA, Brasil TFS, Fortaleza EAT, Antunes-Rodrigues J, Corrêa FMA. A functional selective effect of oxytocin secreted under restraint stress in rats. Eur J Pharmacol 2021; 904:174182. [PMID: 34004212 DOI: 10.1016/j.ejphar.2021.174182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 04/22/2021] [Accepted: 05/12/2021] [Indexed: 12/24/2022]
Abstract
Restraint stress (RS) is an unavoidable stress model that triggers activation of the autonomic nervous system, endocrine activity, and behavioral changes in rodents. Furthermore, RS induces secretion of oxytocin into the bloodstream, indicating a possible physiological role in the stress response in this model. The presence of oxytocin receptors in vessels and heart favors this possible idea. However, the role of oxytocin secreted in RS and effects on the cardiovascular system are still unclear. The aim of this study was to analyze the influence of oxytocin on cardiovascular effects during RS sessions. Rats were subjected to pharmacological (blockade of either oxytocin, vasopressin, or muscarinic receptors) or surgical (hypophysectomy or sinoaortic denervation) approaches to study the functional role of oxytocin and its receptor during RS. Plasma levels of oxytocin and vasopressin were measured after RS. RS increased arterial pressure, heart rate, and plasma oxytocin content, but not vasopressin. Treatment with atosiban (a Gi biased agonist) inhibited restraint-evoked tachycardia without affecting blood pressure. However, this effect was no longer observed after sinoaortic denervation, homatropine (M2 muscarinic antagonist) treatment or hypophysectomy, indicating that parasympathetic activation mediated by oxytocin secreted to the periphery is responsible for blocking the increase in tachycardic responses observed in the atosiban-treated group. Corroborating this, L-368,899 (oxytocin antagonist) treatment showed an opposite effect to atosiban, increasing tachycardic responses to restraint. Thus, this provides evidence that oxytocin secreted to the periphery attenuates tachycardic responses evoked by restraint via increased parasympathetic activity, promoting cardioprotection by reducing the stress-evoked heart rate increase.
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Affiliation(s)
| | - Taíz Francine Silva Brasil
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | | | - José Antunes-Rodrigues
- Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Fernando Morgan Aguiar Corrêa
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil
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Armelin VA, Braga VHDS, Teixeira MT, Guagnoni IN, Wang T, Florindo LH. The nonpharmacological sequence method provides a reliable evaluation of baroreflex sensitivity in fish. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:348-358. [PMID: 33503334 DOI: 10.1002/jez.2448] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/22/2020] [Accepted: 01/08/2021] [Indexed: 11/10/2022]
Abstract
The most commonly used technique to study the barostatic regulation of blood pressure in ectothermic vertebrates consists of determining the heart rate response to pharmacological manipulations of blood pressure, the so-called "Oxford method." Although well established, the Oxford method has some important limitations, such as induction of hypervolemia in small animals and undesired effects of vasoactive drugs on central and peripheral baroreflex components. As an alternative, the sequence method, which consists in the computerized evaluation of naturally-occurring baroreflex adjustments of heart rate without the need for pharmacological administrations, was developed to study baroreflexes. In the present study, we compare this sequence method with the Oxford technique in two teleost species with different life styles, and we assess the optimal software configuration for the employment of the sequence method in fish. Calculation of baroreflex gain through the sequence method was adequate and reliable when the software was configured to search for baroreflex sequences with a minimum length of three cardiac cycles with a delay of one cardiac cycle between fluctuations in mean ventral aortic blood pressure and reflex changes in pulse interval. When properly configured, the sequence and the Oxford methods yielded similar determinations of the baroreflex gain in fish.
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Affiliation(s)
- Vinicius A Armelin
- Department of Physiology, University of São Paulo (USP), São Paulo, SP, Brazil.,Department of Zoology and Botany, São Paulo State University (UNESP), São José do Rio Preto, SP, Brazil.,National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil
| | - Victor H da Silva Braga
- Department of Zoology and Botany, São Paulo State University (UNESP), São José do Rio Preto, SP, Brazil.,National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil
| | - Mariana T Teixeira
- Department of Zoology and Botany, São Paulo State University (UNESP), São José do Rio Preto, SP, Brazil.,National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil
| | - Igor N Guagnoni
- Department of Zoology and Botany, São Paulo State University (UNESP), São José do Rio Preto, SP, Brazil.,National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil
| | - Tobias Wang
- National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil.,Section for Zoophysiology, Department of Bioscience, Aarhus University (AU), Aarhus, Denmark
| | - Luiz H Florindo
- Department of Zoology and Botany, São Paulo State University (UNESP), São José do Rio Preto, SP, Brazil.,National Institute of Science and Technology in Comparative Physiology (INCT-FAPESP/CNPq), Rio Claro, SP, Brazil.,Aquaculture Center (CAUNESP), São Paulo State University (UNESP), Jaboticabal, SP, Brazil
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6
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Reis-Silva LL, Barretto-de-Souza L, Benini R, Crestani CC. CRF 1 and CRF 2 receptors in the lateral hypothalamus differently modulate the baroreflex function in unanesthetized rats. Brain Res 2020; 1751:147195. [PMID: 33159974 DOI: 10.1016/j.brainres.2020.147195] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/24/2020] [Accepted: 10/30/2020] [Indexed: 10/23/2022]
Abstract
The lateral hypothalamus (LH) is a diencephalic structure that has been considered part of the central circuitry regulating the baroreflex function. However, the local neurochemical mechanisms involved in baroreflex control by this hypothalamic area are poorly understood. Therefore, in the present study we investigated the role of corticotropin-releasing factor (CRF) neurotransmission within the LH acting via local CRF1 and CRF2 receptors in cardiac baroreflex responses in unanesthetized rats. For this, the baroreflex activity was assessed using two approaches: i) the pharmacological approach via intravenous infusion of vasoactive agents, and ii) the sequence analysis technique that evaluates reflex responses during spontaneous arterial pressure variations. The sequence analysis technique indicated that LH treatment with the selective CRF1 receptor antagonist CP376395 decreased the baroreflex effectiveness index, whereas the selective CRF2 receptor antagonist antisauvagine-30 increased the reflex shortening of pulse interval during spontaneous arterial pressure decreases. However, the pharmacological approach did not indicate effect of the bilateral microinjection of either CP376395 or antisauvagine-30 into the LH in the tachycardia evoked by blood pressure decrease or the reflex bradycardia caused by blood pressure increase. Overall, these findings indicate that CRF neurotransmission within the LH controls baroreflex function during a narrow range of physiological arterial pressure variations. Besides, results provide evidence that CRF1 and CRF2 receptors in the LH oppositely modulate the spontaneous baroreflex activity through different mechanisms.
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Affiliation(s)
- Lilian L Reis-Silva
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, SP, Brazil; Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
| | - Lucas Barretto-de-Souza
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, SP, Brazil; Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
| | - Ricardo Benini
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, SP, Brazil; Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil
| | - Carlos C Crestani
- Laboratory of Pharmacology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, SP, Brazil; Joint UFSCar-UNESP Graduate Program in Physiological Sciences, São Carlos, SP, Brazil.
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7
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Gu F, Randall EB, Whitesall S, Converso-Baran K, Carlson BE, Fink GD, Michele DE, Beard DA. Potential role of intermittent functioning of baroreflexes in the etiology of hypertension in spontaneously hypertensive rats. JCI Insight 2020; 5:139789. [PMID: 33004690 PMCID: PMC7566704 DOI: 10.1172/jci.insight.139789] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/31/2020] [Indexed: 12/24/2022] Open
Abstract
The spontaneously hypertensive rat (SHR) is a genetic model of primary hypertension with an etiology that includes sympathetic overdrive. To elucidate the neurogenic mechanisms underlying the pathophysiology of this model, we analyzed the dynamic baroreflex response to spontaneous fluctuations in arterial pressure in conscious SHRs, as well as in the Wistar-Kyoto (WKY), the Dahl salt-sensitive, the Dahl salt-resistant, and the Sprague-Dawley rat. Observations revealed the existence of long intermittent periods (lasting up to several minutes) of engagement and disengagement of baroreflex control of heart rate. Analysis of these intermittent periods revealed a predictive relationship between increased mean arterial pressure and progressive baroreflex disengagement that was present in the SHR and WKY strains but absent in others. This relationship yielded the hypothesis that a lower proportion of engagement versus disengagement of the baroreflex in SHR compared with WKY contributes to the hypertension (or increased blood pressure) in SHR compared with WKY. Results of experiments using sinoaortic baroreceptor denervation were consistent with the hypothesis that dysfunction of the baroreflex contributes to the etiology of hypertension in the SHR. Thus, this study provides experimental evidence for the roles of the baroreflex in long-term arterial pressure regulation and in the etiology of primary hypertension in this animal model. Baroreflex dysfunction contributes to the etiology of hypertension in a genetic model of primary hypertension.
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Affiliation(s)
- Feng Gu
- Department of Vascular Surgery, Second Xiangya Hospital, Central South University, Changsha, China.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - E Benjamin Randall
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Steven Whitesall
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kimber Converso-Baran
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Brian E Carlson
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Gregory D Fink
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
| | - Daniel A Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
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Madden KM, Feldman B, Meneilly GS. Baroreflex function and postprandial hypotension in older adults. Clin Auton Res 2020; 31:273-280. [PMID: 32062813 DOI: 10.1007/s10286-020-00671-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/07/2020] [Indexed: 10/25/2022]
Abstract
PURPOSE Postprandial hypotension (PPH) is a common but poorly understood etiology for fainting in older adults. One potential mechanism is age-related baroreflex dysfunction. We examined baroreflex function in older adults with PPH and without PPH (noPPH) during a standardized meal test. METHODS 57 adults (age ≥ 65; 24 PPH, 33 noPPH, mean age 77.9 ± 0.9 years, 54% female) were recruited and had meal tests performed. The baroreflex effectiveness index (BEI, %) and baroreflex sensitivity (BRS, ms/mm Hg) were calculated using the sequence method. RESULTS Baseline BEI (22 ± 2 versus 23 ± 2 percent, t = - 0.411, p = 0.682) and BRS (14.1 ± 2.4 versus 13.8 ± 2.5 ms/mm of Hg, t = - 0.084, p = 0.933) were similar in PPH and noPPH subjects. During the meal test PPH subjects showed significantly lower BEI as compared to noPPH subjects (time × PPH, F = 2.791, p = 0.042), while there was no difference in the postprandial change in BRS (time, F = 0.618, p = 0.605). CONCLUSION Patients with PPH demonstrated an acute postprandial decrease in baroreflex effectiveness during meal testing as compared with normal subjects, suggesting a potential contributing mechanism for this condition.
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Affiliation(s)
- Kenneth M Madden
- Gerontology and Diabetes Research Laboratory, Division of Geriatric Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada. .,Centre for Hip Health and Mobility, University of British Columbia, Vancouver, BC, Canada. .,Allan M. McGavin Chair in Geriatric Medicine, Room 7185, Gordon and Leslie Diamond Health Care Centre, 2775 Laurel St., Vancouver, BC, V5Z 1M9, Canada.
| | - Boris Feldman
- Gerontology and Diabetes Research Laboratory, Division of Geriatric Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Graydon S Meneilly
- Gerontology and Diabetes Research Laboratory, Division of Geriatric Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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TLR4 participates in sympathetic hyperactivity Post-MI in the PVN by regulating NF-κB pathway and ROS production. Redox Biol 2019; 24:101186. [PMID: 30978539 PMCID: PMC6460304 DOI: 10.1016/j.redox.2019.101186] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 03/14/2019] [Accepted: 03/28/2019] [Indexed: 01/01/2023] Open
Abstract
Sympathetic nerve hyperactivity is a primary reason for fatal ventricular arrhythmias (VAs) following myocardial infarction (MI). Pro-inflammatory cytokines produced in the paraventricular nucleus (PVN) post-MI are associated with sympathetic overexcitation; however, the precise mechanism needs further investigation. Our aim was to explore the mechanism of toll-like receptor 4 (TLR4) and its downstream molecular pathway in mediating sympathetic activity post-MI within the PVN. A rat MI model was developed via left anterior descending coronary artery ligation. TLR4 was primarily localized in microglia and increased markedly within the PVN at 3 days in MI rats. Sympathoexcitation also increased, as indicated by high levels of renal sympathetic nerve activity (RSNA) and norepinephrine (NE) concentration. TLR4 knockdown via shRNA microinjection to the PVN resulted in decreased activation of Fos protein (+) neurons in the PVN and peripheral sympathetic nerve activity. TLR4 knockdown also exhibited a lower arrhythmia score following programmed electrical stimulation than those treated with MI surgery only, indicating that the knockdown of TLR4 decreased the incidence of malignant ventricular arrhythmias following MI. LPS-induced inflammatory response was analyzed to explore the underlying mechanism of TLR4 in sympathetic hyperactivity. High levels of NF-κB protein, the pro-inflammatory cytokines IL-1β and TNF-α, and ROS production were observed in the LPS group. PVN-targeted injection of the NF-κB inhibitor PDTC attenuated NF-κB expression and sympathetic activity. Taken together, the results suggested that knockdown of microglial TLR4 within the PVN decreased sympathetic hyperactivity and subsequent VAs post-MI. The downstream NF-κB pathway and ROS production participated in the process. Interventions targeting TLR4 signaling in the PVN may be a novel approach to ameliorate the incidence of VAs post-MI.
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10
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Silva LEV, Dias DPM, da Silva CAA, Salgado HC, Fazan R. Revisiting the Sequence Method for Baroreflex Analysis. Front Neurosci 2019; 13:17. [PMID: 30728765 PMCID: PMC6352748 DOI: 10.3389/fnins.2019.00017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/09/2019] [Indexed: 11/22/2022] Open
Abstract
The sequence method is an important approach to assess the baroreflex function, mainly because it is based on the spontaneous fluctuations of beat-by-beat arterial pressure (for example, systolic arterial pressure or SAP) and pulse interval (PI). However, some studies revealed that the baroreflex effectiveness index (BEI), calculated through the sequence method, shows an intriguing oscillatory pattern as function of the delay between SAP and PI. It has been hypothesized that this pattern is related to the respiratory influence on SAP and/or PI variability, limiting the SAP ramps to 3 or 4 beats of length. In this study, this hypothesis was tested by assessing the sequence method using raw (original) and filtered series. Results were contrasted to the well-established transfer function, estimated between SAP and PI. Continuous arterial pressure recordings were obtained from healthy rats (N = 61) and beat-by-beat series of SAP and PI were generated. Low-pass (LP) and high-pass (HP) filtered series of SAP and PI were created by filtering the original series with a cutoff frequency of 0.8 Hz. Original series were analyzed by either the sequence method or cross-spectral analysis (transfer function) at low- (LF) and high- (HF) frequency bands, while filtered series were evaluated only by the sequence method. Baroreflex sensitivity (BRS) and BEI of original series, calculated by sequence method, was highly (85–90%) determined by HP series, with no significant association between original and LP series. A high correlation (>0.7) was found between the BRS estimated from original series (sequence method) and HF band (transfer function), as well as for LP series (sequence method) and LF band (transfer function). These findings confirmed the hypothesis that the sequence method quantifies only the high-frequency components of the baroreflex, neglecting the low-frequency influences, such as the Mayer waves. Therefore, we propose using both the original and LP filtered time series for a broader assessment of the baroreflex function using the sequence method.
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Affiliation(s)
| | | | | | - Hélio Cesar Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rubens Fazan
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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11
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Wang Y, Yin J, Wang C, Hu H, Li X, Xue M, Liu J, Cheng W, Wang Y, Li Y, Shi Y, Tan J, Li X, Liu F, Liu Q, Yan S. Microglial Mincle receptor in the PVN contributes to sympathetic hyperactivity in acute myocardial infarction rat. J Cell Mol Med 2018; 23:112-125. [PMID: 30353660 PMCID: PMC6307841 DOI: 10.1111/jcmm.13890] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/08/2018] [Indexed: 01/12/2023] Open
Abstract
Malignant ventricular arrhythmias (VAs) following myocardial infarction (MI) is a lethal complication resulting from sympathetic nerve hyperactivity. Numerous evidence have shown that inflammation within the paraventricular nucleus (PVN) participates in sympathetic hyperactivity. Our aim was to explore the role of Macrophage‐inducible C‐type lectin (Mincle) within the PVN in augmenting sympathetic activity following MI,and whether NOD‐like receptor family pyrin domain‐containing 3 (NLRP3) inflammasome/IL‐1β axis is involved in this activity. MI was induced by coronary artery ligation. Mincle expression localized in microglia within the PVN was markedly increased at 24 hours post‐MI together with sympathetic hyperactivity, as indicated by measurement of the renal sympathetic nerve activity (RSNA) and norepinephrine (NE) concentration. Mincle‐specific siRNA was administrated locally to the PVN, which consequently decreased microglial activation and sympathetic nerve activity. The MI rats exhibited a higher arrhythmia score after programmed electric stimulation than that treated with Mincle siRNA, suggesting that the inhibition of Mincle attenuated foetal ventricular arrhythmias post‐MI. The underlying mechanism of Mincle in sympathetic hyperactivity was investigated in lipopolysaccharide (LPS)‐primed naïve rats. Recombinant Sin3A‐associated protein 130kD (rSAP130), an endogenous ligand for Mincle, induced high levels of NLRP3 and mature IL‐1β protein. PVN‐targeted injection of NLRP3 siRNA or IL‐1β antagonist gevokizumab attenuated sympathetic hyperactivity. Together, the data indicated that the knockdown of Mincle in microglia within the PVN prevents VAs by attenuating sympathetic hyperactivity and ventricular susceptibility, in part by inhibiting its downstream NLRP3/IL‐1β axis following MI. Therapeutic interventions targeting Mincle signalling pathway could constitute a novel approach for preventing infarction injury.
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Affiliation(s)
- Yu Wang
- School of Medicine, Shandong University, Jinan, China
| | - Jie Yin
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Cailing Wang
- Department of Endocrinology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Hesheng Hu
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Xiaolu Li
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Mei Xue
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Ju Liu
- Medical Research Center, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Wenjuan Cheng
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Ye Wang
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Yan Li
- Medical Research Center, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Yugen Shi
- School of Medicine, Shandong University, Jinan, China
| | - Jiayu Tan
- School of Medicine, Shandong University, Jinan, China
| | - Xinran Li
- Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Fuhong Liu
- Medical Research Center, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Qiang Liu
- Medical Research Center, Qianfoshan Hospital of Shandong Province, Jinan, China
| | - Suhua Yan
- School of Medicine, Shandong University, Jinan, China.,Department of Cardiology, Qianfoshan Hospital of Shandong Province, Jinan, China
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12
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Silva LEV, Katayama PL. Baroreflex-mediated sympathetic overactivation induced by mental stress in post-traumatic stress disorder depends on the type of stressor. J Physiol 2017; 595:5757-5758. [PMID: 28714262 DOI: 10.1113/jp274859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Luiz Eduardo Virgilio Silva
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil.,Department of Computer Science, Institute of Mathematics and Computer Science, University of São Paulo, SP, Brazil
| | - Pedro Lourenço Katayama
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
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13
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Watso JC, Babcock MC, Migdal KU, Robinson AT. The baroreflex effectiveness index as an early marker of autonomic dysfunction in heart failure. J Physiol 2017; 595:5013-5014. [PMID: 28605038 DOI: 10.1113/jp274664] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Joseph C Watso
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Matthew C Babcock
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Kamila U Migdal
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
| | - Austin T Robinson
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
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