1
|
Rangon CM, Krantic S, Moyse E, Fougère B. The Vagal Autonomic Pathway of COVID-19 at the Crossroad of Alzheimer's Disease and Aging: A Review of Knowledge. J Alzheimers Dis Rep 2020; 4:537-551. [PMID: 33532701 PMCID: PMC7835993 DOI: 10.3233/adr-200273] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2020] [Indexed: 12/11/2022] Open
Abstract
Coronavirus Disease 2019 (COVID-19) pandemic-triggered mortality is significantly higher in older than in younger populations worldwide. Alzheimer's disease (AD) is related to aging and was recently reported to be among the major risk factors for COVID-19 mortality in older people. The symptomatology of COVID-19 indicates that lethal outcomes of infection rely on neurogenic mechanisms. The present review compiles the available knowledge pointing to the convergence of COVID-19 complications with the mechanisms of autonomic dysfunctions in AD and aging. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is prone to neuroinvasion from the lung along the vagus nerve up to the brainstem autonomic nervous centers involved in the coupling of cardiovascular and respiratory rhythms. The brainstem autonomic network allows SARS-CoV-2 to trigger a neurogenic switch to hypertension and hypoventilation, which may act in synergy with aging- and AD-induced dysautonomias, along with an inflammatory "storm". The lethal outcomes of COVID-19, like in AD and unhealthy aging, likely rely on a critical hypoactivity of the efferent vagus nerve cholinergic pathway, which is involved in lowering cardiovascular pressure and systemic inflammation tone. We further discuss the emerging evidence supporting the use of 1) the non-invasive stimulation of vagus nerve as an additional therapeutic approach for severe COVID-19, and 2) the demonstrated vagal tone index, i.e., heart rate variability, via smartphone-based applications as a non-serological low-cost diagnostic of COVID-19. These two well-known medical approaches are already available and now deserve large-scale testing on human cohorts in the context of both AD and COVID-19.
Collapse
Affiliation(s)
- Claire-Marie Rangon
- Pain and Neuromodulation Unit, Division of Neurosurgery, Hôpital Fondation Ophtalmologique A. De Rothschild, Paris, France
| | - Slavica Krantic
- Sorbonne Université, St. Antoine Research Center (CRSA), Inserm UMRS-938, Hopital St-Antoine, Paris, France
| | - Emmanuel Moyse
- INRAE Centre Val-de-Loire, Physiology of Reproduction and Behavior Unit (PRC, UMR-85), Team ER2, Nouzilly, France
| | - Bertrand Fougère
- Division of Geriatric Medicine, Tours University Hospital, Tours, France
- Education, Ethics, Health (EA 7505), Tours University, Tours, France
| |
Collapse
|
2
|
Impact of Peripheral α7-Nicotinic Acetylcholine Receptors on Cardioprotective Effects of Donepezil in Chronic Heart Failure Rats. Cardiovasc Drugs Ther 2020; 35:877-888. [PMID: 32860618 DOI: 10.1007/s10557-020-07062-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/24/2020] [Indexed: 01/14/2023]
Abstract
PURPOSE Pharmacological modulation of parasympathetic activity with donepezil, an acetylcholinesterase inhibitor, improves the long-term survival of rats with chronic heart failure (CHF) after myocardial infarction (MI). However, its mechanism is not well understood. The α7-nicotinic acetylcholine receptor (α7-nAChR) reportedly plays an important role in the cholinergic anti-inflammatory pathway. The purpose of this study was to examine whether blockade of α7-nAChR, either centrally or peripherally, affects cardioprotection by donepezil during CHF. METHODS One-week post-MI, the surviving rats were implanted with an electrocardiogram or blood pressure transmitter to monitor hemodynamics continuously. Seven days after implantation, the MI rats (n = 74) were administered donepezil in drinking water or were untreated (UT). Donepezil-treated MI rats were randomly assigned to the following four groups: peripheral infusion of saline (SPDT) or an α7-nAChR antagonist methyllycaconitine (α7PDT), and brain infusion of saline (SBDT) or the α7-nAChR antagonist (α7BDT). RESULTS After the 4-week treatment, the role of α7-nAChR was evaluated using hemodynamic parameters, neurohumoral states, and histological and morphological assessment. Between the peripheral infusion groups, α7PDT (vs. SPDT) showed significantly increased heart weight and cardiac fibrosis, deteriorated hemodynamics, increased plasma neurohumoral and cytokine levels, and significantly decreased microvessel density (as assessed by anti-von Willebrand factor-positive cells). In contrast, between the brain infusion groups, α7BDT (vs. SBDT) showed no changes in either cardiac remodeling or hemodynamics. CONCLUSION Peripheral blockade of α7-nAChR significantly attenuated the cardioprotective effects of donepezil in CHF rats, whereas central blockade did not. This suggests that peripheral activation of α7-nAChR plays an important role in cholinergic pharmacotherapy for CHF.
Collapse
|
3
|
Li M, Zheng C, Kawada T, Inagaki M, Uemura K, Sugimachi M. Chronic vagal nerve stimulation exerts additional beneficial effects on the beta-blocker-treated failing heart. J Physiol Sci 2019; 69:295-303. [PMID: 30414045 PMCID: PMC10717668 DOI: 10.1007/s12576-018-0646-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/29/2018] [Indexed: 12/20/2022]
Abstract
Vagal nerve stimulation (VNS) induces bradycardia in chronic heart failure (CHF). We hypothesized that beta-blocker would cover the beneficial effects of VNS on CHF if the anti-beta-adrenergic effect was the main VNS effect. This study investigated the effects of VNS on cardiac remodeling in rats with CHF treated with metoprolol. Two weeks after myocardial infarction, surviving rats were randomly assigned to groups of sham stimulation (SS), sham stimulation with metoprolol (SSM), or VNS with metoprolol (VSM). Compared to the SS group, heart rate was significantly reduced in the SSM and VSM groups. Hemodynamic assessments showed that VSM rats maintained better cardiac pump function and presented higher cardiac index and lower heart weight than SSM rats. VSM was also associated with lower plasma brain natriuretic peptide and norepinephrine levels than SSM. VSM but not SSM improved the 50-day survival rate compared with the SS group. The results suggest that VNS may exert its beneficial effects on the failing heart independently of its anti-beta-adrenergic mechanism.
Collapse
Affiliation(s)
- Meihua Li
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| | - Can Zheng
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan.
| | - Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| | - Masashi Inagaki
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| | - Kazunori Uemura
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| |
Collapse
|
4
|
Neuromodulation Therapies for Cardiac Disease. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00129-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Kawada T, Li M, Zheng C, Sugimachi M. Acute Effects of Vagotomy on Baroreflex Equilibrium Diagram in Rats with Chronic Heart Failure. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2016; 10:139-47. [PMID: 27594790 PMCID: PMC5003122 DOI: 10.4137/cmc.s38443] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/01/2016] [Accepted: 08/05/2016] [Indexed: 01/01/2023]
Abstract
The arterial baroreflex system can be divided into the neural arc, from pressure input to efferent sympathetic nerve activity (SNA), and the peripheral arc, from SNA to arterial pressure (AP). Plotting the neural and peripheral arcs on a pressure–SNA plane yields a baroreflex equilibrium diagram. We examined the effects of vagotomy on the open-loop static characteristics of the carotid sinus baroreflex in normal control rats (NC, n = 10) and rats with heart failure after myocardial infarction (MI, n = 10). In the NC group, vagotomy shifted the neural arc toward higher SNA and decreased the slope of the peripheral arc. Consequently, the operating-point SNA increased without a significant change in the operating-point AP on the baroreflex equilibrium diagram. These vagotomy-induced effects were not observed in the MI group, suggesting a loss of vagal modulation of the carotid sinus baroreflex function in heart failure.
Collapse
Affiliation(s)
- Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Meihua Li
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Can Zheng
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| |
Collapse
|
6
|
Kawada T, Akiyama T, Li M, Zheng C, Turner MJ, Shirai M, Sugimachi M. Acute arterial baroreflex-mediated changes in plasma catecholamine concentrations in a chronic rat model of myocardial infarction. Physiol Rep 2016; 4:4/15/e12880. [PMID: 27495297 PMCID: PMC4985546 DOI: 10.14814/phy2.12880] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 11/24/2022] Open
Abstract
While it may be predictable that plasma norepinephrine (NE) concentration changes with efferent sympathetic nerve activity (SNA) in response to baroreceptor pressure inputs, an exact relationship between SNA and plasma NE concentration remains to be quantified in heart failure. We examined acute baroreflex-mediated changes in plasma NE and epinephrine (Epi) concentrations in normal control (NC) rats and rats with myocardial infarction (MI) (n = 6 each). Plasma NE concentration correlated linearly with SNA in the NC group (slope: 2.17 ± 0.26 pg mL(-1) %(-1), intercept: 20.0 ± 18.2 pg mL(-1)) and also in the MI group (slope: 19.20 ± 6.45 pg mL(-1) %(-1), intercept: -239.6 ± 200.0 pg mL(-1)). The slope was approximately nine times higher in the MI than in the NC group (P < 0.01). Plasma Epi concentration positively correlated with SNA in the NC group (slope: 1.65 ± 0.79 pg mL(-1) %(-1), intercept: 115.0 ± 69.5 pg mL(-1)) and also in the MI group (slope: 7.74 ± 2.20 pg mL(-1) %(-1), intercept: 24.7 ± 120.1 pg mL(-1)). The slope was approximately 4.5 times higher in the MI than in the NC group (P < 0.05). Intravenous administration of desipramine (1 mg kg(-1)) significantly increased plasma NE concentration but decreased plasma Epi concentration in both groups, suggesting that neuronal NE uptake had contributed to the reduction in plasma NE concentration. These results indicate that high levels of plasma catecholamine in MI rats were still under the influence of baroreflex-mediated changes in SNA, and may provide additional rationale for applying baroreflex activation therapy in patients with chronic heart failure.
Collapse
Affiliation(s)
- Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Tsuyoshi Akiyama
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Meihua Li
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Can Zheng
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Michael J Turner
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Mikiyasu Shirai
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| |
Collapse
|
7
|
Ciriello J, Caverson MM. Effect of estrogen on vagal afferent projections to the brainstem in the female. Brain Res 2016; 1636:21-42. [PMID: 26835561 DOI: 10.1016/j.brainres.2016.01.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Revised: 01/19/2016] [Accepted: 01/25/2016] [Indexed: 12/13/2022]
Abstract
The effects of 17β-estradiol (E) on the distribution and density of brainstem projections of small or large diameter primary vagal afferents were investigated in Wistar rats using transganglionic transport of wheat germ agglutinin- (WGA; preferentially transported by non-myelinated afferent C-fibers; 2%), or cholera toxin B-subunit- (CTB, 5%; preferentially transported by large myelinated afferent A-fibers) conjugated horseradish peroxidase (HRP) in combination with the tetramethylbenzidine method in age matched ovariectomized (OVX) only or OVX and treated with E (OVX+E; 30 pg/ml plasma) females for 12 weeks. Additionally, these projections were compared to aged matched males. Unilateral microinjection of WGA-HRP into the nodose ganglion resulted in dense anterograde labeling bilaterally, with an ipsilateral predominance in several subnuclei of the nucleus of the solitary tract (NTS) and in area postrema that was greatest in OVX+E animals compared to OVX only and males. Moderately dense anterograde labeling was also observed in paratrigeminal nucleus (PAT) of the OVX+E animals. CTB-HRP produced less dense anterograde labeling in the NTS complex, but had a wider distribution within the brainstem including the area postrema, dorsal motor nucleus of the vagus, PAT, the nucleus ambiguus complex and ventrolateral medulla in all groups. The distribution of CTB-HRP anterograde labeling was densest in OVX+E, less dense in OVX only females and least dense in male rats. Little, if any, labeling was found within PAT in males using either WGA-or CTB-HRP. Taken together, these data suggest that small, non-myelinated (WGA-labeled) and large myelinated (CTB-labeled) diameter vagal afferents projecting to brainstem autonomic areas are differentially affected by circulating levels of estrogen. These effects of estrogen on connectivity may contribute to the sex differences observed in central autonomic mechanisms between gender, and in females with and without estrogen.
Collapse
Affiliation(s)
- John Ciriello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1 Canada.
| | - Monica M Caverson
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1 Canada
| |
Collapse
|
8
|
Kawada T, Sugimachi M. Open-loop static and dynamic characteristics of the arterial baroreflex system in rabbits and rats. J Physiol Sci 2016; 66:15-41. [PMID: 26541155 PMCID: PMC4742515 DOI: 10.1007/s12576-015-0412-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 09/30/2015] [Indexed: 02/07/2023]
Abstract
The arterial baroreflex system is the most important negative feedback system for stabilizing arterial pressure (AP). This system serves as a key link between the autonomic nervous system and the cardiovascular system, and is thus essential for understanding the pathophysiology of cardiovascular diseases and accompanying autonomic abnormalities. This article focuses on an open-loop systems analysis using a baroreceptor isolation preparation to identify the characteristics of two principal subsystems of the arterial baroreflex system, namely, the neural arc from pressure input to efferent sympathetic nerve activity (SNA) and the peripheral arc from SNA to AP. Studies on the static and dynamic characteristics of the two arcs under normal physiological conditions and also under various interventions including diseased conditions are to be reviewed. Quantitative understanding of the arterial baroreflex function under diseased conditions would help develop new treatment strategies such as electrical activation of the carotid sinus baroreflex for drug-resistant hypertension.
Collapse
Affiliation(s)
- Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan.
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 5-7-1 Fujishirodai, Suita, Osaka, 565-8565, Japan
| |
Collapse
|
9
|
Acute effects of arterial baroreflex on sympathetic nerve activity and plasma norepinephrine concentration. Auton Neurosci 2015; 186:62-8. [PMID: 25458434 DOI: 10.1016/j.autneu.2014.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/06/2014] [Accepted: 10/15/2014] [Indexed: 02/07/2023]
Abstract
Arterial pressure (AP) elevates as a logarithmic function of exogenously administered dose of norepinephrine (NE). In contrast, AP is nearly linearly correlated with efferent sympathetic nerve activity (SNA) during acute baroreflex intervention. The present study aimed at quantifying the relationship between SNA and plasma NE concentration during acute baroreflex intervention. Carotid sinus regions were isolated from systemic circulation in five Wistar Kyoto rats, and carotid sinus pressure was changed among 60, 100, 120, 140, and 180 mm Hg every 2 min. Arterial blood (0.2 ml) was obtained at each pressure level for plasma NE measurement. Maximum AP and minimum AP were 153.34 ± 6.28 and 67.31 ± 4.92 mm Hg, respectively, in response to pressure perturbation. Plasma NE correlated linearly with SNA for individual animal data (slope: 0.957 ± 0.090 pg · ml(-1) · %(-1), intercept: 46.57 ± 7.22 pg/ml, r(2): ranged from 0.923 to 0.992) and also for group averaged data (NE = 0.956 × SNA + 47.97, r(2 )= 0.982). Blockade of neuronal NE uptake by intravenous desipramine (1 mg/kg) administration increased the slope (2.966 ± 0.686 pg · ml(-1) · %(-1), P < 0.05) and the intercept (168.73 ± 28.53 pg/ml, P < 0.01) of the plasma NE-SNA relationship. These results indicate that the relationship between SNA and plasma NE concentration was nearly linear within the normal physiological range of acute baroreflex control of AP. While plasma NE concentration can reflect changes in SNA, it may also overestimate the sympathetic outflow from the central nervous system when neuronal NE uptake is impaired systemically.
Collapse
|
10
|
Turner MJ, Kawada T, Shimizu S, Fukumitsu M, Sugimachi M. Open-loop characteristics of the arterial baroreflex after blockade of unmyelinated baroreceptors with resiniferatoxin. Auton Neurosci 2015; 193:38-43. [PMID: 26049262 DOI: 10.1016/j.autneu.2015.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/25/2015] [Accepted: 05/26/2015] [Indexed: 02/01/2023]
Abstract
Arterial baroreceptors can be divided into two categories dependent on whether their axons are myelinated (A-fiber) or unmyelinated (C-fiber). We investigated the effect of periaxonal resiniferatoxin (RTX), a blocker of C-fiber baroreceptor activity, on the open-loop static characteristics of the arterial baroreflex. The baroreceptor region of the right aortic depressor nerve was isolated, and intra-baroreceptor region pressure (BRP) was changed from 60 to 180 mm Hg in 10 anesthetized Sprague-Dawley rats. Open-loop static characteristics of the neural arc from BRP to efferent sympathetic nerve activity (SNA), peripheral arc from SNA to arterial pressure (AP), and total reflex arc from BRP to AP were estimated. Although blocking C-fiber activity with RTX resulted in a lower response range (33.7±4.6% and 49.4±4.8%, P<0.01) and higher minimum SNA (78.0±4.7% and 53.6±5.0%, P<0.001) of the steady-state neural arc, the peak SNA response to BRP was greater at a BRP of 160 mm Hg (-37.87±5.83% and -26.28±4.90%, P=0.01). RTX also resulted in a lower response range (27.8±5.0 mm Hg and 40.9±5.2 mm Hg, P<0.01) and higher minimum AP (92.4±4.7 mm Hg and 79.1±4.9 mm Hg, P<0.001) of the total reflex arc. Despite these changes, the maximum slope of the neural arc and the maximum gain of the total reflex arc did not differ significantly after RTX. These data suggest that A-fiber baroreceptors can regulate AP and maintain the maximum gain when systemic AP is around the normal operating range. In contrast, C-fiber baroreceptors are critically important for reductions in SNA and AP when systemic AP is raised above the normal operating range.
Collapse
Affiliation(s)
- Michael J Turner
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
| | - Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan
| | - Shuji Shimizu
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan
| | - Masafumi Fukumitsu
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan; Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan; Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| |
Collapse
|
11
|
Kawada T, Sata Y, Shimizu S, Turner MJ, Fukumitsu M, Sugimachi M. Effects of tempol on baroreflex neural arc versus peripheral arc in normotensive and spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2015; 308:R957-64. [DOI: 10.1152/ajpregu.00525.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/23/2015] [Indexed: 11/22/2022]
Abstract
Although oxidative redox signaling affects arterial pressure (AP) regulation via modulation of vascular tone and sympathetic nerve activity (SNA), it remains unknown which effect plays a dominant role in the determination of AP in vivo. Open-loop systems analysis of the carotid sinus baroreflex was conducted to separately quantify characteristics of the neural arc from baroreceptor pressure input to SNA and the peripheral arc from SNA to AP in normotensive Wistar-Kyoto (WKY; n = 8) and spontaneously hypertensive rats (SHR; n = 8). Responses in SNA and AP to a staircase-wise increase in carotid sinus pressure were examined before and during intravenous administration of the membrane-permeable superoxide dismutase mimetic tempol (30 mg/kg bolus followed by 30 mg·kg−1·h−1). Two-way ANOVA indicated that tempol significantly decreased the response range of SNA (from 89.1 ± 2.4% to 60.7 ± 2.5% in WKY and from 77.5 ± 3.2% to 56.9 ± 7.3% in SHR, P < 0.001) without affecting the lower plateau of SNA (from 12.5 ± 2.4% to 9.5 ± 2.5% in WKY, and from 28.8 ± 2.8% to 30.4 ± 5.7% in SHR, P = 0.800) in the neural arc. While tempol did not affect the peripheral arc characteristics in WKY, it yielded a downward change in the regression line of AP vs. SNA in SHR. In conclusion, oxidative redox signaling plays an important role, not only in the pathological AP elevation, but also in the baroreflex-mediated physiological AP regulation. The effect of modulating oxidative redox signaling on the peripheral arc contributed to the determination of AP in SHR but not in WKY.
Collapse
Affiliation(s)
- Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
| | - Yusuke Sata
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
- Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Shuji Shimizu
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
| | - Michael J. Turner
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
| | - Masafumi Fukumitsu
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
- Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan; and
- Department of Artificial Organ Medicine, Faculty of Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| |
Collapse
|
12
|
Li Y, Xuan YH, Liu SS, Dong J, Luo JY, Sun ZJ. Short‑term vagal nerve stimulation improves left ventricular function following chronic heart failure in rats. Mol Med Rep 2015; 12:1709-16. [PMID: 25873055 PMCID: PMC4464404 DOI: 10.3892/mmr.2015.3597] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 03/10/2015] [Indexed: 01/01/2023] Open
Abstract
Increasing numbers of animal and clinical investigations have demonstrated the effectiveness of long-term electrical vagal nerve stimulation (VNS) on chronic heart failure (CHF). The present study investigated the effects of short-term VNS on the hemodynamics of cardiac remodeling and cardiac excitation-contraction coupling (ECP) in an animal model of CHF following a large myocardial infarction. At 3 weeks subsequent to ligation of the left coronary artery, the surviving rats were randomized into vagal and sham-stimulated groups. The right vagal nerve of the CHF rats was stimulated for 72 h. The vagal nerve was stimulated with rectangular pulses of 40 ms duration at 1 Hz, 5 V. The treated rats, compared with the untreated rats, had significantly higher left ventricular ejection fraction (54.86±9.73, vs. 45.60±5.51%; P=0.025) and left ventricular fractional shortening (25.31±6.30, vs. 15.42±8.49%; P=0.013), and lower levels of brain natriuretic peptide (10.07±2.63, vs. 19.95±5.22 ng/ml; P=0.001). The improvement in cardiac pumping function was accompanied by a decrease in left ventricular end diastolic volume (1.11±0.50, vs. 1.54±0.57 cm3; P=0.032) and left ventricular end systolic volume (0.50±0.28, vs. 0.87±0.36 cm3; P=0.007). Furthermore, the expression levels of ryanodine receptor type 2 (RyR2) and sarcoplasmic reticulum calcium adenosine triphosphatase (SERCA2) were significantly higher in the treated rats compared with the untreated rats (P=0.011 and P=0.001 for RyR2 and SERCA2, respectively). Therefore, VNS was beneficial to the CHF rats through the prevention of cardiac remodeling and improvement of cardiac ECP.
Collapse
Affiliation(s)
- Yan Li
- Department of Geriatrics, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Yan-Hua Xuan
- Department of Cardiology Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Shuang-Shuang Liu
- Department of Cardiology Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Jing Dong
- Department of Cardiology Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Jia-Ying Luo
- Department of Cardiology Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| | - Zhi-Jun Sun
- Department of Cardiology Medicine, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, P.R. China
| |
Collapse
|
13
|
Kawada T, Li M, Sata Y, Zheng C, Turner MJ, Shimizu S, Sugimachi M. Calibration of baroreflex equilibrium diagram based on exogenous pressor agents in chronic heart failure rats. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2015; 9:1-9. [PMID: 25698884 PMCID: PMC4319654 DOI: 10.4137/cmc.s18759] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/15/2014] [Accepted: 12/26/2014] [Indexed: 11/05/2022]
Abstract
A baroreflex equilibrium diagram describes the relation between input pressure and sympathetic nerve activity (SNA) and that between SNA and arterial pressure (AP). To calibrate the SNA axis (abscissa) of the baroreflex equilibrium diagram, the AP response to intravenous bolus injections of phenylephrine (0.2-50 μg/kg) or norepinephrine (NE, 0.02-5 μg/kg) was examined in normal control rats (NC, n = 9) and rats with chronic heart failure (CHF, n = 6). The maximum slope of the dose-effect curve was significantly smaller in the CHF group than in the NC group (57.3 ± 5.2 vs 80.9 ± 6.3 mmHg/decade for phenylephrine, 60.2 ± 7.8 vs 80.4 ± 5.9 mmHg/decade for NE; P < 0.01). The CHF/NC ratio of the maximum slope was used to calibrate SNA. While the calibrated baroreflex equilibrium diagram showed increased maximum SNA and operating-point SNA in CHF rats compared with NC rats, the magnitude of increase was smaller than that expected from the excess plasma NE concentration in CHF rats. Plasma NE concentration in the CHF group could be disproportionally high relative to SNA.
Collapse
Affiliation(s)
- Toru Kawada
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Meihua Li
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Yusuke Sata
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan. ; Department of Artificial Organ Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Can Zheng
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Michael J Turner
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Shuji Shimizu
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Masaru Sugimachi
- Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka, Japan. ; Department of Artificial Organ Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| |
Collapse
|