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arterial baroreflex

Jason R Carter, Daniela Grimaldi, Ida T Fonkoue, Lisa Medalie, Babak Mokhlesi, Eve Van Cauter
Study Objectives: Chronic insomnia affects up to 15% of adults. Recent cross-sectional and prospective epidemiological studies report an association between insomnia and hypertension, including incident hypertension, yet mechanisms underlying the association remain unknown. We hypothesized that subjects with chronic insomnia would have elevated sympathetic neural outflow, blunted baroreflex sensitivity, and augmented sympathetic neural and cardiovascular reactivity to stress when compared to good-sleeper controls...
March 7, 2018: Sleep
Milene R Malheiros-Lima, Washington Pires, Ivana A T Fonseca, Julliane V Joviano-Santos, Anderson J Ferreira, Cândido C Coimbra, Nilo R V Lima, Samuel P Wanner
This study aimed to investigate the chronic effects of caudal artery denervation on morphometric parameters of the tail vascular smooth muscle and on physical exercise-induced thermoregulatory and cardiovascular adjustments in rats. Male Wistar rats were subjected to caudal artery denervation or the sham procedure. Approximately 26-28 days after these procedures, their thermoregulatory and cardiovascular parameters were evaluated at rest and during or following a fatiguing treadmill run. At the end of the experiments, the rats were euthanized, and samples of their tails were removed to evaluate morphometric parameters of the vascular smooth muscle surrounding the caudal artery...
2018: Frontiers in Physiology
Hiromi Yamamoto, Toru Kawada, Shuji Shimizu, Kazunori Uemura, Masashi Inagaki, Kazuyoshi Kakehi, Yoshitaka Iwanaga, Kanji Fukuda, Tadayoshi Miyamoto, Shunichi Miyazaki, Masaru Sugimachi
AIMS: To assess the acute effects of intravenous ivabradine, a selective bradycardic agent, on carotid sinus baroreflex-mediated sympathetic arterial pressure (AP) and heart rate (HR) responses. METHODS AND RESULTS: In anesthetized and vagotomized Wistar-Kyoto rats (n=6), carotid sinus baroreceptor regions were isolated. Changes in splanchnic sympathetic nerve activity (SNA), AP, and HR in response to a step-wise pressure input were examined before and after intravenous ivabradine (2mg/kg)...
April 15, 2018: International Journal of Cardiology
Catherine L Tegeler, Lee Gerdes, Hossam A Shaltout, Jared F Cook, Sean L Simpson, Sung W Lee, Charles H Tegeler
BACKGROUND: Military-related post-traumatic stress (PTS) is associated with numerous symptom clusters and diminished autonomic cardiovascular regulation. High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology that produces real-time translation of dominant brain frequencies into audible tones of variable pitch and timing to support the auto-calibration of neural oscillations. We report clinical, autonomic, and functional effects after the use of HIRREM® for symptoms of military-related PTS...
December 22, 2017: Military Medical Research
Daniel Canuto, Kwitae Chong, Cayley Bowles, Erik P Dutson, Jeff D Eldredge, Peyman Benharash
A computational tool is developed for simulating the dynamic response of the human cardiovascular system to various stressors and injuries. The tool couples zero-dimensional models of the heart, pulmonary vasculature, and peripheral vasculature to one-dimensional models of the major systemic arteries. To simulate autonomic response, this multiscale circulatory model is integrated with a feedback model of the baroreflex, allowing control of heart rate, cardiac contractility, and peripheral impedance. The performance of the tool is demonstrated in two scenarios: neurogenic hypertension by sustained stimulation of the sympathetic nervous system, and an acute 10 percent hemorrhage from the left femoral artery...
March 2, 2018: International Journal for Numerical Methods in Biomedical Engineering
Sushmita Purkayastha, Kaitlyn Maffuid, Xiaojie Zhu, Rong Zhang, Peter B Raven
PURPOSE: This preliminary study tested the hypothesis that the carotid baroreflex (CBR) mediated sympathoexcitation regulates cerebral blood flow (CBF) at rest and during dynamic exercise. METHODS: In seven healthy subjects (26 ± 1 years), oscillatory neck pressure (NP) stimuli of + 40 mmHg were applied to the carotid baroreceptors at a pre-determined frequency of 0.1 Hz at rest, low (10 ± 1W), and heavy (30 ± 3W) exercise workloads (WLs) without (control) and with α - 1 adrenoreceptor blockade (prazosin)...
March 1, 2018: European Journal of Applied Physiology
Jacqueline K Limberg, Elizabeth P Ott, Walter W Holbein, Sarah Elizabeth Baker, Timothy B Curry, Wayne T Nicholson, Michael J Joyner, J Kevin Shoemaker
To study how changes in baroreceptor afferent activity affect patterns of sympathetic neural activation, we manipulated arterial blood pressure using intravenous nitroprusside (NTP) and phenylephrine (PE) and measured action potential (AP) patterns with wavelet-based methodology. We hypothesized: 1) Baroreflex unloading (NTP) would increase firing of low-threshold axons and recruitment of latent axons, and 2) Baroreflex loading (PE) would decrease firing of low-threshold axons. Heart rate (HR, ECG), arterial blood pressure (BP, brachial catheter), and muscle sympathetic nerve activity (MSNA, microneurography of the peroneal nerve) were measured at baseline and during steady-state systemic, intravenous NTP (0...
February 28, 2018: Journal of Neurophysiology
André L Teixeira, Milena Samora, Jeann L Sabino-Carvalho
The cardiovascular response to exercise is governed by both central and peripheral mechanisms that promote alterations in parasympathetic and sympathetic neural activities to the heart and blood vessels to meet the metabolic demands of working skeletal muscle in an intensity-dependent manner. This article is protected by copyright. All rights reserved.
February 28, 2018: Journal of Physiology
Ricardo S Oliveira, Alan R Barker, Florian Debras, Alexandra O'Doherty, Craig A Williams
Improvements in the autonomic and vascular systems are implicated in cardiovascular disease risk reduction. Baroreflex sensitivity (BRS) is composed of vascular and autonomic components. This study aimed to investigate between- and within-day reliability of BRS and its autonomic and vascular determinants in adolescents. Thirteen male adolescents (14·1 ± 0·5 y) participated in this study. For between-day reliability, participants completed four experimental visits separated by a minimum of 48-h. For within-day reliability, participants repeated BRS assessments three times in the morning with one hour between the measures...
February 23, 2018: Clinical Physiology and Functional Imaging
Eric A Schmidt, Fabien Despas, Anne Pavy-Le Traon, Zofia Czosnyka, John D Pickard, Kamal Rahmouni, Atul Pathak, Jean M Senard
Intracranial pressure (ICP) is the pressure within the cranium . ICP rise compresses brain vessels and reduces cerebral blood delivery. Massive ICP rise leads to cerebral ischemia, but it is also known to produce hypertension, bradycardia and respiratory irregularities due to a sympatho-adrenal mechanism termed Cushing response. One still unresolved question is whether the Cushing response is a non-synaptic acute brainstem ischemic mechanism or part of a larger physiological reflex for arterial blood pressure control and homeostasis regulation...
2018: Frontiers in Physiology
Josária Ferraz Amaral, Diana de Medeiros Andrade Borsato, Isabelle Magalhães Guedes Freitas, Edgar Toschi-Dias, Daniel Godoy Martinez, Mateus Camaroti Laterza
BACKGROUND: Individuals with a family history of systemic arterial hypertension (FHSAH) and / or prehypertension have a higher risk of developing this pathology. OBJECTIVE: To evaluate the autonomic and vascular functions of prehypertensive patients with FHSAH. METHODS: Twenty-five young volunteers with FHSAH, 14 normotensive and 11 prehypertensive subjects were submitted to vascular function evaluation by forearm vascular conductance(VC) during resting and reactive hyperemia (Hokanson®) and cardiac and peripheral autonomic modulation, quantified, respectively, by spectral analysis of heart rate (ECG) and systolic blood pressure (SBP) (FinometerPRO®)...
February 19, 2018: Arquivos Brasileiros de Cardiologia
Cristian Sevcencu, Thomas N Nielsen, Johannes J Struijk
OBJECTIVES: As the left vagus nerve (LVN) mediates a baroreflex blood pressure (BP) decrease, LVN stimulation (LVNS) could be a therapy for hypertension. Moreover, LVNS could elegantly be adjusted to the patient's actual BP and physical activity by using the neural information about BP and respiration extractable from LVN. However, unselective LVNS will trigger undesirable side-effects and therefore we here investigated the feasibility of using an intraneural electrode for extracting BP and respiration markers from the LVN and for selective LVNS...
February 14, 2018: Neuromodulation: Journal of the International Neuromodulation Society
Luiz Fernando Veríssimo, Vinicius Lucca Volpini, Viviane Batista Estrada, Natália Kimie Matsubara, Marcus Vinicius Gomes, Leonardo Barbosa Moraes Resstel, Fernando Morgan Aguiar Correa, Gislaine Garcia Pelosi
Considering depression is three times more common in cardiac patients compared to the normal population and selective serotonin reuptake inhibitors (SSRI) as drug of choice for treating patients with cardiovascular disease and depression, our work aims to evaluate the cardiovascular effects of treatment for 21 days with escitalopram (5 mg/kg/day, ip) in rats. The treatment caused an increase in mean arterial pressure concomitant with a decrease in heart rate. Concerning heart rate variability, there was a significant reduction in the sympathetic component and an elevation of the parasympathetic component, indicating that escitalopram caused an autonomic imbalance with parasympathetic predominance...
April 5, 2018: European Journal of Pharmacology
Vlasta Bari, Marco Ranucci, Beatrice De Maria, Beatrice Cairo, Valeria Pistuddi, Alberto Porta
BACKGROUND: Postoperative atrial fibrillation (AF) might be favored by cardiovascular control impairment. We hypothesize that cardiovascular regulation indexes derived from directional model-based analysis of the spontaneous fluctuations of heart period (HP) and systolic arterial pressure (SAP) can identify subjects at risk to develop AF after coronary artery bypass graft (CABG) surgery. METHODS: Beat-to-beat HP and SAP series were derived from electrocardiogram (ECG) and invasive arterial pressure recorded for 5 min just before CABG surgery in conscious condition...
February 2, 2018: International Journal of Cardiology
Gábor Holló
Both exfoliation syndrome (XFS) and exfoliation glaucoma (XFG) are associated with systemic vascular diseases and abnormalities. Though no uniform relationship between XFS/XFG and clinical systemic vascular diseases has been established across various populations, vascular dysfunction with or without clinically significant consequences has been repeatedly detected with both epidemiological and pathophysiological methods. Elevated plasma homocysteine, reduced cutaneous capillary flow reactions, damaged conduit artery dysfunction, impaired baroreflex sensitivity, parasympathetic cardiovascular neuropathy, and pathological heart rate variability indices have all been shown in XFS and XFG...
February 6, 2018: Journal of Glaucoma
Thomas J Hureau, Joshua C Weavil, Taylor S Thurston, Ryan M Broxterman, Ashley D Nelson, Amber D Bledsoe, Jacob E Jessop, Russell S Richardson, D Walter Wray, Markus Amann
This study sought to comprehensively investigate the role of metabolically and mechanically sensitive group III/IV muscle afferents in carotid baroreflex responsiveness and resetting during both electrically-evoked (EVO, no central command) and voluntary (VOL, requiring central command) isometric single-leg knee-extension (15% of MVC) exercise. Participants (n = 8) were studied under control conditions (CTRL) and following lumbar intrathecal fentanyl injection (FENT) to inhibit μ-opioid receptor-sensitive lower limb muscle afferents...
February 1, 2018: Journal of Physiology
Derek Nelson, Dane A Crossley, Ruth M Elsey, Kevin B Tate
American alligators (Alligator mississippiensis) deposit eggs in a mound nest, potentially subjecting embryos to daily variations in temperature. Whilst adult crocodilian cardiovascular responses to changes in temperature have been investigated, similar studies in alligator embryos are limited. We investigated cardiovascular function of embryonic alligators during heating and cooling as well as at different temperatures. We measured arterial blood pressure (Pm) and heart rate (fH) in response to cooling (30-26 °C), heating (26-36 °C), followed by a reciprocal cooling event (36-26 °C) and assessed the cardiac baroreflex at 30 and 36 °C...
January 27, 2018: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
Takeshi Tohyama, Keita Saku, Toru Kawada, Takuya Kishi, Keimei Yoshida, Takuya Nishikawa, Hiroshi Mannoji, Kazuhiro Kamada, Kenji Sunagawa, Hiroyuki Tsutsui
BACKGROUND: Lipopolysaccharide (LPS) induces acute inflammation, activates sympathetic nerve activity (SNA) and alters hemodynamics. Since the arterial baroreflex is a negative feedback system to stabilize arterial pressure (AP), examining the arterial baroreflex function is a prerequisite to understanding complex hemodynamics under LPS challenge. We investigated the impact of LPS-induced acute inflammation on SNA and AP regulation by performing baroreflex open-loop analysis. METHODS: Ten anesthetized Sprague-Dawley rats were used...
2018: PloS One
Stefana Catalina Bilha, Alexandru Burlacu, Dimitrie Siriopol, Luminita Voroneanu, Adrian Covic
BACKGROUND: Although chronic kidney disease (CKD) is an independent risk factor for stroke, official recommendations for the primary prevention of stroke in CKD are generally lacking. SUMMARY: We searched PubMed and ISI Web of Science for randomised controlled trials, observational studies, reviews, meta-analyses and guidelines referring to measures of stroke prevention or to the treatment of stroke-associated risk factors (cardiovascular disease in general and atrial fibrillation (AF), arterial hypertension or carotid artery disease in particular) among the CKD population...
January 9, 2018: Cerebrovascular Diseases
Timothée Fontolliet, Pietro Gianella, Vincent Pichot, Jean-Claude Barthélémy, Paola Gasche-Soccal, Guido Ferretti, Frédéric Lador
The effects of lung afferents denervation on cardiovascular regulation can be assessed on bilateral lung transplantation patients. The high-frequency component of heart rate variability is known to be synchronous with breathing frequency. Then, if heart beat is neurally modulated by breathing frequency, we may expect disappearance of high frequency of heart rate variability in bilateral lung transplantation patients. On 11 patients and 11 matching healthy controls, we measured R-R interval (electrocardiography), blood pressure (Portapres® ) and breathing frequency (ultrasonic device) in supine rest, during 10-min free breathing, 10-min cadenced breathing (0·25 Hz) and 5-min handgrip...
January 9, 2018: Clinical Physiology and Functional Imaging
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