-
Current Aging Science Aug 2022This review outlines the normal heart rate and blood pressure response to active standing, the physiological mechanisms governing these, and the effect of ageing on the... (Review)
Review
OBJECTIVES
This review outlines the normal heart rate and blood pressure response to active standing, the physiological mechanisms governing these, and the effect of ageing on the responses.
METHODS
A literature search was conducted to identify articles investigating the normal heart rate and/or blood pressure response to standing.
RESULTS
Heart rate when standing increases and then decreases and recovers to baseline. Blood pressure responses are inverse. Skeletal muscle contraction and the baroreceptor reflex drive this. With ageing, heart rate response attenuates and the initial blood pressure response increases.
DISCUSSION
Normal heart rate and blood pressure responses are attributed to the baroreceptor reflex and skeletal muscle contraction. Decreased muscle strength and baroreceptor sensitivity are associated with ageing, suggesting a possible benefit in improving skeletal muscle strength to maintain an efficient response. Understanding these responses and their variation with ageing is clinically relevant and may be beneficial in improving rehabilitation outcomes.
Topics: Baroreflex; Blood Pressure; Heart Rate; Humans; Muscle Contraction; Pressoreceptors
PubMed: 35440341
DOI: 10.2174/1874609815666220419102648 -
Pharmacological Research Feb 2021Baroreflex plays a crucial role in regulation of arterial blood pressure (BP). Recently, Piezo1 and Piezo2, the mechanically-activated (MA) ion channels, have been...
Baroreflex plays a crucial role in regulation of arterial blood pressure (BP). Recently, Piezo1 and Piezo2, the mechanically-activated (MA) ion channels, have been identified as baroreceptors. However, the underlying molecular mechanism for regulating these baroreceptors in hypertension remains unknown. In this study, we used spontaneously hypertensive rats (SHR) and NG-Nitro-l-Arginine (L-NNA)- and Angiotensin II (Ang II)-induced hypertensive model rats to determine the role and mechanism of Piezo1 and Piezo2 in hypertension. We found that Piezo2 was dominantly expressed in baroreceptor nodose ganglia (NG) neurons and aortic nerve endings in Wistar-Kyoto (WKY) rats. The expression of Piezo2 not Piezo1 was significantly downregulated in these regions in SHR and hypertensive model rats. Electrophysiological results showed that the rapidly adapting mechanically-activated (RA-MA) currents and the responsive neuron numbers were significantly reduced in baroreceptor NG neurons in SHR. In WKY rats, the arterial BP was elevated by knocking down the expression of Piezo2 or inhibiting MA channel activity by GsMTx4 in NG. Knockdown of Piezo2 in NG also attenuated the baroreflex and increased serum norepinephrine (NE) concentration in WKY rats. Co-immunoprecipitation experiment suggested that Piezo2 interacted with Neural precursor cell-expressed developmentally downregulated gene 4 type 2 (Nedd4-2, also known as Nedd4L); Electrophysiological results showed that Nedd4-2 inhibited Piezo2 MA currents in co-expressed HEK293T cells. Additionally, Nedd4-2 was upregulated in NG baroreceptor neurons in SHR. Collectively, our results demonstrate that Piezo2 not Piezo1 may act as baroreceptor to regulate arterial BP in rats. Nedd4-2 induced downregulation of Piezo2 in baroreceptor NG neurons leads to hypertension in rats. Our findings provide a novel insight into the molecular mechanism for the regulation of baroreceptor Piezo2 and its critical role in the pathogenesis of hypertension.
Topics: Animals; Aorta, Thoracic; Baroreflex; Cells, Cultured; Humans; Hypertension; Ion Channels; Male; Nedd4 Ubiquitin Protein Ligases; Neurons; Nodose Ganglion; Pressoreceptors; Rats, Inbred SHR; Rats, Inbred WKY; Signal Transduction; Rats
PubMed: 33352230
DOI: 10.1016/j.phrs.2020.105391 -
Lin Chuang Er Bi Yan Hou Tou Jing Wai... Nov 2021With the continuous updating of head and neck surgery concepts and techniques, more and more head and neck surgeries are developing in the direction of... (Review)
Review
With the continuous updating of head and neck surgery concepts and techniques, more and more head and neck surgeries are developing in the direction of refinement.however, the more complete the surgery, the greater the possibility of subsequent nerve exposure and injury. Even a slight perturbation of the nerve may cause serious complications, such as pressure receptor failure.It is necessary to review the mechanisms and the characteristics of baroreceptor failure syndrome after head and neck tumor surgery.
Topics: Head; Head and Neck Neoplasms; Humans; Neck; Postoperative Complications; Pressoreceptors
PubMed: 34886615
DOI: 10.13201/j.issn.2096-7993.2021.11.020 -
Trends in Cardiovascular Medicine Oct 2020Atrial fibrillation (AF) is a rapidly growing clinical problem in routine practice, both for cardiologists as well as general practitioners. Current therapies aimed at... (Review)
Review
Atrial fibrillation (AF) is a rapidly growing clinical problem in routine practice, both for cardiologists as well as general practitioners. Current therapies aimed at the management of AF include anti-arrhythmic drug therapy and catheter ablation. These therapies have a number of limitations and risks, and have disappointing long-term efficacy in maintaining sinus rhythm and improving hard clinical outcomes. Because of this, there is growing interest in pursuing alternative management strategies in patients with AF. This review seeks to highlight emerging AF therapies, with a specific focus on several modalities aimed at modulation of the autonomic nervous system. These therapies have shown promise in early pre-clinical and clinical trials, and represent exciting alternatives to standard AF treatment.
Topics: Animals; Atrial Fibrillation; Autonomic Nervous System; Baroreflex; Heart Atria; Heart Rate; Humans; Kidney; Magnetic Field Therapy; Pressoreceptors; Recovery of Function; Renal Artery; Sympathectomy; Treatment Outcome; Vagus Nerve Stimulation
PubMed: 31708408
DOI: 10.1016/j.tcm.2019.10.009 -
The Canadian Journal of Cardiology May 2020The sympathetic nervous system plays a pivotal role in the long-term regulation of arterial blood pressure through the ability of the central nervous system to integrate... (Review)
Review
The sympathetic nervous system plays a pivotal role in the long-term regulation of arterial blood pressure through the ability of the central nervous system to integrate neurohumoral signals and differentially regulate sympathetic neural input to specific end organs. Part 1 of this review will discuss neural mechanisms of salt-sensitive hypertension, obesity-induced hypertension, and the ability of prior experiences to sensitize autonomic networks. Part 2 of this review focuses on new therapeutic advances to treat resistant hypertension including renal denervation and carotid baroactivation. Both advances lower arterial blood pressure by reducing sympathetic outflow. We discuss potential mechanisms and areas of future investigation to target the sympathetic nervous system.
Topics: Animals; Autonomic Pathways; Baroreflex; Humans; Hypertension; Kidney; Obesity; Pressoreceptors; Sodium, Dietary; Sympathectomy; Sympathetic Nervous System
PubMed: 32389344
DOI: 10.1016/j.cjca.2020.03.003 -
Cell Reports Nov 2019Soohong et al. (2019) reveal a class of vagal afferents-defined by Piezo2 expression-that innervate the aorta and function to sense blood pressure fluctuations. Their...
Soohong et al. (2019) reveal a class of vagal afferents-defined by Piezo2 expression-that innervate the aorta and function to sense blood pressure fluctuations. Their study describes the morphologies and role of these neurons in vascular regulation.
Topics: Animals; Aorta; Baroreflex; Blood Pressure; Hoof and Claw; Pressoreceptors
PubMed: 31747586
DOI: 10.1016/j.celrep.2019.11.031 -
American Journal of Physiology.... Nov 2023The purpose of these experiments was to determine if the increase in vascular conductance following a single muscle contraction (50% of maximal voluntary contraction) (6...
The purpose of these experiments was to determine if the increase in vascular conductance following a single muscle contraction (50% of maximal voluntary contraction) (6 male and 6 female subjects) was altered during baroceptor loading and unloading. Rapid onset vasodilation (ROV) was determined by measuring brachial artery blood flow (Doppler ultrasound) and blood pressure (Finapress monitor). Brachial artery vascular conductance was calculated by dividing blood flow by mean arterial pressure. ROV was described by the area under the Δvascular conductance (VC)-time curve during the 30 s following muscle contraction. ROV was determined using chamber pressures of +20, +10, 0, -10, -20, and -40 mmHg (lower body positive and negative pressure, LBPP, and LBNP). We tested the hypothesis that the impact of baroreceptor loading and unloading produces a proportion change in ROV. The level of ROV following each contraction was proportional to the peak force ( = 0.393, = 0.0001). Peak force was therefore used as a covariate in further analysis. ROV during application of -40 mmHg LBNP (0.345 ± 0.229 mL·mmHg) was lower than that observed at Control (0.532 ± 0.284 mL·mmHg, = 0.034) and +20 mmHg LBPP (0.658 ± 0.364 mL·mmHg, = 0.0008). ROV was linearly related to chamber pressure from -40 to +20 mmHg chamber pressure ( = 0.512, = 0.022, = 69) and from -20 to +10 mmHg chamber pressure (= 0.973, < 0.0425, = 45), Overall, vasoconstrictor tone altered with physiologically relevant baroreceptor loading and unloading resulted in a proportion change in ROV. Rapid onset vasodilation (ROV) was linearly related to the peak force of each single 1-s muscle contraction. In addition, ROV is reduced by baroreceptor unloading (LBNP: -10, -120, and -40 mmHg) and increased by baroreceptor loading (LBPP: +10 and +20 mmHg). Without accounting for peak force and the level of baroreceptor engagement makes comparison of ROV in subjects of differing muscle size or strength untenable.
Topics: Humans; Male; Female; Pressoreceptors; Vasodilation; Hemodynamics; Blood Pressure; Lower Body Negative Pressure; Heart Rate
PubMed: 37694334
DOI: 10.1152/ajpregu.00116.2023 -
Autonomic Neuroscience : Basic &... Sep 2022A reciprocal relationship between the baroreflex and cerebral autoregulation (CA) has been demonstrated at rest and in response to acute hypotension. We hypothesized... (Review)
Review
A reciprocal relationship between the baroreflex and cerebral autoregulation (CA) has been demonstrated at rest and in response to acute hypotension. We hypothesized that the reciprocal relationship between cardiac baroreflex sensitivity (BRS) and CA would be maintained during sustained central hypovolemia induced by lower body negative pressure (LBNP), and that the strength of this relationship would be greater in subjects with higher tolerance to this stress. Healthy young adults (n = 51; 23F/28M) completed a LBNP protocol to presyncope. Subjects were classified as high tolerant (HT; completion of -60 mmHg LBNP stage, ≥20-min) or low tolerant (LT; did not complete -60 mmHg LBNP stage, <20-min). R-R intervals (RRI), systolic arterial pressure (SAP), mean arterial pressure (MAP), and middle cerebral artery velocity (MCAv) were measured continuously. Cardiac BRS was calculated in the time domain (ΔHR/ΔSAP) and frequency domain (RRI-SAP low frequency (LF) transfer function gain), and CA was calculated in the time domain (ΔMCAv/ΔMAP) and frequency domain (MAP-mean MCAv LF transfer function gain). There was a moderate relationship between cardiac BRS and CA for the group of 51 subjects in both the time (R = -0.54, P < 0.0001) and frequency (R = 0.61, P < 0.001) domains; there was a stronger relationship in the HT group (R = 0.73) compared to the LT group (R = 0.31) in the frequency domain (P = 0.08), but no difference between groups in the time domain (HT: R = -0.73 vs. LT: R = -0.63; P = 0.27). These findings suggest that an interaction between BRS and CA may be an important compensatory mechanism that contributes to tolerance to simulated hemorrhage in young healthy adults.
Topics: Blood Pressure; Heart Rate; Hemorrhage; Homeostasis; Humans; Lower Body Negative Pressure; Pressoreceptors; Young Adult
PubMed: 35716525
DOI: 10.1016/j.autneu.2022.103007 -
Circulation Research Jul 2021
Topics: Blood Pressure; Kidney; Pressoreceptors; Renin
PubMed: 34236885
DOI: 10.1161/CIRCRESAHA.121.319559 -
Kidney360 Dec 2022Heart failure is the most common cardiovascular complication of chronic kidney disease (CKD) and foreshadows a high morbidity and mortality rate. Baroreflex impairment...
BACKGROUND
Heart failure is the most common cardiovascular complication of chronic kidney disease (CKD) and foreshadows a high morbidity and mortality rate. Baroreflex impairment likely contributes to cardiovascular mortality. We aimed to study the associations between CKD, heart failure, and baroreflex sensitivity (BRS) and their association with cardiovascular outcomes.
METHODS
We retrospectively analyzed data from a cohort of 247 individuals with moderate to severe HF. All subjects underwent BRS measurements after intravenous phenylephrine along with electrocardiography, echocardiography, and laboratory measurements. We used logistic regression models to assess the association of CKD (estimated glomerular filtration rate <60 ml/min per 1.73 m) with BRS using iterative models. Cox proportional hazards models were used to assess associations of binary BRS and subgroups according to categorizations of CKD and BRS with cardiovascular mortality.
RESULTS
Median eGFR among individuals with CKD was 52 (IQR 44-56) ml/min per 1.73 m. eGFR was lower in those with depressed BRS (65 [IQR 54-76] ml/min per 1.73 m) compared with those with preserved BRS (73 [IQR 64-87] ml/min per 1.73 m; ≤0.001). The majority of individuals with CKD had depressed BRS compared with those without CKD (60% versus 29%; =0.05). In regression models, CKD and BRS were independently associated. Cardiovascular mortality was significantly increased in individuals with or without CKD and depressed BRS compared with those with preserved BRS and CKD.
CONCLUSIONS
Cardiac BRS is depressed in patients with mild to moderate CKD and HF and associated with cardiovascular mortality. Additional study to confirm its contribution to cardiovascular mortality, particularly in advanced CKD, is warranted.
Topics: Humans; Pressoreceptors; Retrospective Studies; Heart Failure; Kidney; Renal Insufficiency, Chronic
PubMed: 36591344
DOI: 10.34067/KID.0004812022