Several phosphate transport processes are present in vascular smooth muscle cells.
bas V Abstract We have studied Pi handling in rat aortic vascular smooth muscle cells (VSMC) using 32P-radiotracer assays. Our results have revealed a complex set of mechanisms consisting in 1) well-known PiT1/PiT2-mediated sodium-dependent Pi transport; 2) Slc20-unrelated sodium-dependent Pi transport that is sensitive to the stilbene derivatives 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) and (4-acetamido-4-isothiocyanostilbene-2,2-disulfonate) (SITS); 3) a sodium-independent Pi uptake system that is competitively inhibited by sulfate, bicarbonate, and arsenate and is weakly inhibited by DIDS, SIT...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 29, 2019 Category: Physiology Authors: Hortells L, Guillén N, Sosa C, Sorribas V Tags: Am J Physiol Heart Circ Physiol Source Type: research

Age-dependent changes in electrophysiology and calcium handling - implications for pediatric cardiac research.
Abstract Rodent models are frequently employed in cardiovascular research, yet our understanding of pediatric cardiac physiology has largely been deduced from more simplified two-dimensional cell studies. Previous studies have shown that postnatal development includes an alteration in the expression of genes and proteins involved in cell coupling, ion channels, and intracellular calcium handling. Accordingly, we hypothesized that postnatal cell maturation is likely to lead to dynamic alterations in whole-heart electrophysiology and calcium handling. To test this hypothesis, we employed multiparametric imaging and ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 29, 2019 Category: Physiology Authors: Swift L, Burke M, Guerrelli D, Reilly M, Ramadan M, McCullough D, Prudencio T, Mulvany C, Chaluvadi A, Jaimes R, Posnack NG Tags: Am J Physiol Heart Circ Physiol Source Type: research

Changes in left and right ventricular longitudinal function after pulmonary valve replacement in patients with Tetralogy of Fallot.
lsson M Abstract Timing and indication for pulmonary valve replacement (PVR) in patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) are uncertain. To improve understanding of pumping mechanics, we investigated atrioventricular coupling before and after surgical PVR. Cardiovascular magnetic resonance (CMR) were performed in patients (n=12) with rToF and PR>35% before and after PVR and in healthy controls (n=15). Atrioventricular plane displacement (AVPD), global longitudinal peak systolic strain (GLS), atrial and ventricular volumes and caval blood flows were analysed. Right ventri...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 29, 2019 Category: Physiology Authors: Sjöberg P, Ostenfeld E, Hedström E, Arheden H, Gustafsson R, Nozohoor S, Carlsson M Tags: Am J Physiol Heart Circ Physiol Source Type: research

LncRNA TUG1 mediates ischemic myocardial injury by targeting miR-132-3p/HDAC3 axis.
CONCLUSIONS: The TUG1/miR-132-3p/HDAC3 axis critically regulates ROS production and the pathogenic development of AMI. Targeting TUG1, up-regulating miR-132-3p, or inhibiting HDAC3 may benefit AMI treatment. PMID: 31858814 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 19, 2019 Category: Physiology Authors: Su Q, Liu Y, Lv XW, Dai RX, Yang XH, Kong BH Tags: Am J Physiol Heart Circ Physiol Source Type: research

Novel Measures of Left Ventricular Electromechanical Discoordination Predict Clinical Outcomes in Children with Pulmonary Arterial Hypertension.
JC Abstract Adverse ventricle-ventricle interaction and resultant LV dysfunction are a recognized pathophysiologic component of disease progression in pulmonary arterial hypertension (PAH) and can be associated with electrical and mechanical dyssynchrony. The purpose of this study was to investigate the clinical and mechanistic implications of LV electro-mechanical dyssynchrony in children with PAH using novel systolic stretch and diastolic relaxation discoordination indices derived non-invasively from CMR. In children with PAH referred for CMR (n=64) and healthy controls (n=20), we calculated two novel markers o...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 19, 2019 Category: Physiology Authors: Frank B, Schäfer M, Douwes JM, Ivy DD, Abman SH, Davidson JA, Burzlaff S, Mitchell MB, Morgan GJ, Browne L, Barker AJ, Truong U, Von Alvensleben JC Tags: Am J Physiol Heart Circ Physiol Source Type: research

Assessing Right Atrial Function in Pulmonary Hypertension -a Window to the Soul of the Right Heart? Editorial Focus on H-00485-2019R2.
PMID: 31858830 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 19, 2019 Category: Physiology Authors: Alenezi F, Rajagopal S, Kutty S Tags: Am J Physiol Heart Circ Physiol Source Type: research

Krogh's capillary recruitment hypothesis, 100 years on: Is the opening of previously closed capillaries necessary to ensure muscle oxygenation during exercise?
ard L Abstract In 1919, August Krogh published his seminal work on skeletal muscle oxygenation. Krogh's observations indicated that muscle capillary diameter is actively regulated, rather than a passive result of arterial blood flow regulation. Indeed, combining a mathematical model with the number of ink-filled capillaries he observed in muscle cross-sections taken at different workloads, Krogh was able to account for muscle tissue's remarkably efficient oxygen extraction during exercise in terms of passive diffusion from nearby capillaries. Krogh was awarded the 1920 Nobel Prize for his account of muscle oxygena...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Angleys H, Østergaard L Tags: Am J Physiol Heart Circ Physiol Source Type: research

A mathematical model for β1-adrenergic regulation of the mouse ventricular myocyte contraction.
A mathematical model for β1-adrenergic regulation of the mouse ventricular myocyte contraction. Am J Physiol Heart Circ Physiol. 2019 Dec 13;: Authors: Mullins PD, Bondarenko VE Abstract The β1-adrenergic regulation of cardiac myocyte contraction plays an important role in regulating heart function. Activation of this system leads to an increased heart rate and stronger myocyte contraction. However, chronic stimulation of the β1-adrenergic signaling system can lead to cardiac hypertrophy and heart failure. To understand the mechanisms of action of β1-adrenoceptors, a mathematical m...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Mullins PD, Bondarenko VE Tags: Am J Physiol Heart Circ Physiol Source Type: research

ADAM12 Controls a Hypertrophic Response in the Heart through the Distinct Descending Pathways.
PMID: 31834835 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Nakayama Y, Yoshioka J Tags: Am J Physiol Heart Circ Physiol Source Type: research

Exacerbated pressor and sympatho-excitatory effects of central Elabela in spontaneously hypertensive rats.
In conclusion, ELA-21 in PVN induces exacerbated pressor and sympatho-excitatory effects in hypertensive rats via PI3K-Akt pathway. PMID: 31834836 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Geng Z, Ye C, Tong Y, Zhang F, Zhou YB, Xiong XQ Tags: Am J Physiol Heart Circ Physiol Source Type: research

β3 adrenergic receptor blockade reduces mortality in endotoxin-induced heart failure by suppressing induced nitric oxide synthase and saving cardiac metabolism.
In this study, we investigated the role of β3AR in sepsis-related myocardial dysfunction using lipopolysaccharide (LPS)-induced endotoxemia as a model of cardiac dysfunction. We placed mice into three treatment groups and treated each with intraperitoneal injections of the β3AR agonist CL316243 (CL group), the β3AR antagonist SR59230A (SR group), or normal saline (NS group). Survival rates were significantly improved in the SR group compared with the other treatment groups. Echocardiography analyses revealed cardiac dysfunction within 6-12 h of LPS injections, but the outcome was significantly better for the...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Kawaguchi S, Okada M, Ijiri E, Koga D, Watanabe T, Hayashi K, Kashiwagi Y, Fujita S, Hasebe N Tags: Am J Physiol Heart Circ Physiol Source Type: research

Physical and Functional Interaction Sites in Cytoplasmic Domains of KCNQ1 and KCNE1 Channel Subunits.
Abstract The cardiac potassium IKs current is carried by a channel complex formed from a-subunits encoded by KCNQ1 and b-subunits encoded by KCNE1. Deleterious mutations in either gene are associated with hereditary long QT syndrome. Interactions between the transmembrane domains of the a- and b-subunits determine the activation kinetics of IKs. A physical and functional interaction between C-termini of the proteins has also been identified that impacts deactivation rate and voltage-dependence of activation. We sought to explore the specific physical interactions between the C-termini of the subunits that confer s...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Chen J, Liu Z, Creagh JP, Zheng R, McDonald TV Tags: Am J Physiol Heart Circ Physiol Source Type: research

Decreased Uterine Vascularization and Uterine Arterial Expansive Remodeling with Reduced Matrix Metalloproteinase-2 and -9 in Hypertensive Pregnancy.
Abstract Preeclampsia is a pregnancy-related disorder characterized by hypertension-in-pregnancy (HTN-Preg), and inadequate trophoblast invasion of the uterine wall could be initiating events. We hypothesized that HTN-Preg involves decreased uterine vascularization and arterial remodeling by MMPs, and accumulation of collagen. Blood pressure (BP) and fetal parameters were assessed in normal Preg rats and Preg rats with reduced uterine perfusion pressure (RUPP), and uterine vascularity, MMP levels and collagen deposition were measured. BP was higher, and the uterus weight, litter size, and pup weight were reduced i...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Lin C, He H, Cui N, Ren Z, Zhu M, Khalil RA Tags: Am J Physiol Heart Circ Physiol Source Type: research

Ranolazine May Exert its Beneficial Effects by Increasing Myocardial Adenosine Levels.
Abstract We hypothesized that ranolazine-induced adenosine release is responsible for its beneficial effects in ischemic heart disease. Sixteen open-chest anesthetized dogs with non-critical coronary stenosis were studied at rest, during dobutamine stress, and during dobutamine stress with ranolazine. Six additional dogs without stenosis were studied only at rest. Regional myocardial function and perfusion were assessed. Coronary venous blood was measured. Murine endothelial cells and cardiomyocytes were incubated with ranolazine and adenosine metabolic enzyme inhibitors, and adenosine levels were measured. Cardio...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 12, 2019 Category: Physiology Authors: Le DE, Davis CM, Wei K, Zhao Y, Cao Z, Nugent M, Scott KL, Liu L, Nagarajan S, Alkayed NJ, Kaul S Tags: Am J Physiol Heart Circ Physiol Source Type: research

Relationship of a thinned medial layer to the attenuated contractile response in atherosclerotic coronary arteries.
This study aimed to clarify the relationship between thickness of the medial layer and the contractile response to acetylcholine (ACh) in coronary artery using optical coherence tomography (OCT). Methods and Results: The OCT and the vasomotor response to ACh in the left anterior descending coronary artery were assessed in 32 patients with previous myocardial infarction. The intimal and medial layer areas were measured by planimetric analysis of the OCT images. The coronary contractile response to ACh had a positive linear relationship with medial area (r = 0.61, P
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 5, 2019 Category: Physiology Authors: Nakamura T, Horikoshi T, Kugiyama K Tags: Am J Physiol Heart Circ Physiol Source Type: research

Antenatal sildenafil citrate treatment increases offspring blood pressure in the placental-specific Igf2 knockout mouse model of FGR.
This study aimed to assess the effect of antenatal SC treatment on metabolic and cardiovascular health in offspring by assessing postnatal weight gain, glucose tolerance, systolic blood pressure and resistance artery function in a mouse model of FGR, the placental-specific insulin-like growth factor 2 (PO) knockout mouse. SC was administered subcutaneously (10 mg.kg-1) daily from embryonic day (E)12.5. Antenatal SC treatment did not alter fetal weight or viability but increased postnatal weight gain in WT female offspring (P
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 5, 2019 Category: Physiology Authors: Renshall LJ, Cottrell EC, Cowley E, Sibley CP, Baker PN, Thorstensen E, Greenwood SL, Wareing M, Dilworth MR Tags: Am J Physiol Heart Circ Physiol Source Type: research

Potential roles in cardiac physiology and pathology of the cation channel TRPV2 expressed in cardiac cells and cardiac macrophages: a mini-review.
Abstract TRPV2 is a well-conserved channel protein expressed in almost all tissues. Cardiomyocyte TRPV2 is expressed in the intercalated discs of the cardiac sarcomeres where it is involved in maintaining the proper mechanoelectric coupling and structure. It is also abundantly expressed in the intracellular pools, mainly the endoplasmic reticulum. Under pathological conditions, TRPV2 is translocated to the sarcolemma where it mediates an abnormal [Ca]2+ entry that may contribute to disease progression. In addition, an intracellularly diffused TRPV2 expression is present in resident cardiac macrophages. Upon infect...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 5, 2019 Category: Physiology Authors: Entin-Meer M, Keren G Tags: Am J Physiol Heart Circ Physiol Source Type: research

Monocytes Prime Autoreactive T cells After Myocardial Infarction.
Abstract In humans, loss of central tolerance for the cardiac self-antigen, α-myosin heavy chain (αMyHC), leads to circulation of cardiac autoreactive T cells and renders the heart susceptible to autoimmune attack after acute myocardial infarction (MI). MI triggers profound tissue damage, releasing danger signals and self-antigen by necrotic cardiomyocytes, which leads to recruitment of inflammatory monocytes. We hypothesized that excessive inflammation by monocytes contribute to the initiation of adaptive immune responses to cardiac self-antigen. Using an experimental model of MI in mice, αMHC-m...
Source: American Journal of Physiology. Heart and Circulatory Physiology - December 5, 2019 Category: Physiology Authors: DeBerge MP, Yu S, Dehn S, Ifergan I, Yeap XY, Filipp M, Becker A, Luo X, Miller SD, Thorp EB Tags: Am J Physiol Heart Circ Physiol Source Type: research

Letter to Editor: Aortic distensibility and coronary blood flow: does cardiac period play a role?
PMID: 31797696 [PubMed - in process] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 30, 2019 Category: Physiology Authors: Papaioannou TG, Vavuranakis M, Tousoulis D Tags: Am J Physiol Heart Circ Physiol Source Type: research

Reply to "Letter to the Editor: Aortic distensibility and coronary blood flow: does cardiac period play a role?"
Reply to "Letter to the Editor: Aortic distensibility and coronary blood flow: does cardiac period play a role?" Am J Physiol Heart Circ Physiol. 2019 Dec 01;317(6):H1389 Authors: Nelson AJ, Worthley MI PMID: 31797697 [PubMed - in process] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 30, 2019 Category: Physiology Authors: Nelson AJ, Worthley MI Tags: Am J Physiol Heart Circ Physiol Source Type: research

Corrigendum.
Authors: PMID: 31797698 [PubMed - in process] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 30, 2019 Category: Physiology Tags: Am J Physiol Heart Circ Physiol Source Type: research

A Disintegrin and Metalloproteinase 12 prevents heart failure by regulating cardiac hypertrophy and fibrosis.
Abstract A disintegrin and metalloproteinase (ADAM) 12 is considered to promote cardiac dysfunction based on the finding that a small molecule ADAM12 inhibitor, KB-R7785 ameliorated cardiac function in a transverse aortic constriction (TAC) model by inhibiting the proteolytic activation of HB-EGF signaling. However, this compound has poor selectivity for ADAM12, and the role of ADAM12 in cardiac dysfunction has not yet been investigated using genetic loss-of-function mice. We revealed that ADAM12 knockout mice showed significantly more advanced cardiac hypertrophy and higher mortality rates than wild-type mice 4 w...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Nakamura Y, Kita S, Tanaka Y, Fukuda S, Obata Y, Okita T, Kawachi Y, Tsugawa-Shimizu Y, Fujishima Y, Nishizawa H, Miyagawa S, Sawa Y, Sehara-Fujisawa A, Maeda N, Shimomura I Tags: Am J Physiol Heart Circ Physiol Source Type: research

Spinal cord injury alters purinergic neurotransmission to mesenteric arteries in rats.
Abstract Complications associated with spinal cord injury (SCI) result from unregulated reflexes below the lesion level. Understanding neurotransmission distal to the SCI could improve quality of life by mitigating complications. The long-term impact of SCI on neurovascular transmission is poorly understood but reduced sympathetic activity below the site of SCI enhances arterial neurotransmission (1). We studied sympathetic neurovascular transmission using a rat model of long-term paraplegia (T2-3) and tetraplegia (C6-7). Sixteen weeks after SCI, T2-3 and C6-7 rats had lower blood pressure (BP) than sham rats (103...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Sangsiri S, Xu H, Fernandes R, Fink GD, Lujan HL, DiCarlo SE, Galligan JJ Tags: Am J Physiol Heart Circ Physiol Source Type: research

Regional right ventricular function in rats: a novel magnetic resonance imaging method for measurement of right ventricular strain.
tad I Abstract The function of the RV is linked to clinical outcome in many cardiovascular diseases, but its role in experimental heart failure remains largely unexplored due to difficulties in measuring RV function in vivo. We aimed to advance RV imaging by establishing phase contrast MRI (PC-MRI) as a robust method for measuring RV function in rodents. 46 Wistar-Hannover rats with left ventricular (LV) myocardial infarction and 10 control rats (sham) were examined six weeks after surgery. Using a 9.4T preclinical MRI system, we utilized PC-MRI to measure strain/strain-rate in the RV free-wall under isoflurane an...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Espe EKS, Aronsen JM, Nordén ES, Zhang L, Sjaastad I Tags: Am J Physiol Heart Circ Physiol Source Type: research

Improved endothelial-dependent and endothelial-independent skin vasodilator responses following remote ischemic preconditioning.
Abstract INTRODUCTION: One week of daily remote ischemic preconditioning (RIPC) improves cutaneous vasodilatory (VD) function. However, the underlying mechanisms and the number of sessions needed to optimize this adaptive response remain unclear. We hypothesized that the responses to localized heating of the skin will be greater after 2 weeks as opposed to 1 week of RIPC. Furthermore, 2 weeks of repeated RIPC will augment cutaneous VD responses to thermal and pharmacological stimuli. METHODS: Twenty-four participants (24±2 years; 13 males, 11 females) performed repeated RIPC (7 daily sessions over 1 we...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Kim J, Franke WD, Lang JA Tags: Am J Physiol Heart Circ Physiol Source Type: research

The Implementation of Physiological Afterload during Ex Situ Heart Perfusion Augments Prediction of Post-Transplant Function.
Abstract Ex Situ heart perfusion (ESHP) is an emerging technique that aims to increase the number of organs available for transplantation by augmenting both donor heart preservation and evaluation. Traditionally, ESHP has been performed in an unloaded Langendorff Mode (LM), though more recently groups have begun to use Pump Supported Working Mode (PSWM) and Passive Afterload Working Mode (PAWM) to enable contractile evaluation during ESHP. To this point, however, neither the predictive effectiveness of the two working modes, nor the predictive power of individual contractile parameters have been analyzed. In this ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Gellner B, Xin L, Ribeiro RV, Bissoondath V, Adamson MB, Yu F, Lu P, Paradiso E, Mbadjeu A, Simmons CA, Badiwala MV Tags: Am J Physiol Heart Circ Physiol Source Type: research

MCP-1 mediates ischemia/reperfusion-induced cardiomyocyte apoptosis via MCPIP1 and CaSR.
CONCLUSIONS: Based on these findings, I/R-induced MCP-1 release regulates cardiomyocyte apoptosis via the MCPIP1 and CaSR pathways, suggesting a new therapeutic strategy for I/R injury. PMID: 31774703 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 26, 2019 Category: Physiology Authors: Zhang W, Zhu T, Chen L, Luo W, Chao J Tags: Am J Physiol Heart Circ Physiol Source Type: research

Right ventricular function correlates of right atrial strain in pulmonary hypertension: a combined cardiac magnetic resonance and conductance catheter study.
Abstract The functional relevance of right atrial (RA) function in pulmonary hypertension (PH) remains incompletely understood. The purpose of this study was to explore the correlation of cardiac magnetic resonance (CMR) feature tracking-derived RA phasic function with invasively measured pressure-volume (PV) loop-derived right ventricular (RV) end-diastolic elastance (Eed) and RV-arterial coupling [end-systolic/arterial elastance (Ea/Ees)]. In 54 patients with severe PH, CMR was performed within 24 hours of diagnostic right heart catheterization and PV measurements. RA phasic function was assessed by CMR imaging ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 21, 2019 Category: Physiology Authors: Tello K, Dalmer A, Vanderpool RR, Ghofrani HA, Naeije R, Roller F, Seeger W, Wiegand M, Gall H, Richter MJ Tags: Am J Physiol Heart Circ Physiol Source Type: research

Early Onset Neurocirculatory Response to Static Handgrip is Associated with Greater Blood Pressure Variability in Women with Post-Traumatic Stress Disorder.
Abstract Post-traumatic stress disorder (PTSD) is a psychiatric illness that is more prevalent in women and accumulating evidence suggests a link between PTSD and future development of cardiovascular disease. The underlying mechanisms are unclear but augmented sympathetic reactivity to daily stressors may be involved. We measured muscle sympathetic nerve activity (MSNA), blood pressure (BP), and heart rate responses in 14 women with PTSD and 14 healthy women (controls) during static handgrip (SHG) exercise to fatigue at 40% of maximal voluntary contraction (MVC). Two min of post-exercise circulatory arrest (PECA) ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 21, 2019 Category: Physiology Authors: Yoo JK, Badrov MB, Parker RS, Anderson EH, Wiblin JL, Last Name CS, Suris A, Fu Q Tags: Am J Physiol Heart Circ Physiol Source Type: research

The glucagon-like peptide 1 receptor agonist liraglutide attenuates placental-ischemia induced hypertension.
Abstract Preeclampsia is a hypertensive disorder of pregnancy characterized by systemic perturbations of nitric oxide function, reflective of generalized endothelial dysfunction. Therapies that target the nitric oxide pathway have shown promise in both clinical and preclinical studies of preeclampsia. The glucagon-like peptide 1 agonists have been shown to increase nitric oxide and lower blood pressure in patients with diabetes, in part through activation of nitric oxide synthase (NOS). Therefore, we hypothesized that a direct acting glucagon-like peptide 1 receptor agonist would improve stigmata of the preeclamps...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 14, 2019 Category: Physiology Authors: Younes ST, Maeda KJ, Sasser JM, Ryan MJ Tags: Am J Physiol Heart Circ Physiol Source Type: research

Pharmacological blockage of ICAM-1 improves angiotensin II-induced cardiac remodeling by inhibiting adhesion of LFA-1+ monocytes.
In conclusion, these results provide novel evidence that blocking ICAM-1 exerts a protective effect in Ang II-induced cardiac remodeling at least in part through the modulation of adhesion and infiltration of LFA-1+ macrophages in the heart. Inhibition of ICAM-1 may represent a new therapeutic approach for hypertrophic heart diseases. PMID: 31729904 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 14, 2019 Category: Physiology Authors: Lin QY, Lang PP, Zhang YL, Yang X, Xia Y, Bai J, Li HH Tags: Am J Physiol Heart Circ Physiol Source Type: research

Bimodal Right Ventricular Dysfunction After Postnatal Hyperoxia Exposure: Implications for the Preterm Heart.
CONCLUSION: There appears to be a "honeymoon period" where cardiac hemodynamic and mitochondrial function normalizes following postnatal hyperoxia exposure, only to decline again with ongoing aging. This finding may have significant implications if a long-term pulmonary vascular screening program were to be developed for children or adults with a history of severe prematurity. Further investigation into the mechanisms of recovery are warranted. PMID: 31702968 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 7, 2019 Category: Physiology Authors: Kumari S, Braun RK, Tetri L, Barton GP, Hacker TA, Goss KN Tags: Am J Physiol Heart Circ Physiol Source Type: research

Clinical safety of blood flow restricted training? A comprehensive review of altered muscle metaboreflex in cardiovascular disease during ischemic exercise.
nha T Abstract Blood flow restriction training (BFRT) is an increasingly widespread method of exercise that involves imposed restriction of blood flow to the exercising muscle. Blood flow restriction is achieved by inflating a pneumatic pressure cuff (or a tourniquet) positioned proximal to the exercising muscle prior to, and during, the bout of exercise (i.e., ischemic exercise). Low-intensity BFRT with resistance training promotes comparable increases in muscle mass and strength observed during high-intensity exercise without blood flow restriction. BFRT has expanded into the clinical research setting as a poten...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 7, 2019 Category: Physiology Authors: Cristina-Oliveira M, Meireles K, Spranger MD, O'Leary DS, Roschel H, Peçanha T Tags: Am J Physiol Heart Circ Physiol Source Type: research

A Novel Methodology for Rat Aortic Pulse Wave Velocity Assessment by Doppler Ultrasound: Validation against Invasive Measurements.
Abstract There is still lack of a simple, accurate and noninvasive method for rat aortic pulse wave velocity (PWV) measurement, especially the transit distance cannot be accurately measured. Thus we aimed to derive an equation for aortic transit distance as a function of the nose-to-rump length (L), and to test the hypothesis that aortic PWV measured by new equation combined with Doppler ultrasound (the "equation method") may have stronger correlation with invasive measurements than traditional "body surface method". Two hundred male Sprague-Dawley (SD) rats (age ranged 5-24 weeks) were include...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 7, 2019 Category: Physiology Authors: Wang Z, Fu Z, Yang Y, Xing W, Zhang X, Wang J, Li Y, Yuan L, Gao F Tags: Am J Physiol Heart Circ Physiol Source Type: research

Adaptive Immunity Driven Inflammation and Cardiovascular Disease.
Abstract The adaptive immune response has recently emerged as an important factor in a wide variety of cardiovascular disorders including atherosclerosis, hypertension, cardiac remodeling, and heart failure; however, its role is not fully understood. Since an assortment of innate responsive cells (e.g. neutrophils, monocytes/macrophages) coordinate with adaptive immunity (e.g. T-cells, dendritic cells, B-cells), the temporal response and descriptions pertinent to the cellular phenotype, and inflammation processes in general, need additional investigation, clarification, and consensus particularly in cardiovascular...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 7, 2019 Category: Physiology Authors: Ilatovskaya DV, Halade GV, DeLeon-Pennell KY Tags: Am J Physiol Heart Circ Physiol Source Type: research

Disentangling the Gordian knot of local metabolic control of coronary blood flow.
Abstract Recognition that coronary blood flow is tightly coupled with myocardial metabolism has been appreciated for well over half a century. However, exactly how coronary microvascular resistance is tightly coupled with myocardial oxygen consumption (MVO2) remains one of (if not) the most highly contested mysteries of the coronary circulation to this day. Understanding the mechanisms responsible for local metabolic control of coronary blood flow has been confounded by continued debate regarding both anticipated experimental outcomes and data interpretation. For a number of years, coronary venous PO2 has been gen...
Source: American Journal of Physiology. Heart and Circulatory Physiology - November 7, 2019 Category: Physiology Authors: Tune JD, Goodwill AG, Kiel A, Baker HE, Bender SB, Merkus D, Duncker DJ Tags: Am J Physiol Heart Circ Physiol Source Type: research

Computational quantification of patient specific changes in ventricular dynamics associated with pulmonary hypertension.
Abstract Pulmonary arterial hypertension causes an increase in the mechanical loading imposed on the right ventricle that results in progressive changes to its mechanics and function. Here, we quantify the mechanical changes associated with PAH by assimiliating clinical data consisting of reconstructed 3D geometry, pressure and volume waveforms as well as regional strains measured in PAH patients (n = 12) and controls (n = 6) within a computational modeling framework of the ventricles. Modeling parameters reflecting regional passive stiness and load-independent contractility as indexed by the tissue active tension...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Finsberg HNT, Sundnes JS, Xi C, Lee LC, Zhao X, Tan JL, Genet M, Zhong L, Wall ST Tags: Am J Physiol Heart Circ Physiol Source Type: research

Acute reduction in cerebral blood velocity on supine-to-stand transition increases postural instability in young adults.
Abstract We tested the hypothesis that transient deficits in cerebral blood flow are associated with postural sway. In 19 young healthy adults, we examined the association between the drop in cerebral blood flow during supine-to-stand transitions (indexed by transcranial Doppler ultrasound (middle cerebral artery blood velocity at diastole; MCAdv) and near-infrared spectroscopy (tissue saturation index; TSI)) and the center of pressure displacement while standing. Participants performed transitions under 3 conditions aimed at progressively increasing the drop in MCAdv, in a randomized order: (i) a control transiti...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Fitzgibbon-Collins LK, Noguchi M, Heckman GA, Hughson RL, Robertson AD Tags: Am J Physiol Heart Circ Physiol Source Type: research

Cardiac ischemia/reperfusion injury induces ROS-dependent loss of PKA regulatory subunit RI α.
Cardiac ischemia/reperfusion injury induces ROS-dependent loss of PKA regulatory subunit RIα. Am J Physiol Heart Circ Physiol. 2019 Nov 01;: Authors: Haushalter KJ, Schilling JM, Song Y, Sastri M, Perkins GA, Strack S, Taylor SS, Patel HH Abstract Type I PKA regulatory subunit alpha (RIα; encoded by the Prkar1a gene) serves as the predominant inhibitor protein of the catalytic subunit of cAMP-dependent protein kinase (PKAc). However, recent evidence suggests that PKA signaling can be initiated by cAMP-independent events, especially within the context of cellular oxidative stress such as is...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Haushalter KJ, Schilling JM, Song Y, Sastri M, Perkins GA, Strack S, Taylor SS, Patel HH Tags: Am J Physiol Heart Circ Physiol Source Type: research

Hemodynamic effects of myocardial bridging in patients with hypertrophic cardiomyopathy.
Abstract Myocardial bridging (MB) is linked to angina and myocardial ischemia and may lead to sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, it remains unclear how MB affect the coronary blood flow in HCM patients. The aim of this study was to assess the effects of MB on coronary hemodynamics in HCM patients. Fifteen patients with MB (7 HCM and 8 non-HCM controls) in their left anterior descending (LAD) coronary artery were chosen. Transient computational fluid dynamics (CFD) simulations were conducted in anatomically realistic models of diseased (with MB) and virtually healthy (...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Sharzehee M, Chang Y, Song JP, Han HC Tags: Am J Physiol Heart Circ Physiol Source Type: research

Using velocity-pressure loops in the operating room: a new approach of arterial mechanics for cardiac afterload monitoring under general anesthesia.
ée F Abstract Cardiac afterload is usually assessed in the ascending aorta and can be defined by the association of peripheral vascular resistance (PVR), total arterial compliance (Ctot) and aortic wave reflection (WR). We recently proposed the global afterload angle (GALA) and beta angle derived from the aortic velocity-pressure loop (VP loop) as continuous cardiac afterload monitoring in the descending thoracic aorta. The aim of this study was: (1) to describe the arterial mechanic properties by studying the velocity-pressure relations according to cardiovascular risk (Lo-risk and Hi-risk patients) in the...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Hong A, Joachim J, Buxin C, Levé C, Le Gall A, Millasseau S, Mateo J, Civelli V, Serrano J, Mebazaa A, Gayat E, Vallée F Tags: Am J Physiol Heart Circ Physiol Source Type: research

ASIC1a plays a key role in evoking the metabolic component of the exercise pressor reflex in rats.
Abstract The role of the acid-sensing ion channel 1a (ASIC1a) in evoking the exercise pressor reflex is unknown despite the fact that ASIC1a is opened by decreases in pH in the physiological range. This fact prompted us to test the hypothesis that ASIC1a plays an important role in evoking the exercise pressor reflex in decerebrated rats with freely perfused hindlimb muscles. To test this hypothesis, we measured the effect of injecting two ASIC1a blockers into the arterial supply of the triceps surae muscles on the reflex pressor responses to four maneuvers, namely (1) static contraction of the triceps surae muscle...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Ducrocq GP, Kim JS, Estrada JA, Kaufman MP Tags: Am J Physiol Heart Circ Physiol Source Type: research

Caspase Lesions of PVN-Projecting MnPO Neurons Blocks the Sustained Component of CIH-Induced Hypertension in Adult Male Rats.
Abstract Obstructive Sleep Apnea is characterized by interrupted breathing that leads to cardiovascular sequelae including chronic hypertension that can persist into waking hours. Chronic intermittent hypoxia, which models the hypoxemia associated with sleep apnea, is sufficient to cause a sustained increase in blood pressure that involves the central nervous system. The median preoptic nucleus (MnPO) is an integrative forebrain region that contributes to blood pressure regulation and neurogenic hypertension. The MnPO projects to the paraventricular nucleus (PVN), a pre-autonomic region. We hypothesized that pathw...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Marciante AB, Wang LA, Little JT, Cunningham JT Tags: Am J Physiol Heart Circ Physiol Source Type: research

Sympathetic baroreflex sensitivity is inversely related to vascular transduction in males but not females.
In this study we tested the hypothesis that there is an inverse relationship between sympathetic BRS and vascular transduction. In 38 (18 males) healthy adults, continuous measurements of blood pressure, MSNA and superficial femoral artery diameter and blood flow (Doppler ultrasound) were recorded during 10 min of rest. Spontaneous sympathetic BRS was quantified as the relationship between diastolic pressure and MSNA burst incidence. Vascular transduction was quantified by plotting the changes in leg vascular conductance for 10 cardiac cycles following each burst of MSNA, and taking the nadir. In males, sympathetic BRS was...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 31, 2019 Category: Physiology Authors: Hissen SL, Macefield VG, Brown R, Taylor CE Tags: Am J Physiol Heart Circ Physiol Source Type: research

Editorial Focus - Venous Return: A Fresh Start.
PMID: 31651182 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 24, 2019 Category: Physiology Authors: Dalmau R Tags: Am J Physiol Heart Circ Physiol Source Type: research

Hydrogen Sulfide Regulation of Renal and Mesenteric Blood Flow.
Abstract Hydrogen sulfide (H2S) dilates isolated arteries and knockout of the H2S synthesizing enzyme, cystathionine γ-lyase (CSE), increases blood pressure. However, the contributions of endogenously produced H2S to blood flow regulation in specific vascular beds is unknown. Published studies in isolated arteries show that CSE production of H2S influences vascular tone more in small mesenteric arteries than in renal arteries or the aorta. Therefore, the goal of this study was to evaluate H2S regulation of blood pressure, vascular resistance and regional blood flows using chronically instrumented rats. We hy...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 17, 2019 Category: Physiology Authors: Morales-Loredo H, Barrera A, Garcia J, Pace CE, Naik JS, Gonzalez-Bosc LV, Kanagy NL Tags: Am J Physiol Heart Circ Physiol Source Type: research

Deletion of the microRNA-degrading nuclease, translin/trax, prevents pathogenic vascular stiffness.
Abstract Vascular stiffness plays a key role in the pathogenesis of hypertension. Recent studies indicatethat the age associated reduction in miR-181b levels in vascular smooth muscle cells (VSMCs)contributes to increased vascular stiffness. As these findings suggest that inhibiting degradation of miR-181b might prevent vascular stiffening, we have assessed whether themicroRNA-degrading translin/trax (TN/TX) complex mediates degradation of miR-181b in the aorta.We found that TN-/- mice display elevated levels of miR-181b expression in the aorta. Therefore, we tested if TN deletion prevents vascular stiffening in a...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 17, 2019 Category: Physiology Authors: Tuday E, Nomura Y, Ruhela D, Nakano M, Fu X, Shah A, Roman B, Yamaguchi A, An SS, Steenbergen C, Baraban JM, Berkowitz DE, Das S Tags: Am J Physiol Heart Circ Physiol Source Type: research

Increased arrhythmia susceptibility in type 2 diabetic mice related to dysregulation of ventricular sympathetic innervation.
CONCLUSION: Collectively, these findings suggest that the increased ventricular arrhythmia susceptibility of type 2 diabetic mouse hearts is due to dysregulation of the sympathetic ventricular control. PMID: 31625779 [PubMed - as supplied by publisher] (Source: American Journal of Physiology. Heart and Circulatory Physiology)
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 17, 2019 Category: Physiology Authors: Jungen C, Scherschel K, Flenner F, Jee H, Rajendran PS, De Jong KA, Nikolaev VO, Meyer C, Ardell JL, Tompkins JD Tags: Am J Physiol Heart Circ Physiol Source Type: research

Increased Myocyte Calcium Sensitivity in End-Stage Pediatric Dilated Cardiomyopathy.
Abstract Dilated cardiomyopathy (DCM) is the most common cause of heart failure (HF) in children, resulting in high mortality and need for heart transplantation. The pathophysiology underlying pediatric DCM is largely unclear, however there is emerging evidence that molecular adaptations and response to conventional HF medications differ between children and adults. In order to gain insight into alterations leading to systolic dysfunction in pediatric DCM, we measured cardiomyocyte contractile properties and sarcomeric protein phosphorylation in explanted pediatric DCM myocardium (N=8) compared to non-failing (NF)...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 17, 2019 Category: Physiology Authors: Nakano SJ, Walker JS, Walker LA, Li X, Du Y, Miyamoto SD, Sucharov CC, Garcia AM, Mitchell MB, Ambardekar AV, Stauffer BL Tags: Am J Physiol Heart Circ Physiol Source Type: research

Maternal microbiome and the hypertensive disorder of pregnancy, preeclampsia.
Abstract Preeclampsia (PE) is a pregnancy specific disorder that can be life threatening for both mother and baby. It is characterized by new onset hypertension during the second half of pregnancy and affects approximately 300,000 women in the United States every year. There is no cure for PE and the only effective treatment is delivery of the placenta and the fetus, which is often preterm. PE is believed to be a severe manifestation of placental dysfunction due to early angiogenic imbalances and inflammatory disturbances; however, the cause of this is unknown. The once thought "sterile" placenta now has...
Source: American Journal of Physiology. Heart and Circulatory Physiology - October 17, 2019 Category: Physiology Authors: Beckers KF, Sones JL Tags: Am J Physiol Heart Circ Physiol Source Type: research