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vasodilation and exercise

Flavio Pereira, Roger de Moraes, Diogo Van Bavel, Andrea De Lorenzo, Eduardo Tibirica
Introduction: The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density. Materials and Methods: Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH)...
March 14, 2018: Military Medicine
Thenappan Thenappan, Mark L Ormiston, John J Ryan, Stephen L Archer
Pulmonary hypertension is defined as a resting mean pulmonary artery pressure of 25 mm Hg or above. This review deals with pulmonary arterial hypertension (PAH), a type of pulmonary hypertension that primarily affects the pulmonary vasculature. In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening. Many cell types are abnormal in PAH, including vascular cells (endothelial cells, smooth muscle cells, and fibroblasts) and inflammatory cells...
March 14, 2018: BMJ: British Medical Journal
Carlos D Davila, James E Udelson
Among all patients referred for stress myocardial perfusion imaging (MPI), a substantial proportion in contemporary practice cannot exercise. Another group of patients are those who are thought to be able to achieve an adequate workload with treadmill (or bicycle) exercise but do not achieve at least 85% of maximum predicted heart rate without developing symptoms. There has been substantial interest and literature on the adjunctive use of vasodilator stress during the same visit to generate best-quality results for patients who do not exercise adequately...
March 2018: JACC. Cardiovascular Imaging
Stuart D Katz
Heart failure is a common form of heart disease associated with progressive exercise intolerance and high risk of adverse clinical outcome events. The pathophysiology of chronic systolic heart failure is fundamentally determined by the failure of the circulatory system to deliver oxygen sufficient for metabolic needs, and it is best explained by a complex interplay between intrinsic abnormalities of ventricular pump function and extracardiac factors that limit oxygen use in metabolically active tissues. This brief review highlights the role of extracardiac factors (peripheral factors) that may impact exercise capacity in patients with chronic systolic heart failure...
February 2018: Annals of the American Thoracic Society
Mária Szekeres, György L Nádasy, Gabriella Dörnyei, Annamária Szénási, Akos Koller
PURPOSE: Exercise elicits early adaptation of coronary vessels enabling the coronary circulation to respond adequately to higher flow demands. We hypothesized that short-term daily exercise induces biomechanical and functional remodeling of the coronary resistance arteries related to pressure. METHODS: Male rats were subjected to a progressively increasing 4-week treadmill exercise program (over 60 min/day, 1 mph in the final step). In vitro pressure-diameter measurements were performed on coronary segments (119 ± 5 μm in diameter at 50 mm Hg) with microarteriography...
February 14, 2018: Journal of Vascular Research
Robert D Meade, Craig G Crandall, Daniel Gagnon, Glen P Kenny
Following exercise, mean arterial pressure (MAP) is reduced ~5-10 mmHg from pre-exercise baseline. In non-endurance-trained males, post-exercise hypotension results from peripheral vasodilation not offset by increased cardiac output (CO). By contrast, post-exercise hypotension occurs through a reduction in CO from pre-exercise baseline in endurance-trained males. The reason(s) explaining these divergent responses remain unknown. Exercise at fixed percentage of peak oxygen consumption (VO2peak) is associated with a greater rate of metabolic heat production in trained individuals and therefore elevated sweat rates, both when compared to untrained individuals...
February 1, 2018: Journal of Applied Physiology
Matthew K Hensley, Andrea Levine, Mark T Gladwin, Yen-Chun Lai
Pulmonary hypertension (PH) is a progressive and often fatal illness presenting with nonspecific symptoms of dyspnea, lower extremity edema, and exercise intolerance. Pathologically, endothelial dysfunction leads to abnormal intimal and smooth muscle proliferation along with reduced apoptosis, resulting in increased pulmonary vascular resistance (PVR) and elevated pulmonary pressures. PH is subdivided into five WHO groups based on the disease pathology and specific cause. While there are FDA-approved medications for the treatment of pulmonary arterial hypertension (PAH, Group 1 PH), as well as for chronic thromboembolic pulmonary hypertension (CTEPH, Group 4 PH), the morbidity and mortality remain high...
February 1, 2018: American Journal of Physiology. Lung Cellular and Molecular Physiology
Jennifer C Richards, Matthew L Racine, Christopher M Hearon, Megan Kunkel, Gary J Luckasen, Dennis G Larson, Jason D Allen, Frank A Dinenno
Dietary nitrate (NO3-) is converted to nitrite (NO2-) and can be further reduced to the vasodilator nitric oxide (NO) amid a low O2 environment. Accordingly, dietary NO3- increases hind limb blood flow in rats during treadmill exercise; however, the evidence of such an effect in humans is unclear. We tested the hypothesis that acute dietary NO3- (via beetroot [BR] juice) increases forearm blood flow (FBF) via local vasodilation during handgrip exercise in young adults (n = 11; 25 ± 2 years). FBF (Doppler ultrasound) and blood pressure (Finapres) were measured at rest and during graded handgrip exercise at 5%, 15%, and 25% maximal voluntary contraction (MVC) lasting 4 min each...
January 2018: Physiological Reports
Marko Novaković, Katja Prokšelj, Uroš Rajkovič, Tjaša Vižintin Cuderman, Katja Janša Trontelj, Zlatko Fras, Borut Jug
INTRODUCTION: Adults with repaired tetralogy of Fallot (ToF) have impaired exercise capacity, vascular and cardiac autonomic function, and quality of life (QoL). Specific effects of high-intensity interval or moderate continuous exercise training on these parameters in adults with repaired ToF remain unknown. METHODS AND RESULTS: Thirty adults with repaired ToF were randomized to either high-intensity interval, moderate intensity continuous training (36 sessions, 2-3 times a week) or usual care (no supervised exercise)...
January 3, 2018: International Journal of Cardiology
Raúl Domínguez, José Luis Maté-Muñoz, Eduardo Cuenca, Pablo García-Fernández, Fernando Mata-Ordoñez, María Carmen Lozano-Estevan, Pablo Veiga-Herreros, Sandro Fernandes da Silva, Manuel Vicente Garnacho-Castaño
Beetroot juice contains high levels of inorganic nitrate (NO3 - ) and its intake has proved effective at increasing blood nitric oxide (NO) concentrations. Given the effects of NO in promoting vasodilation and blood flow with beneficial impacts on muscle contraction, several studies have detected an ergogenic effect of beetroot juice supplementation on exercise efforts with high oxidative energy metabolism demands. However, only a scarce yet growing number of investigations have sought to assess the effects of this supplement on performance at high-intensity exercise...
2018: Journal of the International Society of Sports Nutrition
Alessia Gimelli, Riccardo Liga, Alberto Clemente, Emilio Maria Pasanisi, Brunella Favilli, Paolo Marzullo
Aims: To evaluate the impact of diabetes mellitus (DM) on the accuracy of myocardial perfusion scintigraphy (MPS) in detecting coronary artery disease (CAD). Methods and results: Two hundred and sixteen patients with DM and 432 matched controls were submitted to MPS on a dedicated cardiac camera equipped with cadmium-zinc-telluride (CZT) detectors and coronary angiography. Exercise stress was performed in 442 (68%) patients, while the remainders underwent vasodilator stress...
December 11, 2017: European Heart Journal Cardiovascular Imaging
Joshua T Butcher, M Irfan Ali, Merry W Ma, Cameron G McCarthy, Bianca N Islam, Lauren G Fox, James D Mintz, Sebastian Larion, David J Fulton, David W Stepp
The objective of this study is to test the hypothesis that increased muscle mass has positive effects on cardiovascular function. Specifically, we tested the hypothesis that increases in lean body mass caused by deletion of myostatin improves cardiac performance and vascular function. Echocardiography was used to quantify left ventricular function at baseline and after acute administration of propranolol and isoproterenol to assess β -adrenergic reactivity. Additionally, resistance vessels in several beds were removed, cannulated, pressurized to 60 mmHg and reactivity to vasoactive stimuli was assessed...
December 2017: Physiological Reports
Joshua C Tremblay, Kyra Ellen Pyke
Investigations of human conduit artery endothelial function via flow-mediated vasodilation (FMD) have largely been restricted to the reactive hyperemia (RH) technique, wherein a transient increase in shear stress following the release of limb occlusion stimulates upstream conduit artery vasodilation (RH-FMD). FMD can also be assessed in response to sustained increases in shear stress (sustained stimulus (SS)-FMD), most often created with limb heating or exercise. Exercise in particular creates a physiologically-relevant stimulus because shear stress increases, and FMD occurs, during typical day-to-day activity...
November 22, 2017: American Journal of Physiology. Heart and Circulatory Physiology
Gregers Wibe Munch, Ulrik Winning Iepsen, Camilla Koch Ryrsø, Jaya Birgitte Rosenmeier, Bente Klarlund Pedersen, Stefan P Mortensen
Breathlessness during daily activities is the primary symptom in patients with heart failure (HF). Poor correlation between the hemodynamic parameters of left ventricular performance and perceived symptoms suggests that other factors such as skeletal muscle function plays a role in determining exercise capacity. We investigated the effect of six weeks of high-intensity one-legged cycling (HIC; 8x4 at 90% one-legged cycling max) on: 1) the ability to override sympathetic vasoconstriction (arterial infusion of tyramine) during one-legged knee-extensor exercise (KEE); 2) vascular function (arterial infusion of ACh, SNP, tyramine and ATP); 3) exercise capacity in HF patients with reduced ejection fraction (n=8) compared with healthy individuals (n=6)...
November 22, 2017: American Journal of Physiology. Heart and Circulatory Physiology
Shan Xu, Xiaoling Xu, Jisong Zhang, Kejing Ying, Yuquan Shao, Ruifeng Zhang
BACKGROUND: Mitochondrial diseases are a group of multisystem heterogeneous diseases caused by pathologic dysfunction of the mitochondrial respiratory chain. A wide range of clinical expression has been described. However, pulmonary hypertension has rarely been described in association with mitochondrial disease until the past decade, and there is no currently recognized treatment for the pulmonary hypertension complicated with mitochondrial disorder. PATIENT CONCERNS: We reported the case of a 15-year-old boy who presented with shortness of breath and exercise limitation after a cold, and the diagnosis of pulmonary hypertension was confirmed by right heart catheter...
November 2017: Medicine (Baltimore)
Laura E Bagge, Stephen T Kinsey, Justin Gladman, Sönke Johnsen
Whole-body transparency, an effective camouflage strategy in many aquatic species, can be disrupted by environmental and/or physiological stressors. We found that tail-flip escape responses temporarily disrupt the transparency of the anemone shrimp Ancylomenes pedersoni After as few as three tail flips, the previously transparent abdominal muscle became cloudy. Eliciting additional tail flips to the point of exhaustion (16±1 s.e.m.; n=23) resulted in complete opacity, though the original transparency returned after 20-60 min of inactivity...
November 15, 2017: Journal of Experimental Biology
Andrew O Kadlec, Chad Barnes, Matthew J Durand, David D Gutterman
BACKGROUND: Sedentary behavior and obesity are major risk factors for cardiovascular disease. Regular physical activity has independent protective effects on the cardiovascular system, but the mechanisms responsible remain elusive. Recent studies suggest that the protein peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) participates in the response to exercise training. We hypothesized that the arterioles of athletes maintain dilation to flow despite combined inhibition of multiple vasodilators, but loss of PGC-1α renders these vessels susceptible to inhibition of a single vasodilator pathway...
November 11, 2017: American Journal of Hypertension
Kurt J Smith, Ryan L Hoiland, Ryan Grove, Hamish McKirdy, Louise Naylor, Philip N Ainslie, Daniel J Green
The mechanistic role of arterial shear stress in the regulation of cerebrovascular responses to physiological stimuli (exercise and hypercapnia) is poorly understood. We hypothesised that, if shear stress is a key regulator of arterial dilation, then matched increases in shear, induced by distinct physiological stimuli, would trigger similar dilation of the large extra-cranial arteries. Participants ( n = 10) participated in three 30-min experimental interventions, each separated by ≥48 h: (1) mild-hypercapnia (FICO2:∼0...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
Paul A Roberts, Aaron C W Lin, Brett R Cowan, Alistair A Young, Ralph Stewart
Aortic regurgitation (AR) increases the hemodynamic load on both the left ventricle (LV) and the aorta. Vasodilators and beta-blockers both reduce systemic blood pressure, but their relative effects on the LV and aortic function and aortic regurgitant fraction in chronic AR are uncertain. We aimed to compare short-term effects of losartan and metoprolol on LV and aortic function in asymptomatic patients with chronic moderate to severe AR, both at rest and during exercise, using cardiac magnetic resonance (CMR) imaging...
November 8, 2017: International Journal of Cardiovascular Imaging
Kwang-Seok Hong, Kijeong Kim
Maximal whole body exercise leads skeletal muscle blood flow to markedly increase to match metabolic demands, a phenomenon termed exercise hyperaemia that is accomplished by increasing vasodilation. However, local vasodilatory mechanisms in response to skeletal muscle contraction remain uncertain. This review highlights metabolic vasodilators released from contracting skeletal muscle, endothelium, or blood cells. As a considerable skeletal muscle vasodilation potentially results in hypotension, sympathetic nerve activity needs to be augmented to elevate cardiac output and blood pressure during dynamic exercise...
October 2017: Journal of Exercise Rehabilitation
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