Search Results
Results 301 - 350 of 1018
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Kirby Brett S - - 2008
Recent evidence suggests that adenosine triphosphate (ATP) can inhibit vasoconstrictor responses to endogenous noradrenaline release via tyramine in the skeletal muscle circulation, similar to what is observed in contracting muscle. Whether this involves direct modulation of postjunctional alpha-adrenoceptor responsiveness, or is selective for alpha(1)- or alpha(2)-receptors remains unclear. Therefore, in ...
Sugawara Jun - - 2009
BACKGROUND: Regular aerobic exercise improves large artery compliance in middle-aged and older humans. However, the underlying mechanisms are unknown. We tested the hypothesis that the improved central arterial compliance with endurance training is mediated by decreased alpha-adrenergic tone and/or increased endothelial function. METHODS: Seven sedentary healthy adults (60+/-3 years) underwent ...
Duncker Dirk J - - 2008
Exercise is the most important physiological stimulus for increased myocardial oxygen demand. The requirement of exercising muscle for increased blood flow necessitates an increase in cardiac output that results in increases in the three main determinants of myocardial oxygen demand: heart rate, myocardial contractility, and ventricular work. The approximately sixfold ...
Seals Douglas R - - 2008
Aging affects the function and structure of arteries and increases the risk of cardiovascular diseases (CVD). In healthy sedentary adults, aging is associated with increased stiffness (reduced compliance) of large elastic arteries; impaired vascular endothelial function, including reductions in endothelium-dependent dilation (EDD), release of tissue-type plasminogen activator (fibrinolytic capacity) and ...
da Silva Alexandre G - - 2008
This study examined forearm vasodilatation during mental challenge and exercise in 72 obese children (OC; age = 10 +/- 0.1 years) homozygous with polymorphism in the allele 27 of the beta-2-adrenoceptors: Gln27 (n = 61) and Glu27 (n = 11). Forearm blood flow was recorded during 3 min of each ...
Rossi M - - 2008
OBJECTIVES: To test the hypothesis that finger skin vasomotion (FSV), a known factor influencing microvascular blood flow motion, is impaired in SSc patients. Possible relationships between FSV abnormalities and the severity and/or activity of SSc were also investigated. METHODS: FSV was investigated by means of spectral Fourier analysis of finger ...
Pyke K E - - 2008
Exercise elevates shear stress in the supplying conduit artery. Although this is the most relevant physiological stimulus for flow-mediated dilation (FMD), the fluctuating pattern of shear that occurs may influence the shear stress-FMD stimulus response relationship. This study tested the hypothesis that the brachial artery FMD response to a step ...
Lange-Asschenfeldt Christian - - 2008
Exercise training promotes extensive cardiovascular changes and adaptive mechanisms in both the peripheral and cerebral vasculature, such as improved organ blood flow, induction of antioxidant pathways, and enhanced angiogenesis and vascular regeneration. Clinical studies have demonstrated a reduction of morbidity and mortality from cardiovascular disease among exercising individuals. However, evidence ...
Sun Meng-Wei - - 2008
The objective of this study was to examine the effects of moderate and high levels of exercise volume on endothelium-dependent vasodilation and associated changes in vascular endothelial/inducible nitric oxide synthase (eNOS and iNOS) and heme oxygenase (HO). Male Sprague-Dawley rats were assigned to sedentary control, acute (2 weeks), or chronic ...
Shelkovnikov Stan - - 2008
BACKGROUND: Chronic renal insufficiency (CRI) is associated with a high incidence of hypertension (HTN), endothelial dysfunction, atherosclerosis and cardiovascular disease. Sedentary life style increases, whereas regular exercise reduces the risk of cardiovascular disease. This study was designed to test the effect of regular exercise on vasodilatory and vasoconstrictive responses of ...
Walther G - - 2008
AIM: The main purpose of the present study was to assess whether similar vascular adaptive changes could be obtained by long-term intensive training involving predominantly either the lower or the upper limb musculature. METHODS: In 11 cyclists (C), 10 swimmers (S) and 10 sedentary controls (Sed), duplex Doppler ultrasonography was ...
Tschakovsky Michael E - - 2008
This introduction summarizes the topics addressed in the three companion review papers on various issues surrounding exercise and the endothelium. Leading experts in the field discuss the most recent findings regarding the following: (i) nitric oxide and exercise hyperemia, (ii) the response of the endothelium to exercise training, and (iii) ...
Brummitt Jason - - 2008
Massage is a popular treatment choice of athletes, coaches, and sports physical therapists. Despite its purported benefits and frequent use, evidence demonstrating its efficacy is scarce. To identify current literature relating to sports massage and its role in effecting an athlete's psychological readiness, in enhancing sports performance, in recovery from ...
Rush James W E - - 2008
The renin-angiotensin system (RAS) is important for regulating blood pressure and extracellular fluid. The concept of the RAS has recently evolved from a classical systemic endocrine system to an appreciation of local RASs functioning in a paracrine manner, including in the vascular wall. Angiotensin II (AII), the main effector of ...
Palanker Daniel - - 2008
A variety of medical procedures is aimed to selectively compromise or destroy vascular function. Such procedures include cancer therapies, treatments of cutaneous vascular disorders, and temporary hemostasis during surgery. Currently, technologies such as lasers, cryosurgery and radio frequency coagulation, produce significant collateral damage due to the thermal nature of these ...
McAllister Richard M - - 2008
Exercise training is known to induce several adaptations in the cardiovascular system, one of which is increased skeletal muscle blood flow at maximal exercise. Improved muscle blood flow, in turn, could in part be accounted for by augmented endothelium-dependent, nitric oxide (NO)-mediated vasodilation. Studies have indeed demonstrated that endothelium-dependent, NO-mediated ...
Frøbert Ole - - 2008
OBJECTIVE: Oxygen-dependent changes in vascular diameters may be detrimental when the endothelium is dysfunctional. DESIGN: Endothelial responsiveness was evaluated by brachial ultrasound and flow-mediated/nitroglycerin-mediated dilation (FMD/NMD). FMD/NMD was investigated in males with increased risk of cardiovascular disease (mean age 44+/-2 years, n=10) and matched controls without risk factors (44+/-2 years, ...
Heylen Erwan - - 2008
BACKGROUND: Moderate physical activity enhances endothelium-dependent vasorelaxation. Whether the frequency of exercise affects endothelial function is unclear. The purpose of this study was to investigate the effects of various frequencies of training on endothelium-dependent vasorelaxation. DESIGN: Male Wistar rats were trained for 8 weeks on a treadmill at various frequencies ...
Pierce Gary L - - 2008
BACKGROUND: Aerobic exercise training improves vasodilatory capacity of peripheral resistance vasculature and modifies plasma proinflammatory markers in chronic heart failure patients. It is, however, currently unknown whether aerobic exercise has a similar effect in heart transplant recipients (HTR). DESIGN AND METHODS: Eight weeks after transplantation, 14 HTR were randomly assigned ...
Tschakovsky Michael E - - 2008
Despite being the subject of investigation for well over 100 years, the nature of exercising muscle blood flow control remains, in many respects, poorly understood. In this review we focus on the potential role of nitric oxide in vasodilation of muscle resistance vessels during a bout of exercise. Its contribution ...
Norman Barbara - - 2008
Inherited deficiency of skeletal muscle myoadenylate deaminase (mAMPD) is a genetic disorder characterized primarily by a 34C>T transition in exon 2 of the AMPD1 gene. mAMPD deficient individuals exhibit alterations in ATP catabolic flow, resulting in greater adenosine accumulation during high intensity exercise that may possibly enhance exercise-induced hyperaemia. This ...
Arce , Arturo
Chronic disease will never reach its clinical horizon to compromise health if it is attacked at its origin [1]. Knowledge that ones risk for cardiovascular events is related to the severity of endothelial dysfunction, and evidence that exercise training can improve endothelial function, has prompted speculation that measures of vascular ...
Thistlethwaite, John R.
This dissertation examined the effects of a chronic acidosis on vascular function during dynamic handgrip exercise and following post-occlusive reactive hyperemia. Seven males performed hand-grip exercise corresponding to 5% (moderate) and 10% (heavy) of maximal forearm strength during control (CON) and acidosis (acetazolamide 500 mg/d 3 d; AC) conditions. Flow-mediated ...
Thompson, Benjamin Charles
Physical activity can prevent atherosclerotic progression which is characterized by an impaired flow-mediated dilation (FMD) response. Using the postprandial state as a surrogate, some of the mechanisms associated with endothelial dysfunction and physical activity are becoming better understood. PURPOSE: To determine the endothelium-dependent response (FMD) to a high fat meal ...
Haram Per M - - 2008
Endothelial dysfunction is one of the hallmarks of cardiovascular disease and serves as a prognostic marker for forecasting the development and outcome of the disease process. Current pharmacological treatment strategies only incompletely repair endothelial dysfunction whereas exercise training corrects this dysfunction, primarily due to improved production and/or bioavailability of nitric ...
Braith Randy W - - 2008
BACKGROUND: Heart transplantation normalizes central hemodynamics, but endothelial dysfunction persists after transplantation. METHODS: To investigate the effects of aerobic exercise on arterial function, oxidative stress, lipid profile, and sympathetic nervous system activity, 20 heart transplant recipients (age, 54.3 +/- 9.1 years; 17 men, 3 women) were randomly assigned to 12 ...
Downey H Fred - - 2008
BACKGROUND: This investigation examined interactions between expansion of the extracellular fluid volume (ECE), osteopathic lymphatic pump treatment (LPT), and exercise on lymph flow in the thoracic duct of eight instrumented, conscious dogs. METHODS AND RESULTS: After recovery from surgery, LPT was performed for 8 min before and after ECE with ...
Leung Fung Ping - - 2008
Cardiovascular disease (CVD) remains the leading cause of morbidity and premature mortality in both women and men in most industrialized countries, and has for some time also established a prominent role in developing nations. In fact, obesity, diabetes mellitus and hypertension are now commonplace even in children and youths. Regular ...
Bechara Luiz Roberto Grassmann - - 2008
The present study investigated the effect of one bout of moderate-intensity exercise on the adrenergic receptor-dependent and -independent vasoconstrictor response in rat aortas, and the role of nitric oxide (NO) bioavailability on these vasomotor responses. One group of rats was submitted to a 60 min of exercise at approximately 60% ...
Wafai Rafif - - 2008
AIMS: The effects of ischemia and hypercholesterolemia on the function and morphological adaptation of the rabbit hindlimb were assessed. METHODS: In rabbits on normal or cholesterol diet, experiments were performed on days 0-28 following bilateral femoral artery ligation. Calf blood pressure (C(BP)), exercise tolerance, flow reserve, agonist vasodilatation, angiography and ...
Matsumoto Tetsuya - - 2008
BACKGROUND: Periodic acceleration in the direction of the spinal axis through repetitive movement increases the shear stress on the vascular endothelium. In the present study it was assessed whether whole-body periodic acceleration with a new device would enhance endothelial function in sedentary adult volunteers. METHODS AND RESULTS: Twenty-six sedentary subjects ...
Padilla Jaume - - 2008
Normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress area under the curve (peak FMD:SSAUC ratio) has recently been proposed as an approach to control for the large inter-subject variability in reactive hyperemia-induced shear stress; however, the adoption of this approach among researchers has been slow. The present ...
Desgorces François Denis FD Unité de Formation et de Recherche en Sciences et Techniques des Activités Physiques et Sportives, Université Paris Descartes , Paris, France ; IRMES, Institut de Recherche bioMédicale et d'Epidémiologie du Sport , Paris, - - 2008
The study investigated blood markers allowing discriminating physiological responses to on-water rowing races, notably regarding training volume of athletes and race duration. College (COL) and national (NAT) rowers performed a 1000- or 2000-m race. Capillary blood samples obtained before and post-race allowed an analysis of a wide range of serum ...
Kooijman M - - 2008
Flow-mediated dilatation (FMD) of the brachial and radial arteries is an important research tool for assessment of endothelial function in vivo, and is nitric oxide (NO) dependent. The leg skeletal muscle vascular bed is an important territory for studies in exercise physiology. However, the role of endothelial NO in the ...
Sahin Ay┼če Saide - - 2007
In the present study, we analysed the effects of leptin on rabbit aorta and the mechanisms underlying these effects. Leptin (10(-12)-10(-9) m) induced concentration-dependent relaxation in intact rabbit aorta rings precontracted with phenylephrine (10(-6) m). Removal of endothelium abolished the effects of leptin. Pretreatment of rings with N(omega)-nitro-l-arginine methyl ester ...
Muster Alexander J - - 2007
Constriction and relaxation of peripheral conduit arteries in response to exercise and recovery are amenable to noninvasive imaging. Diameter changes in the brachial artery during stationary bicycle pedaling are paradoxical to those in the lower extremities. When exercise is confined to the legs, arteries in the upper extremities constrict while ...
McAllister Richard M - - 2008
Nitric oxide (NO) is potentially involved in several responses to acute exercise. We tested the hypotheses that inhibition of NO formation reduces maximal O(2) delivery to muscle, but does not affect O(2) utilization by muscle, therefore lowering maximal O(2) consumption. To test these hypotheses, swine (approximately 30 kg) drank either ...
Rambaran Curtis - - 2008
To assess the reproducibility of the digital pulse wave response to beta(2)-adrenoreceptor stimulation and to determine if an attenuated response to beta(2)-adrenoceptor stimulation is associated with impaired flow mediated dilatation (FMD). Subjects (n = 20) with endothelial dysfunction (ED), were compared with healthy control subjects (n = 20). Change in ...
Sugita Yoichi - - 2008
Recently, several reports have been published on ultrasonic vascular dilation produced with relatively low-frequency ultrasound. It has been speculated that nitric oxide (NO) is an important factor for this ultrasonic vascular dilation. However, a quantitative relationship between the ultrasound intensity and NO generation was not clarified in these reports. We ...
Gonzales Joaquin U - - 2007
To test the hypothesis that sex influences forearm blood flow (FBF) during exercise, 15 women and 16 men of similar age [women 24.3 +/- 4.0 (SD) vs. men 24.9 +/- 4.5 yr] but different forearm muscle strength (women 290.7 +/- 44.4 vs. men 509.6 +/- 97.8 N; P < 0.05) ...
Lin Wei-Yu - - 2007
Nitric oxide (NO) is synthesized from L-arginine by nitric oxide synthase (NOS). NOS can be inhibited by NG-nitro-L-arginine methyl ester (L-NAME) and stimulated by supplementing the diet with L-arginine. The aim of this study was to investigate the influence of NOS activity on the response of rabbits to chronic partial ...
Nossaman Bobby D - - 2007
The free radical peroxynitrite (ONOO-) is formed in biological systems from the reaction of nitric oxide (NO) with superoxide (O2-) and can react with protein and nonprotein thiol groups to produce tissue injury. However, these pathologic actions of (ONOO-) may have been overemphasized, in that (ONOO-) has vasorelaxant properties through ...
Goto Chikara - - 2007
BACKGROUND: Long-term moderate-intensity exercise augments endothelium-dependent vasodilation through an increase in nitric oxide (NO) production. The purpose of this study was to determine the effects of different intensities of acute exercise on hemodynamics in humans. METHODS: We evaluated forearm blood flow (FBF) responses to different intensities of exercise (mild, 25% ...
Chen Yifan - - 2007
Tempol catalyzes the formation of H(2)O(2) from superoxide and relaxes blood vessels. We tested the hypothesis that the generation of H(2)O(2) by tempol in vascular smooth muscle cells during oxidative stress contributes to the vasorelaxation. Tempol and nitroblue tetrazolium (NBT) both metabolize superoxide in vascular smooth muscle cells, but only ...
Rojek Amanda M - - 2007
Venous occlusion plethysmography (VOP) is a technique used for the non-invasive measurement of limb blood flow. A fundamental technical consideration of venous occlusion plethysmography is that the limb in question must be placed above heart level. However, in light of advances in technology and methodology, the necessity of this has ...
Marshall Janice M - - 2007
The role of adenosine in exercise hyperaemia has been controversial. Accumulating evidence now demonstrates that adenosine is released into the venous efflux of exercising muscle and that adenosine is responsible for 20-40% of the maintained phase of the muscle vasodilatation that accompanies submaximal and maximal contractions. This adenosine is mainly ...
Dyson K S - - 2007
This investigation set out to determine the effect of 56 days of head-down tilt bed rest (HDBR) and an exercise countermeasure on endothelial dependent and independent vascular function. 24women took part in this study. 8 subjects completed lower body resistance and aerobic exercise (EX, treadmill running 3-4 days per week ...
Harris Ryan A - - 2007
Flow-mediated dilation (FMD) has been established as a reliable noninvasive measurement of endothelial function. The reproducibility of FMD under resting conditions has previously been reported; however, the reproducibility of FMD in response to exercise remains to be investigated. On two separate days, we determined if flow-mediated dilation is reproducible in ...
Trejo-Gutierrez Jorge F - - 2007
Abnormal blood lipids are a significant cardiovascular health risk. Drug therapy and diet continue to be standard management strategies. However, considerable evidence supports physical activity and exercise as having a positive impact on abnormal lipids and such are often recommended as adjunctive interventions. The purpose of this review is to ...
Duncker Dirk J - - 2007
Coronary blood flow is tightly coupled to myocardial oxygen consumption to maintain a consistently high level of myocardial oxygen extraction over a wide range of physical activity. This tight coupling has been proposed to depend on periarteriolar oxygen tension, signals released from cardiomyocytes (adenosine acting on K(ATP) channels) and the ...
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