Search Results
Results 351 - 400 of 1018
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Ibrahim N N I N - - 2007
Pulse-wave analysis (PWA) combined with pharmacological challenges has recently been used as a method to measure endothelial function. This involved administration of glyceryl trinitrate (GTN), followed by salbutamol as endothelium-independent and -dependent vasodilators, respectively. The duration of GTN effect needs to be established before the administration of salbutamol. Baseline augmentation ...
Zacchigna Serena - - 2007
Although the angiogenic effect of vascular endothelial growth factor (VEGF) is widely recognized, a central question concerns whether the vessels formed on its overexpression effectively increase tissue perfusion in vivo. To explore this issue, here we exploit AAV vectors to obtain the prolonged expression of VEGF and angiopoietin-1 (Ang1) in ...
McGowan Cheri L - - 2007
Isometric HG (handgrip) training lowers resting arterial BP (blood pressure), yet the mechanisms are elusive. In the present study, we investigated improved systemic endothelial function as a mechanism of arterial BP modification following isometric HG training in normotensive individuals. This study employed a within-subject repeated measures design primarily to assess ...
Sugawara Jun - - 2007
Endurance training improves endothelium-dependent vasodilation, yet it does not increase basal blood flow in the legs. We determined the effects of a 3-mo aerobic exercise intervention on basal leg blood flow and alpha-adrenergic vasoconstriction and nitric oxide (NO) release in seven apparently healthy middle-aged and older adults (60 +/- 3 ...
Rassaf Tienush - - 2007
Nitrite is the main oxidation product of nitric oxide (NO) in plasma. It sensitively reflects changes in endothelial NO synthase (eNOS) activity under fasting conditions and serves as an endocrine NO donor, contributing to the regulation of blood flow through reaction with haemoglobin. As NO is necessary to maintain an ...
O'Leary Donal S - - 2007
Ischemia of active skeletal muscle evokes a powerful blood pressure-raising reflex termed the muscle metaboreflex (MMR). MMR activation increases cardiac sympathetic nerve activity, which increases heart rate, ventricular contractility, and cardiac output (CO). However, despite the marked increase in ventricular work, no coronary vasodilation occurs. Using conscious, chronically instrumented dogs, ...
Zhang Peng - - 2007
To study the effects of different reactive oxygen species (ROS) on the resting tension of porcine coronary artery rings and to identify the effects of genistein (GEN), resveratrol (RES) and 17beta-estradiol (EST) on ROS-elicited vasoconstriction, porcine coronary rings were prepared and mounted in an organ bath and, after an equilibration ...
VanTeeffelen Jurgen W G E - - 2007
The endothelial glycocalyx is a hydrated mesh of polysaccharides and adsorbed plasma proteins that forms the true interface between the flowing blood and the endothelium. We hypothesized in the present study that competitive binding of heparin to glycocalyx-associated proteins would affect glycocalyx barrier properties and mechanotransduction of shear stress to ...
Juel C - - 2007
AIM: Potassium (K(+)) released from contracting skeletal muscle is considered a vasodilatory agent. This concept is mainly based on experiments infusing non-physiological doses of K(+). The aim of the present study was to investigate the role of K(+) in blood flow regulation. METHODS: We measured leg blood flow (LBF) and ...
Kim Yu-Sok - - 2007
Dynamic cerebral autoregulation (CA) is challenged by exercise and may become less effective when exercise is exhaustive. Exercise may increase arterial glucose concentration, and we evaluated whether the cerebrovascular response to exercise is affected by hyperglycemia. The effects of a hyperinsulinemic euglycemic clamp (EU) and hyperglycemic clamp (HY) on the ...
Bedaiwy Mohamed A - - 2007
The objective of this study was to describe the different surgical approaches involved in harvesting and heterotopic autotransplantation of intact ovaries with microvascular anastomosis. Twenty-one synchronized Merino sheep underwent harvesting of their intact ovaries with vascular pedicles. Autotransplantation was performed with fresh (n = 6) and cryopreserved-thawed (C-T; n = ...
Rundell Kenneth W - - 2007
This study investigated the effects of particulate matter (PM) with aerodynamic diameter 0.02-1 microm (noted as PM1) inhalation during exercise on conduit artery and microvascular function. Inhalation of internal combustion-derived PM is associated with cardiovascular mortality and morbidity. Direct action of PM on the vascular endothelium is likely, as a ...
Bronquard Cécile - - 2007
The aim of this study was to investigate the in vitro vasomotor properties of rat extra-and intralobar pulmonary veins (PVs) related to their localization and to assess the modulatory role of endothelium on these properties. Segments from PVs were mounted in small vessel myograph and stretched at various diameters (D(10), ...
Akata Takashi - - 2007
General anesthetics threaten cardiovascular stability by causing changes in cardiac function, vascular reactivity, and cardiovascular reflexes and significantly alter distribution of cardiac output to various organs. Their overall impact is often systemic hypotension, which is attributable to myocardial depression, peripheral vasodilation, and attenuated sympathetic nervous system activity. However, one could ...
Thengchaisri Naris - - 2007
OBJECTIVE: Exercise training has been shown to restore vasodilation to nitric oxide synthase (NOS) activation in arterioles distal to coronary artery occlusion. Because reactive oxygen species are generated during NOS uncoupling and the production of vasodilator H2O2 is increased during exercise in patients with coronary disease, we proposed that H2O2 ...
Jeppesen Peter - - 2007
PURPOSE: To study the diameter response of retinal arterioles as a function of the arteriolar diameter. METHODS: Ten healthy young volunteers aged 22 to 33 years were subjected to diameter measurement of four successive segments of a retinal arteriole with a retinal vessel analyzer (RVA). At each of the segments, ...
Alomari Mahmoud A - - 2007
BACKGROUND: Few studies have examined the time-course of localized exercise training on regional blood flow in humans. The study examined the influence of handgrip exercise training on forearm reactive hyperemic blood flow and vascular resistance in apparently healthy men. METHODS: Forearm blood flow and vascular resistance were evaluated, in 17 ...
Asbeutah Akram M - - 2007
To investigate if noradrenaline (NA) and 5-hydroxyptamine (5-HT) drugs induce responses of isolated control and varicose veins are altered by removal of the endothelium. SUBJECTS #ENTITYSTARTX00026; Specimens of the great saphenous vein (GSV) were obtained from 12 subjects with primary varicose veins and 12 subjects from donor vessels at cardiac ...
Padilla Jaume - - 2007
The measurement of flow-mediated dilation using high-resolution ultrasound has been utilized extensively in interventional trials evaluating the salutary effect of drugs and lifestyle modifications (i.e. diet or exercise training) on endothelial function; however, until recently researchers have not used flow-mediated dilation to examine the role of a single bout of ...
Yamazaki Fumio - - 2007
The influence of hyperoxia on the cutaneous vasodilator responses to iontophoretic applications of acetylcholine (ACh) and sodium nitroprusside (SNP) was examined in healthy subjects. The breathing of 100% O(2) decreased (P < 0.05) the vasodilator response to Ach, but not to SNP, suggesting that hyperoxia attenuates endothelial-mediated vasodilation of the ...
Pyke Kyra E - - 2007
We investigated the independent contributions of the peak and continued reactive hyperemia on flow-mediated dilation (FMD). 1) For the duration manipulation experiment (DME), 10 healthy males experienced reactive hyperemia durations of 10 s, 20 s, 30 s, 40 s, 50 s, or full reactive hyperemia (RH). 2) For the peak ...
Martin Elizabeth A - - 2007
' We previously demonstrated a bimodal distribution of forearm vasodilator responsiveness to adenosine (ADO) infusion in the brachial arteries of human subjects. We also demonstrated that ADO receptor antagonism blunted exercise hyperaemia during heavy rhythmic handgripping, but vasodilator responses to exogenous ADO were only blunted in ADO responders. In this ...
Schrage William G - - 2007
In older humans, infusions of endothelial agonists suggest endothelial dysfunction, due in part to less nitric oxide (NO)- and prostaglandin (PG)-mediated vasodilatation, and a shift toward PG-mediated vasoconstriction. Ageing can also be associated with lower exercise blood flow (exercise hyperaemia), but the vascular mechanisms mediating this remain unknown. Notably, in ...
Winter Kelly L - - 2007
Clinical observations suggest a primary cardiotoxic role in fatal Chironex fleckeri stings. The limited research available indicates that Chiropsella bronzie venom acts in a similar manner although appears to be less potent. The aim of the present study was to elucidate the vascular effects of C. fleckeri and C. bronzie ...
Donato Anthony J AJ Department of Health and Kinisiology, Texas A and M University, College Station, TX 77843, - - 2007
Ageing is associated with increased leg vascular resistance and reductions in leg blood flow during rest and exercise, potentially predisposing older adults to a host of functional and cardiovascular complications. The purpose of these studies was to examine the effects and possible mechanisms of ageing and exercise training on arteriolar ...
Kojima Shinji - - 2006
The aim of this study is to determine whether a questionnaire-based method using the Veterans Specific Activity Questionnaire (VSAQ) is a practical tool for the development of a safe exercise program to prevent a reduction in physical performance. One hundred and twenty-one senior residents of Yakage, Okayama, agreed to voluntarily ...
de Moraes Camila - - 2007
A strong association between the benefits of physical exercise on the cardiovascular disease with an improvement of the endothelium-derived relaxing factor production has been consistently shown. The purpose of this study was to evaluate the effect of exercise training associated with high caloric diet in the reactivity of rat mesenteric ...
Figard Hélène - - 2006
Using female 4-week-old Sprague-Dawley rats, we investigated the effects of 14 weeks of progressive strength isometric training on endothelium dysfunction after estrogen deficiency. We also proposed possible mechanism(s) by which such training acted on endothelium-dependent vasodilation in thoracic aortic rings. Rats were randomly divided into 4 groups of 8 rats: ...
Brothers R Matthew - - 2006
It is well established that metabolic inhibition of adrenergic vasoconstriction contributes to the maintenance of adequate perfusion to exercising skeletal muscle. However, little is known regarding nonadrenergic vasoconstriction during exercise. We tested the hypothesis that a non-adrenergic vasoconstrictor, angiotensin II (AngII), would be less sensitive to metabolic inhibition than an ...
Chan Sammy Y - - 2006
PURPOSE: Atherosclerosis contributes to cardiovascular mortality and morbidity even with aggressive lipid management. Our objective is to determine whether a combined pharmacological and lifestyle intervention can improve atherosclerosis. METHODS: We conducted a 2-year observational study at a specialized clinic in a tertiary care hospital. One hundred fifty-six subjects with coronary ...
DeLorey Darren S - - 2007
Our laboratory has previously reported a decline in sympathetic nervous system restraint of skeletal muscle blood flow during prolonged mild-intensity exercise. This decline may be explained by a decrease in alpha(1)- and alpha(2)-adrenergic receptor responsiveness over time. Thus the purpose of the present study was to investigate the effect of ...
Martin Elizabeth A - - 2006
We previously demonstrated a bimodal distribution of vasodilator responsiveness to adenosine (Ado) infusion in human subjects, despite similar responses to exercise between subgroups [subjects responsive to Ado infusion (Ado responders) and subjects with blunted vasodilator responses to Ado infusion (Ado nonresponders]). (Martin EA, Nicholson WT, Eisenach JH, Charkoudian N, and ...
McGowan Cheri L - - 2006
Bilateral isometric handgrip (IHG) training lowers resting arterial blood pressure (BP) in medicated hypertensives. Numerous mechanisms have been suggested, but have yet to be investigated. One such mechanism is that of improved systemic endothelial-dependent vasodilation. The purpose of this investigation was twofold: (1) to determine if Bilateral IHG training had ...
Haram Per Magnus - - 2006
BACKGROUND: Regular exercise training has emerged as a powerful tool to improve endothelium-dependent vasorelaxation. However, little is known about the magnitude of change and the permanence of exercise-induced adaptations in endothelial function. DESIGN: Rats were randomized to either 6 weeks of regular exercise or one bout of exercise. Rats were ...
Thijssen Dick H J - - 2006
The physiological aging process is associated with endothelial dysfunction, as assessed by flow-mediated dilation (FMD). Aging is also characterized by increased sympathetic tone. Therefore, the aim of the present study is to assess whether acute changes in sympathetic activity alter FMD in the leg. For this purpose, the FMD of ...
Yamazaki Fumio - - 2006
To elucidate the characteristics of vasomotor control in glabrous and nonglabrous skin during dynamic exercise, we compared the vascular responses in both areas to increasing core temperature during the cycle exercise for 30 min at different intensities in the range 20-60% of peak oxygen consumption (VO(2peak)) in a total of ...
Merkus Daphne - - 2006
Withdrawal of the endothelin (ET)-mediated vasoconstrictor influence contributes to metabolic coronary vasodilation during exercise. Because production of nitric oxide (NO) and prostanoids increases with increasing shear stress and because NO and prostanoids are able to modify the release of ET, we hypothesized that the withdrawal of ET-mediated coronary vasoconstriction during ...
Ozcan Hasan - - 2006
PURPOSE: Examine the effects of incremental and submaximal exercise on structural and hemodynamic changes in the brachial artery flow parameters using Doppler ultrasonography. MATERIALS AND METHODS: Twenty four healthy sedentary males (aged 19.54+/-0.59) performed submaximal (15 minutes heart rate to 75% maximal) and incremental (workload was increased 20W every 3 ...
Vincent Michelle A - - 2006
Intense exercise and insulin each increases total limb blood flow and recruits muscle capillaries, presumably to facilitate nutrient exchange. Whether mixed meals or light exercise likewise recruits capillaries is unknown. We fed 18 (9 M, 9 F) healthy volunteers a 480-kcal liquid mixed meal. Plasma glucose, insulin, brachial artery flow, ...
Hand Brian D - - 2006
Peripheral vasculature resistance can play an important role in affecting blood pressure and the development of cardiovascular disease. A better understanding of the genes that encode vasodilators, such as adenosine, will provide insight into the mechanisms underlying cardiovascular disease. We tested whether the adenosine monophosphate deaminase-1 (AMPD1) C34T gene polymorphism ...
Brunnekreef Jaap J - - 2006
Despite the social impact of repetitive strain injury (RSI), little is known about its pathophysiological mechanism. The main objective of this study was to assess the local muscle oxygenation (mVO2) and blood flow (mBF) of the forearm in individuals with RSI during isometric contractions of the forearm. We employed the ...
McGowan Cheri L - - 2006
Previous work from our laboratory demonstrated that isometric handgrip (IHG) training improved local, endothelium-dependent vasodilation in medicated hypertensives [McGowan CL (PhD Thesis), 2006; McGowan et al. Physiologist 47: 285, 2004]. We investigated whether changes in the capacity of smooth muscle to dilate (regardless of endothelial factors) influenced this training-induced change, ...
Tokizawa Ken - - 2006
Our previous studies showed that venous occlusion or passive stretch of the lower limb, assuming a mechanical stimulus, attenuates the vasoconstriction in the non-exercised forearm during postexercise muscle ischaemia (PEMI) of the upper limb. In this study, we investigated whether a metabolic stimulus to the lower limb induces a similar ...
Walser Buddy - - 2006
Omega-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have beneficial effects on the heart and vasculature. We tested the hypothesis that 6 weeks of dietary supplementation with DHA (2.0 g/day) and EPA (3.0 g/day) enhances exercise-induced increases in brachial artery diameter and blood flow during ...
Martin Elizabeth A - - 2006
To gain insight into the role of adenosine (Ado) in exercise hyperemia, we compared forearm vasodilation induced by intra-arterial infusion of three doses of Ado with vasodilation during three workloads of forearm handgrip exercise in 27 human subjects. We measured forearm blood flow (FBF) using Doppler ultrasound and mean arterial ...
de Groot Patricia C E - - 2006
We demonstrate that extensive arterial vascular adaptations occur within 3-8 wk of inactivity in humans. We put forth the hypothesis that the diameter decrease represents an adaptation to a lack of variation in peak shear stress. Furthermore, an enhanced flow-mediated dilation in deconditioned arteries implies that functional vascular adaptations to ...
Iemitsu Motoyuki - - 2006
Increase in arterial stiffness is associated with aging, which is improved by regular exercise. Endothelin (ET) system has crucial roles in regulating vascular tone and in the progression of atherosclerosis. We hypothesized that molecular variations (ie, gene polymorphisms) in ET-related gene might affect exercise-induced improvement in arterial stiffness with age ...
Jasperse Jeffrey L - - 2006
This review summarizes and examines the evidence from experiments using animal models to determine the effect of endurance exercise training on endothelium-dependent dilation in the arterial circulation. The response of the endothelium to exercise training is complex and depends on a number of factors that include the duration of the ...
Shibata Masahiro - - 2006
The objective of this study was to evaluate whether the nitric oxide (NO) released from vascular endothelial cells would decrease vessel wall oxygen consumption by decreasing the energy expenditure of mechanical work by vascular smooth muscle. The oxygen consumption rate of arteriolar walls in rat cremaster muscle was determined in ...
Schrage William G - - 2006
ATP-sensitive potassium (KATP) channels have been suggested to contribute to coronary and skeletal muscle vasodilation during exercise, either alone or interacting in a parallel or redundant process with nitric oxide (NO), prostaglandins (PGs), and adenosine. We tested the hypothesis that KATP channels, alone or in combination with NO and PGs, ...
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