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Results 701 - 750 of 1060
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MacLean P S - - 2000
Among the many effects of exercise is the induction of glucose transporter (GLUT 4) expression in skeletal muscle. In this review, we examine the intracellular signals that may mediate the exercise-induced increase in GLUT4 gene transcription. This induction is likely to be dependent upon intracellular calcium concentrations and the energy ...
Vezina M J - - 2000
OBJECTIVE: To evaluate the relative activation amplitudes from 3 abdominal and 2 trunk extensor muscle sites in healthy subjects performing the pelvic tilt, abdominal hollowing, and level 1 of the trunk stability test (TST level 1) exercises and to compare the activation amplitudes among muscle sites and exercises. DESIGN: Prospective ...
Pilegaard H - - 2000
Exercise training elicits a number of adaptive changes in skeletal muscle that result in an improved metabolic efficiency. The molecular mechanisms mediating the cellular adaptations to exercise training in human skeletal muscle are unknown. To test the hypothesis that recovery from exercise is associated with transcriptional activation of specific genes, ...
Kingwell B A - - 2000
Accumulating data suggest that nitric oxide (NO) is important for both coronary and peripheral hemodynamic control and metabolic regulation during exercise. Although still controversial, NO of endothelial origin may potentiate exercise-induced hyperemia. Mechanisms of release include both acetylcholine derived from the neuromuscular junction and elevation in vascular shear stress. A ...
Febbraio M A - - 2000
To examine the effect of exercise on heat shock protein (HSP) 72 mRNA expression in skeletal muscle, five healthy humans (20 +/- 1 yr; 64 +/- 3 kg; peak O(2) uptake of 2.55 +/- 0.2 l/min) cycled until exhaustion at a workload corresponding to 63% peak O(2) uptake. Muscle was ...
Goto M - - 2000
Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1), a cold-inducible coactivator of nuclear receptors, stimulates mitochondrial biogenesis and respiration in muscle cells. In the present study, we first cloned a rat PGC-1 gene from a brown adipose tissue cDNA library which encodes a predicted 796-amino-acid protein and exhibits respectively 98% and 95% ...
Bhandari A - - 2000
PURPOSE: Endurance exercise training is associated with enhanced glucose uptake and hence improvement in carbohydrate metabolism. Glucose transport (GLUT) membrane proteins are regulated by a variety of physiological stimuli, including exercise. In limb muscle, both acute exercise and endurance training enhance the expression of the skeletal muscle transporter, GLUT-4. The ...
Richardson R S - - 2000
Angiogenesis is a component of the multifactoral adaptation to exercise training, and vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation. However, there is limited evidence supporting the role of VEGF in the exercise training response. Thus we studied mRNA levels of VEGF, using ...
Horowitz J F - - 2000
Endurance training increases fatty acid oxidation (FAO) and skeletal muscle oxidative capacity. However, the source of the additional fat and the mechanisms for increasing FAO capacity in muscle are not clear. We measured whole body and regional lipolytic activity and whole body and plasma FAO in six lean women during ...
Tarnopolsky M A - - 2000
Females show a lower respiratory exchange ratio (RER) than males during submaximal endurance exercise, which translates into a proportionately lower carbohydrate and higher fat oxidation. Data from rodents show that 17-beta-estradiol may mediate these metabolic differences. 17-beta-estradiol supplementation in humans is less convincing; however, two studies found a reduction in ...
Dean D - - 2000
Studies in rats suggest that increases in fatty acid oxidation in skeletal muscle during exercise are related to the phosphorylation and inhibition of acetyl-CoA carboxylase (ACC), and secondary to this, a decrease in the concentration of malonyl-CoA. Studies in human muscle have not revealed a consistent decrease in the concentration ...
Wolfe R R - - 2000
Active persons ingest protein supplements primarily to promote muscle strength, function, and possibly size. Currently, it is not possible to form a consensus position regarding the benefit of protein or amino acid supplements in exercise training. Determination of whether supplements are beneficial has been hampered by the failure to select ...
Fehrenbach E - - 2000
Heat shock proteins (HSP) represent cell-protective and antioxidant systems that may be induced by reactive oxygen species, cytokines, and hyperthermia. In the present study, we evaluated the influence of heavy endurance exercise and training on HSP27 and HSP70 in peripheral leukocytes of 12 athletes (before and at 0, 3, and ...
Fujii N - - 2000
The 5'AMP-activated protein kinase (AMPK) is stimulated by contractile activity in rat skeletal muscle. AMPK has emerged as an important signaling intermediary in the regulation of cell metabolism being linked to exercise-induced changes in muscle glucose and fatty acid metabolism. In the present study, we determined the effects of exercise ...
Goodyear L J - - 2000
Physical exercise increases the rate of glucose transport into contracting skeletal muscles by a mechanism that involves translocation of the GLUT4 glucose transporter to the cell surface. This brief report will discuss an emerging hypothesis that suggests that the AMP-activated protein kinase is a key signaling intermediary leading to exercise-stimulated ...
Greiwe J S - - 2000
Exercise increases the expression of lipoprotein lipase (LPL) and GLUT-4 in skeletal muscle. Intense exercise increases catecholamines, and catecholamines without exercise can affect the expression of both LPL and GLUT-4. To test the hypothesis that adrenergic-receptor signaling is central to the induction of LPL and GLUT-4 by exercise, six untrained ...
Noakes T D - - 2000
A popular concept in the exercise sciences holds that fatigue develops during exercise of moderate to high intensity, when the capacity of the cardiorespiratory system to provide oxygen to the exercising muscles falls behind their demand inducing "anaerobic" metabolism. But this cardiovascular/anaerobic model is unsatisfactory because (i) a more rigorous ...
Reynolds T H TH - - 2000
The purpose of the present study was to examine the effect of detraining on the glucose transport system after short-term swim training (5 days), long-term swim training (5 wk), and treadmill run training (5 wk). Skeletal muscles were isolated from female Wistar rats at 24 or 48 h posttraining. SST ...
González B - - 2000
Skeletal muscle fibres of untrained animals experience a stress response following exercise. This study was aimed at investigating whether chronic exercise modulates stress proteins of 70 kDa (HSP70s) in skeletal muscle. In the soleus muscle of Wistar rats, adherence to an incremental programme of treadmill running (IPTR) of 3 months ...
Tripathi Y B - - 2000
In ayurvedic system of medicine, it is considered that a living system is made of panch-mahabuta, in the form of Vata, pitta and kapha at the physical level and satwa, raja and tama at the mental level. This covers the psychosomatic constitution and commonly known as the Tridosh theory. The ...
Gavin T P - - 2000
Acute exercise increases vascular endothelial growth factor (VEGF), transforming growth factor-beta(1) (TGF-beta(1)), and basic fibroblast growth factor (bFGF) mRNA levels in skeletal muscle, with the greatest increase in VEGF mRNA. VEGF functions via binding to the VEGF receptors Flk-1 and Flt-1. Captopril, an angiotensin-converting enzyme inhibitor, has been suggested to ...
Kingwell B A - - 2000
1. Accumulating animal and human data suggest that nitric oxide (NO) is important for both coronary and peripheral haemodynamic control and metabolic regulation during performance of exercise. 2. While still controversial, NO of endothelial origin is thought to potentiate exercise-induced hyperaemia, both in the peripheral and coronary circulations. The mechanism ...
Juel C - - 2000
Six human subjects performed one-legged knee extensor exercise (90 +/- 4 W) until fatigue (exercise time 4.6 +/- 0.8 min). Needle biopsies were obtained from vastus lateralis muscle before and immediately after exercise. Production of giant sarcolemmal vesicles from the biopsy material was used as a membrane purification procedure, and ...
Hasten D L - - 2000
We determined whether short-term weight-lifting exercise increases the synthesis rate of the major contractile proteins, myosin heavy chain (MHC), actin, and mixed muscle proteins in nonfrail elders and younger women and men. Fractional synthesis rates of mixed, MHC, and actin proteins were determined in seven healthy sedentary 23- to 32-yr-old ...
Geers C - - 2000
CO(2) produced within skeletal muscle has to leave the body finally via ventilation by the lung. To get there, CO(2) diffuses from the intracellular space into the convective transport medium blood with the two compartments, plasma and erythrocytes. Within the body, CO(2) is transported in three different forms: physically dissolved, ...
Gavin T P - - 2000
Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-beta(1) (TGF-beta(1)) mRNA increase in rat skeletal muscle in response to a single acute exercise bout. Nitric oxide (NO) is released locally by muscle vascular endothelium and muscle fibers during exercise, contributes to the blood flow response ...
Kiilavuori K - - 2000
The improvement of exercise capacity in patients with chronic heart failure (CHF) by physical training has been connected with reversal of the abnormalities in muscle fiber distribution and with the reduced activity of the enzymes of oxidative metabolism in skeletal muscle. However, the change in fiber type distribution induced by ...
Ojuka E O - - 2000
Exercise acutely stimulates muscle glucose transport and also brings about an adaptive increase in the capacity of muscle for glucose uptake by inducing increases in GLUT-4 and hexokinase.(1) Recent studies have provided evidence that activation of AMP protein kinase (AMPK) is involved in the stimulation of glucose transport by exercise. ...
Sanchez H - - 2000
In order to examine whether immunosuppressive treatment could be responsible for the reduced exercise capacity of heart transplant recipients (HTR), we studied the effects of long-term immunosuppressive treatment with cyclosporin A (CsA) and its vehicle (2/3 cremophor and 1/3 alcohol diluted in olive oil) on in situ mitochondrial respiration of ...
Rasmussen B B - - 2000
This study was designed to determine the response of muscle protein to the bolus ingestion of a drink containing essential amino acids and carbohydrate after resistance exercise. Six subjects (3 men, 3 women) randomly consumed a treatment drink (6 g essential amino acids, 35 g sucrose) or a flavored placebo ...
Kraniou Y - - 2000
To investigate the effect of exercise on GLUT-4, hexokinase, and glycogenin gene expression in human skeletal muscle, 10 untrained subjects (6 women and 4 men, 21.4 +/- 1.2 yr, 66.3 +/- 5.0 kg, peak oxygen consumption = 2.30 +/- 0.19 l/min) exercised for 60 min on a cycle ergometer at ...
Bergh U - - 2000
In two articles Timothy Noakes proposes a new physiological model in which skeletal muscle recruitment is regulated by a central "govenor," specifically to prevent the development of a progressive myocardial ischemia that would precede the development of skeletal muscle anaerobiosis during maximal exercise. In this rebuttal to the Noakes' papers, ...
Turchanowa L - - 2000
BACKGROUND: Physical exercise and testosterone administration result in a series of adaptive anabolic phenomena in the skeletal muscle. The role of polyamines in these processes has been poorly explored. DESIGN: We measured the activities of polyamine-synthesising enzymes, ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) and polyamine content in skeletal muscle ...
Liu G - - 2000
The operation methods, clinical classification, postoperative function exercise of gluteal muscles contracture were investigated. Clinically and retrospectively, treatment of 1280 patients with gluteal muscles contracture, being subjected to a "Z-shaped" release lengthening operation and efficiency exercise, was clearly standardized. All the cases were followed up from 3 months to 2 ...
Kadi F - - 2000
The purpose of this study was to investigate the immunohistochemical expression of androgen receptors (AR) in human vastus lateralis and trapezius muscles and to determine whether long-term strength training and self-administration of androgenic-anabolic steroids are accompanied by changes in AR content. Biopsy samples were taken from eight high-level power-lifters (P), ...
Richardson R S - - 2000
Skeletal muscle and cardiovascular system responses to exercise are so closely entwined that it is often difficult to determine the effector from the affector. The purpose of this manuscript and its companion papers is to highlight (and perhaps assist in unraveling) the interdependency between skeletal muscle and the cardiovascular system ...
Vierck J - - 2000
It is generally accepted that the primary mechanisms governing skeletal muscle hypertrophy are satellite cell activation, proliferation, and differentiation. Specific growth factors and hormones modulate satellite cell activity during normal muscle growth, but as a consequence of resistance exercise additional regulators may stimulate satellite cells to contribute to gains in ...
Rennie M J - - 2000
Sustained dynamic exercise stimulates amino acid oxidation, chiefly of the branched-chain amino acids, and ammonia production in proportion to exercise intensity; if the exercise is intense enough, there is a net loss of muscle protein (as a result of decreased protein synthesis, increased breakdown, or both); some of the amino ...
Hamilton M T - - 2000
Skeletal muscle physiology and biochemistry is an established field with Nobel Prize-winning scientists, dating back to the 1920s. Not until the mid to late 1960s did there appear a major focus on physiological and biochemical training adaptations in skeletal muscle. The study of adaptations to exercise training reveals a wide ...
Moulias R - - 1999
Sarcopenia is a constant in aging. Observed over long periods, it can reach 1% per year. But it is such a tenuous phenomenon that it cannot be observed over short periods at steady state. The aging phenomenon mainly hits fibers, Type II but on aged muscle thin, normal, and hypertrophic ...
DiMauro S - - 1999
The syndrome of exercise intolerance, cramps, and myoglobinuria is a common presentation of metabolic myopathies and has been associated with several specific inborn errors of glycogen or lipid metabolism. As disorders in fuel utilization presumably impair muscle energy production, it was more than a little surprising that exercise intolerance and ...
Prior B M - - 1999
Increases in skeletal muscle (1)H-NMR transverse relaxation time (T2) observed by magnetic resonance imaging have been used to map whole muscle activity during exercise. Some studies further suggest that intramuscular variations in T2 after exercise can be used to map activity on a pixel-by-pixel basis by defining an active T2 ...
Deschenes M R - - 1999
PURPOSE: This study was conducted to determine whether exercise-induced improvements in capillarity in muscle with peripheral arterial insufficiency (PAI) was accompanied by endothelial cell mitosis, and whether that response could be explained by changes in the expression of basic fibroblast growth factor (bFGF), a known mitogen. METHODS: After bilateral ligation ...
Ohira Y - - 1999
After 2 or 4 mo of bed rest (6 degrees head-down tilt) and 1 mo of ambulation, there was a tendency toward a higher percentage of fibers expressing fast myosin heavy chain (MHC) isoforms and a de novo appearance of fibers coexpressing type I+IIa+IIx and IIa+IIx MHC in human soleus ...
Martineau L C - - 1999
The effects of acute exercise on myocardial content of glut-1 and glut-4 transporters, insulin and IGF-1 receptors were assessed in control and chronically exercised 24-month-old C57B1/6 mice. Myocardial glut-1, glut-4, insulin receptor (Ins R) and insulin like growth factor-1 receptor (IGF-1 R) protein levels were unaffected by 36 weeks of ...
Schrauwen P - - 1999
OBJECTIVE: The new uncoupling proteins, UCP2 and UCP3, are thought to play a role in energy efficiency in humans. Endurance training has been suggested to have effects on resting metabolic rate and energy efficiency. We therefore determined UCP2 and UCP3 mRNA levels in skeletal muscle of trained and untrained male ...
Roberts C K - - 1999
This study examined the effects of acute exercise on skeletal muscle nitric oxide synthase (NOS) activity. Female Sprague-Dawley rats were divided into three groups: control, exercise, and exercise + N(G)-nitro-L-arginine methyl ester (L-NAME). In the exercise + L-NAME group, L-NAME was administered in the drinking water (1 mg/ml) for 2 ...
Paroo Z - - 1999
Estrogen has been shown to reduce post-exercise skeletal muscle damage. Exercise-induced muscle damage may be a factor in the elevated post-exercise expression of heat-shock proteins (HSPs). Thus, the present investigation was conducted in order to examine the influence of estrogen on post-exercise levels of HSP 72 and heat-shock cognate, HSC ...
Hughson R L - - 1999
At the onset of exercise, the cardiovascular system adapts with a series of integrated responses to meet the metabolic demands of the exercising muscles. The importance of rapid increases in cardiac output and local muscle blood flow has been established by showing that small decreases in O2 supply at the ...
Radák Z - - 1999
Moderate daily exercise is known to be beneficial to health, reducing risks of a number of age-related disorders. Molecular mechanisms that bring about these effects are not clear. In contrast, it has been claimed that some types of prolonged physical exertion are detrimental to health because active oxygen species are ...
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